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Open Cthulhu HPLed SRD Release 1.0a

Credits The Open Cthulhu HPLed System Reference Document (SRD) v1.0a draws heavily upon two OGL

rulesets for d100 roleplaying: the Delta Green RPG System (sometimes called the “Misery Engine”)

and the Legend System by Mongoose Publishing. It uses only the open game content parts of those

systems. For details of the Cthulhu Mythos it draws upon OGL material from the Eldritch Tales OSR

game and the Cthuloid Bestiary for OSR Games. This edition only references Mythos entities created

by H.P. Lovecraft and generic horrors – no references to creations by other authors are included,

explicitly or by allusion.

Our purpose in creating the Open Cthulhu HPLed SRD is to provide a fully‐OGL ruleset for

Lovecraftian gaming in common eras and settings. The rules provided here can be used as‐is to

power gritty and deadly games of investigative and cosmic horror. Or, if you are a game designer,

you can use these rules as a platform on which to build your own games. Remix this content

however you wish!

Project Coordinator: Christian T. Rosen ([email protected])

Contributing Writers (new content): David Konrad, Lena Hardaev, Michel Masó, Paul Franzese, Chris

Rosen, Michelle Bernay‐Rogers, and Francis Lim.

The Open Cthulhu HPLed SRD is copyright © 2019, under the Open Gaming License v1.0a

Product Identity: This file contains NO items considered to be Product Identity under the OGL. Everything in the file is Open Content and is thus usable in other games, providing the attached OGL license remains intact.

Contents Introduction ............................................................................................................................................ 1

Structure of this Book ......................................................................................................................... 4

Open Cthulhu Rules (Player Section) ....................................................................................................... 5

Rolling the Dice ................................................................................................................................... 5

What About Miniatures? .................................................................................................................... 5

Investigators ............................................................................................................................................ 5

What Makes an Investigator? ............................................................................................................. 6

Creating an Investigator ...................................................................................................................... 6

Detailed Description: Statistics ........................................................................................................... 8

Detailed Description: Derived Attributes ............................................................................................ 9

Detailed Description: Profession ...................................................................................................... 10

Detailed Description: Allocating Skills ............................................................................................... 12

Detailed Description: Skills................................................................................................................ 13

The Game .............................................................................................................................................. 22

Using Skills ......................................................................................................................................... 23

When to Make Skill Tests .................................................................................................................. 23

Success and Failure ........................................................................................................................... 25

Opposed Tests ................................................................................................................................... 26

Assistance .......................................................................................................................................... 27

Chases ............................................................................................................................................... 27

Improving Skills ................................................................................................................................. 27

Magic Points and Mental Exhaustion ............................................................................................... 28

Combat .................................................................................................................................................. 30

The Combat Round ........................................................................................................................... 30

Attack Rolls........................................................................................................................................ 32

Defense Rolls ..................................................................................................................................... 34

Damage ............................................................................................................................................. 35

Lethality Rating ................................................................................................................................. 37

Protection in Combat ........................................................................................................................ 40

Other Threats to Life and Limb ......................................................................................................... 41

The Aftermath ................................................................................................................................... 44

Sanity ..................................................................................................................................................... 45

Threats to SAN .................................................................................................................................. 45

Insanity and Disorders ...................................................................................................................... 47

Temporary Insanity ........................................................................................................................... 48

Disorders ........................................................................................................................................... 49

Permanent Insanity ........................................................................................................................... 52

Resisting Insanity .............................................................................................................................. 53

Recovering Sanity .............................................................................................................................. 54

Running Open Cthulhu (Keeper Section)............................................................................................... 57

Customizing Open Cthulhu for Different Settings ................................................................................. 57

Step 1: Researching the Setting ........................................................................................................ 57

Step 2: Adjusting the Open Cthulhu Skill List .................................................................................... 57

Step 3: Creating New Professions ..................................................................................................... 59

Step 4: Available Weapons and Technology ..................................................................................... 62

H.P. Lovecraft’s Dreamlands ............................................................................................................. 62

Magic and Tomes .................................................................................................................................. 66

Tomes of the Mythos ........................................................................................................................ 67

Casting Spells .................................................................................................................................... 71

Powers of the Cthulhu Mythos ............................................................................................................. 73

Encountering a Mythos Power .......................................................................................................... 73

Mental Contact with the Infinitely Alien ........................................................................................... 74

Coming Face‐to‐Face with a Living God ............................................................................................ 75

Mythos Powers from Fiction ............................................................................................................. 76

Creatures of the Cthulhu Mythos ......................................................................................................... 79

Other Creatures and Horrors .............................................................................................................. 103

NPCs from Lovecraft’s Fiction ............................................................................................................. 111

Quick NPCs for Open Cthulhu ......................................................................................................... 117

Grimoire of Mythos Spells .................................................................................................................. 119

Spells of Summoning ....................................................................................................................... 119

Spells of Binding .............................................................................................................................. 121

Spells to Contact Mythos Powers ................................................................................................... 122

Spells to Open Conduits to Mythos Powers (Call/Dismiss) ............................................................. 123

Spells of Dimensional Traversal ...................................................................................................... 125

Spells of Warding and Protection ................................................................................................... 127

Miscellaneous Spells ....................................................................................................................... 128

Mythos Artifacts .................................................................................................................................. 131

Open Gaming License v1.0a ................................................................................................................ 133

OPEN CTHULHU HPLED: SYSTEM REFERENCE DOCUMENT (RELEASE 1A)

Page 1

Introduction Remember the days when playing Lovecraftian tabletop roleplaying games meant portraying a

wheezing, neurasthenic professor or lone bookish historian, poking their noses into ancient secrets

that man was never meant to know … with a grisly fate of death and insanity being more likely than

not? With Open Cthulhu you can relive those glorious, simpler days when the only pulp was the

discarded bodies of Shub‐Niggurath’s trampled victims, and where the difference between a narrow

escape and a lifetime locked in Arkham Asylum is a lucky Sanity roll.

The rules you are now reading provide you with everything you need to play games of Lovecraftian

investigative horror. They are derived from a few different sources: some parts of the Open Cthulhu

mechanics come from the Legend RPG (published by Mongoose Publishing), while other elements

come from the Delta Green RPG (published by Arc Dream). The portrayal of the Cthulhu Mythos,

tomes, and the supernatural are partially original to Open Cthulhu.

This game is written from the perspective that you are already somewhat familiar with the idea of

what a tabletop roleplaying game is all about. It also assumes that you already know something

about the Mythos, that clutch of mythological ancient entities described by H.P. Lovecraft in “weird”

tales and novellas – the most famous of which being Cthulhu. If somehow, you’ve found your way to

reading this book without having any prior experience of either tabletop roleplaying or Lovecraft’s

creations, the boxes nearby give you some convenient jumping off points to get you up to speed.

What This Is, and What It Is Not

If you are familiar with OGL games, you will probably already know about System Reference Document (SRDs) created for many other popular tabletop roleplaying games. If you’re not so familiar with the OGL world, the concept may be a little foreign.

A System Reference Document is usually a bare‐bones description of the rules of an open‐licensed roleplaying game, complete enough to understand the game and to create supplements for it, but without the flavor text and illustrations that would be found in a published version of the game. The purpose of SRDs is mostly to provide a reference for other creators who are interested in:

Creating their own games which borrow elements from the SRD, or

Creating supplements to the game described in the SRD.

However, the description of the rules in SRD documents is often detailed enough that someone could use the bare‐bones free versions of the rules and game resources to run the game for a group of players. This is certainly true for the Open Cthulhu HPLed SRD.

<box>What is a Tabletop Roleplaying Game Virtually every book which describes the rules for a roleplaying game includes a short section which

tries to explain what, in fact, the hobby of tabletop roleplaying is all about. While it is certainly

possible that this book represents your first introduction to the wonderful world of roleplaying, it’s

also true that there is a mountain of excellent material out there on the Internet which explains the

principles a lot better than we could here. So, if the whole tabletop roleplaying game format is new

to you, we’d suggest perhaps checking out some of these links:

https://en.wikipedia.org/wiki/Tabletop_role‐playing_game

http://wheelhouseworkshop.com/2016/04/27/what‐exactly‐is‐a‐tabletop‐role‐playing‐

game‐anyway/


Page 2

http://unpossiblejourneys.com/

https://wiki.roll20.net/Introduction_To_Tabletop_RPGs

An even better way to get the hang of what tabletop roleplaying is all about is to see it in action. A

few targeted searches on YouTube will discover a wealth of videos uploaded by gaming groups who

have recorded either audio of their gaming sessions or actual video footage of their group playing. A

couple of good sets of search phrases are:

“actual play cthulhu”

“lovecraft tapes”

“Innsmouth House players ysdc”

Finally, the absolute best way of learning what tabletop roleplaying is about is by playing in a game

yourself. If you have friends who are gamers, or if you are member of a game club which sometimes

plays roleplaying games, asking to get included in a game – whatever genre or rule system – is a

great introduction. This will very quickly give you an appreciation of what the whole thing is about.

</box>

<box>Who was H.P. Lovecraft, and what is the Cthulhu Mythos? Open Cthulhu is based upon the writings of H.P. Lovecraft, a horror author who lived in the early part

of the 20th Century. Although somewhat obscure during his lifetime (and for many decades

afterwards), since the 1980s Lovecraft’s unique style of horror fiction has become remarkably

popular and influential. His influence upon modern horror fiction in general, and the horror sub‐

genre for tabletop RPGs in particular cannot be over‐stated.

Lovecraft and his small circle of 1920s and 1930s writers sought to create an entirely new set of

horrific “creatures,” entirely divorced from the traditional terrors derived from real‐world folklore

(like vampires and werewolves). They did this because, even in their time, they believed that

traditional horrors had become hackneyed and ho‐hum. In later years, the collection of new

monstrosities they dreamed up during the massive game of “collective mythology invention” came

to be called the Cthulhu Mythos, named after one of Lovecraft’s most memorable creations.

Since becoming a hugely influential figure, a massive amount has been written about H.P. Lovecraft

and his creations. Rather than even attempt to summarize his life and art here, the reader is directed

to the following sources:

https://www.hippocampuspress.com/h.p‐lovecraft/about‐hp‐lovecraft/the‐rise‐fall‐and‐

rise‐of‐the‐cthulhu‐mythos

https://www.biography.com/people/hp‐lovecraft‐40102

https://arkhambazaar.com/who‐is‐h‐p‐lovecraft/

All of H.P. Lovecraft’s fiction has fallen into the public domain after having had its copyright lapse.

Thus, it is easy to find copies of his fine tales available for free online, e.g.:

http://www.hplovecraft.com/writings/fiction/


Page 3

For the purposes of Open Cthulhu, there are three important aspects of H.P. Lovecraft’s fiction and

world‐view that shape the types of stories which feature in the game:

1. Nihilistic Cosmic Horror: Lovecraft liked to highlight exactly how insignificant humanity

is in the bigger cosmos. While we think of ourselves as undisputed rulers over our entire

planet, this is more hubris than reality. There are whole vistas beyond our normal sphere

of perception where lurk vastly more powerful entities, few of whom have any reason to

take notice of us (any more than a person would think about the feelings of an ant).

Humanity might be in charge for now, but if any of those other forces decided to usurp

us, they could do so in a heartbeat.

2. Tales of Brooding Investigation and Discovery: Unlike many horror tales of his era,

Lovecraft tried to focus on what we would call “psychological” or maybe even

“philosophical” horror. The scares come not from sudden shocks or moments of gore,

but by slow build up to a revelation which is terrifying because of what it implies as

much as what is actually seen. Accordingly, Lovecraft’s fiction is more about what is

hinted at or implied than what is explicitly shown.

3. Humble, Everyday Protagonists: The main characters in Lovecraft’s fictions aren’t super‐

human heroic types, but humble weedy intellectuals. Physical strength doesn’t help

much when one is facing unstoppable forces from places beyond our understanding, so

the only effective defense is unearthing enough about the true nature of what is

occurring to be able to somehow misdirect or deflect. Of course, understanding the

truth of reality is dangerous, too, so the protagonists in Lovecraft’s tales often pay a

hefty price – sometimes with their very sanity.

</box>

A Small Note on Terminology Most tabletop roleplaying games divide the responsibilities of players. They assume that there is one

player who acts as a “Game Moderator” while everyone else portrays one of the principal characters

in the shared story which the players are collaboratively creating. The moderator’s job is to evoke

the world within which the characters exist, through his or her descriptive words, and also to take on

the roles of minor characters. Open Cthulhu follows this model.

Although most tabletop RPGs follow this pattern, different games use varying terminology to

describe the different player responsibilities. For clarity, here’s how things work in Open Cthulhu:

The player who acts as a “moderator” for the game is termed the Keeper of Forbidden Lore

(usually abbreviated to Keeper).

The characters that are controlled by players are termed Investigators, since much of what

they spend their time doing is uncovering hidden secrets and clues about strange goings‐on.

Other minor characters which the Investigators may interact with are called Non‐Player

Characters (usually abbreviated to NPCs); these characters are portrayed by the Keeper.


Page 4

Structure of this Book The Open Cthulhu rules are divided into two parts – one which describes the rules of the game (for

both players and Keepers), and another which describes some further rules and resources to help

run games (for the Keeper only).

Here’s a quick summary of what is in each part:

Rules Section

How to roll dice;

How to generate Investigator characters;

How to determine whether an Investigator’s actions succeed or fail, based on their skills and

characteristics;

Combat; and

Sanity.

Keeper’s Section

How to customize these rules to a different setting;

Cthulhu Mythos Magic and Tomes;

Powers of the Cthulhu Mythos;

Creatures of the Cthulhu Mythos;

Other Creatures and Horrors to use in your games;

Characters mentioned in Lovecraft’s fiction;

Mythos Spells and Rituals; and

Mythos Artifacts.


Page 5

Open Cthulhu Rules (Player Section) This section describes all the rules that you need to play Open Cthulhu.

In order to play, here’s what you’ll need:

A group of imaginative friends who are keen to play;

A relatively quiet place (physical or virtual) where all the players can easily talk with one

another without too many interruptions;

Some means of taking notes and keeping track of information (like pencil and paper, or

note‐taking software);

Some dice (physical or virtual).

Open Cthulhu uses polyhedral dice common to tabletop role‐playing games: four‐sided, six‐sided,

eight‐sided, ten‐sided, twelve‐sided, and twenty‐sided. The game plays best when you have a few of

each on the table. Or you can find automated dice rollers on the Web and as mobile apps.

Rolling the Dice When the rules need you to roll dice, they use a particular nomenclature to save time and space:

“#D#,” as in “1D8” or “4D6.” The first number is the number of dice. The “D” stands for “dice with

the following number of sides.” The second number is the number of faces on the die. “1D8” means

roll one eight‐sided die. “4D6” means roll four six‐sided dice and add the numbers together.

Sometimes you add or subtract a number from the roll. If it says “1D6+2,” that means roll one six‐

sided die and add two to the result.

Percentile Dice (“1D100”) Actions in Open Cthulhuare resolved using percentile dice. That means you roll 2D10 (two ten‐sided

dice) to get a number from 1 to 100. Before you roll, designate one die as the tens digit and the

other as the ones digit. A zero (0) on the tens die counts as zero except when the ones die is also 0;

then the 0 on the tens die counts as 10. For example:

The tens die comes up “0” and the ones die comes up “3”: 03, or 3.

The tens die comes up “3” and the ones die comes up “0”: 30.

Both dice come up “0”: 100.

The tens die comes up “6” and the ones die comes up “2”: 62.

What About Miniatures? In some tabletop roleplaying games, the exact location and facing of different characters is

important to the tactical flow of the game. This is less true in Open Cthulhu, owing to its focus on

less combat‐oriented action. However, some people still like to use some form of miniature figures

(or buttons, bottle tops, small china albino penguins and the like) to help keep track of where

characters are.

Investigators Before players can begin a game of Open Cthulhu, they must each (apart from the Keeper) create a

character (or Investigator) for themselves. This should probably be done collaboratively as a group

to make sure that a coherent investigative team is generated, and that characters don’t have

irreconcilable differences that would prevent them working together.


Page 6

What Makes an Investigator? All Investigators are composed of four elements:

STATISTICS (“STATS”): Core capabilities for every Investigator. There are eight stats: Strength,

Constitution, Dexterity, Size, Intelligence, Power, Charisma, and Education.

DERIVED ATTRIBUTES: Ratings that indicate physical and mental resilience, derived from stats.

PROFESSION: What your Investigator does for a job, which informs what skills he or she is most

likely to be best at.

SKILLS: What training and education your Investigator has picked up from being taught, or from life

in general.

Creating an Investigator Follow these steps to create a new Investigator or see the box HOW TO CREATE AN INVESTIGATOR

on page 7 for a quick reference.

STEP 1: Determine Statistics Statistics are Strength (STR), Dexterity (DEX), Size (SIZ), Constitution (CON), Intelligence (INT), Power

(POW), Charisma (CHA), and Education (EDU). They range from 3 (the worst) to 18 (the best), with

an average of 10 for an ordinary adult. Statistics represent core capabilities possessed by all

Investigators. All are important. (See DETAILED DESCRIPTION: STATISTICS on page 8).

Statistics are generated as follows:

Roll 3D6 five times, and assign the numbers to STR, CON, DEX, POW, CHA, however you

wish.

Roll 2D6+6 twice, and assign the numbers to INT and SIZ however you wish.

Roll 3D6+3 and assign the number to EDU.

STEP 2: Calculate Derived Attributes The attributes of Hit Points, Magic Points, Sanity Points, and Breaking Point are derived from stats.

They represent physical and mental resilience. When your Investigator is hurt, participates in

magical rituals, exercises mental fortitude, or is traumatized, those scores can drop.

Your Investigator’s Damage Bonus – the amount of additional harm inflicted due to brawn – is also a

derived attribute. (See DETAILED DESCRIPTION: DERIVED ATTRIBUTES on page 9)

STEP 3: Select Profession What does your Investigator do to earn a living? Profession dictates what skills your Investigator is

most likely to have. Each profession has a list of “professional skills” which are likely to be the ones

the Investigator is best at. Some professions’ skill list includes options from which you can select; in

some cases, there are “free slots” into which you can place a skill of your own choosing. (See

DETAILED DESCRIPTION: PROFESSION on page 10)

STEP 4: Calculate and Allocate Skill Points Skills require special training, and come from schooling, experience, or personal interest. Skills are

measured from 0% (no training) to 99% (foremost expert in the world). Each Investigator starts with

a certain base skill rating in each of the skills. This represents the basic chance that any adult human

has at successfully deploying the skill. However, because your Investigator is an experienced person


Page 7

in his or her chosen profession, there is a pool of additional points that you can allocate to increase

the ratings in your professional skills to something higher than these base ratings.

In addition to experience gained through professions, your Investigator has learned things through

everyday living. To represent that fact, a second (smaller) pool of skill points exists which can be

allocated to increase your rating in any skill you wish. (See DETAILED DESCRIPTION: ALLOCATING

SKILLS on page 12)

STEP 5: Add the Final Details Start filling in the details that make your Investigator interesting.

How old is your Investigator? What does he or she look like? What’s his or her nationality?

What’s your Investigator’s name? What are your Investigator’s job and personal life like?

And why, despite all the terrifying dangers, does your Investigator seek to unravel the hidden secrets

of the unseen world?

<box>How To Create An Investigator: A Summary

Steps 1 & 2: Stats & Derived Attributes Roll STATISTIC dice (see page 8) and allocate rolls to Statistics.

Calculate DERIVED ATTRIBUTES (see page 9). o HP = (CON + STR) ÷ 2, rounded up o MP = POW o SAN = POW × 5 o BP = SAN ‐ POW o DB is determined by adding STR+SIZ and consulting the table on page 10.

Calculate commonly‐used stat test values: o Idea = INT × 5 o Luck = POW × 5 o Know = EDU × 5

Steps 3 & 4: Professions & Skills Choose a PROFESSION from the list starting on page 11.

Write down the PROFESSIONAL SKILLS for your Investigator; where the profession includes some options pick which you would like for your Investigator.

Calculate your Investigator’s PROFESSIONAL SKILL POINT POOL. o Pool size equals EDU × 20 percentiles. o Allocate these points to your Professional Skills however you want, adding to the

base chance for the skill (as shown in the table on page 14).

Calculate your Investigator’s NON‐PROFESSIONAL SKILL POINT POOL. o Pool size equals INT × 10 percentiles. o Allocate these to any skill except Cthulhu Mythos. This includes combat skills.

Step 5: Final Details Choose NAME, AGE, and NATIONALITY.

Sketch out as much of your Investigator’s BACKSTORY as you wish.

As you play, your Investigator may develop a MENTAL DISORDER; record the details.

As you play, your Investigator may become ADAPTED to Violence or Helplessness; record the details.

</box>


Page 8

Detailed Description: Statistics Every Investigator has eight core capabilities: Strength, Constitution, Dexterity, Size, Intelligence,

Power, Charisma, and Education. These are the primary building blocks of your character. All

characters and (most) creatures have these same characteristics, which give the basic information

about the character’s physical, mental, and spiritual capabilities.

The definition of each of these is mostly obvious from the names:

Strength (STR): Your Investigator’s raw muscle power, Strength affects the amount of damage he or she deals through physical blows, how much they can lift, push or pull.

Constitution (CON): Constitution measures the health and vitality of an Investigator and helps to determine how much physical damage he or she can sustain. Constitution also determines the Investigator’s general resistance to disease, illnesses, and poison.

Dexterity (DEX): Your character’s physical co‐ordination, agility, suppleness and nimbleness, Dexterity also determines speed of reaction which is important to physical actions and striking ahead of your foes in combat.

Size (SIZ): This is an indication of your character’s mass, and also determines if an Investigator can see over something or fit through a small opening. Size also helps calculate the amount of physical damage an Investigator can sustain and how much damage he or she deals through physical blows.

Intelligence (INT): Your character’s capacity for learning, rationalizing and analysis. It is less a measure of cleverness and more how the Investigator applies what he or she knows either practically or analytically.

Power (POW): A somewhat abstract statistic, Power represents the force of both an Investigator’s soul and their innate magical and spiritual presence. The more Power an Investigator has, the greater his or her force of will, confidence and capacity for magic.

Charisma (CHA): Charisma measures the force of personality. Investigators with a high Charisma have the ability to make friends easily, find themselves the focus of attention when it is needed (and sometimes when not) and persuade others to do things.

Education (EDU): A measure of how much your character has learned in his or her life so far, whether that be through formal instruction or via the “school of hard knocks.” An EDU of 12 is roughly equivalent to a high school education.

An Investigator’s statistics are determined randomly during character generation and are likely to

stay unchanged unless some drastic incident affects the character. The following die rolls are used to

generate statistic values:

Roll 3D6 five times and choose which result will be allocated to which statistics from STR, CON, POW, DEX and CHA.

Roll 2D6+6 twice, and decide which score will be allocated to INT and which to SIZ.

Roll 3D6+3 and assign the number to EDU.

Each statistic (stat) has a test score equal to the stat × 5: STR × 5, INT × 5, POW × 5, etc. This means

roll five times the stat or less on percentile dice (1D100) to succeed.

A few of these test rolls come up more often during play, so shorthand names have been given to

them. These are:

Idea Roll (a short‐hand for INT × 5),

Luck Roll (a short‐hand for POW × 5), and

Knowledge (or Know) Roll (a short‐hand for EDU × 5).


Page 9

When your Investigator attempts a difficult action and no skill covers it, the Keeper may ask you to

roll a stat test for whatever stat is the closest fit.

EXAMPLE: Vanessa wishes to create a new Investigator character for an upcoming game of Open

Cthulhu. She starts by rolling 3D6 five times – she gets 13, 5, 12, 11 and 12. Vanessa decides that she

wants her Investigator to be healthy and nimble and somewhat charismatic. So, she allocates the 13

roll to CHA and the two 12 rolls to CON and DEX. She allocates the 11 to POW which leaves the worst

roll, the 5, for STR (meaning Vanessa’s Investigator will be somewhat of a weakling). Next, she rolls

2D6+6 twice getting 16 and 14. The rough concept in Vanessa’s mind points to a smart Investigator

so she puts the 16 roll to INT and the 14 roll to SIZ. Finally, Vanessa rolls 3D6+3 getting 15. That goes

to her Investigator’s EDU. So, he or she will be quite smart and reasonably well educated but

physically somewhat of a wimp. Already a picture is beginning to emerge. For future reference,

Vanessa pre‐calculates some of the common rolls, jotting down on her character sheet the

Investigator’s Idea (INT×5) will be 80%, Luck (POW×5) will be 55%, and Knowledge Roll (EDU×5) will

be 75%.

Detailed Description: Derived Attributes The derived attributes—Hit Points, Magic Points, Sanity Points, and Breaking Point—represent your

Investigator’s physical and mental toughness. Unlike the core stats, these attributes can and will vary

frequently during play. A fifth derived attribute, Damage Bonus, represents your Investigator’s

enhanced (or diminished) ability to deal damage from hand‐to‐hand attacks based on his or her

brawn.

HIT POINTS (HP): Hit Points represent how much physical damage your Investigator can sustain.

When the Investigator is injured, subtract the damage from HP. At 2 HP, your Investigator falls

unconscious. At 0 HP, your Investigator dies. Hit Points are regained through rest and medical

attention.

Hit Points equal CON plus STR, divided by two and rounded up.

MAGIC POINTS (MP): Magic Points are an abstract representation of mental energy and fortitude. If

your Investigator participates in magical rituals or other supernatural phenomena he or she will

spend these points to fuel the unnatural. Magic Points can also fall when your Investigator becomes

mentally exhausted (see EXHAUSTION on page 29). At 2 MP, your Investigator has a temporary

emotional collapse. At 0 MP, your Investigator falls unconscious. Magic Points are regained with rest.

(See MAGIC POINTS on page 29.)

Magic Points equal POW.

SANITY POINTS (SAN): Sanity Points represent mental health: how much mental trauma, or

exposure to the unnatural your Investigator can endure before going insane. In moments of mental

trauma your Investigator must make a Sanity test by rolling SAN or lower on 1D100. If that fails, your

Investigator loses SAN. (See SANITY on page 45.) Sanity Points are regained through psychiatric care

or by overcoming unnatural threats. At 0 Sanity Points, your Investigator goes irretrievably insane

and becomes an NPC permanently under the control of the Keeper.

Sanity Points begin equal to POW×5.

BREAKING POINT: The Breaking Point is the point at which loss of SAN triggers a long‐term mental

disorder. (See INSANITY AND DISORDERS on page 47.)

An Investigator’s Breaking Point equals SAN minus POW.


Page 10

The instant the Investigator’s SAN reaches the Breaking Point, he or she gains a disorder. Reset the

Breaking Point to equal the new SAN score minus POW.

DAMAGE BONUS: Bigger and stronger combatants are able to hit harder than smaller, weaker ones.

The Damage Bonus is a dice roll that is made in addition to the damage rolled for a weapon. To

calculate the Adventurer’s Damage Modifier, add together the scores for STR and SIZ and look up

the result on the Damage Modifier table.

STR + SIZ Damage Modifier

2‐12 ‐1D6

13‐16 ‐1D4

17‐24 +0

25‐32 +1D4

33‐40 +1D6

41‐56 +2D6

57‐72 +3D6

73‐88 +4D6

Every additional +16 An additional +1D6

EXAMPLE: Vanessa calculates the starting Hit Points for her Investigator by first adding the

character’s CON (12) and STR (5) and dividing the result by 2. Because 17 divided by 2 leaves a

fraction, she rounds up giving her Investigator a HP of 9. Deriving Starting Magic Points is easy, they

are the same as the character’s POW (11). The Investigator’s Starting Sanity Points is simply POW

(11) times 5, or 55. The character’s Breaking Point is that number less his or her POW, or 55‐11 = 44.

Finally, Vanessa adds together the character’s STR (5) and SIZ (14) characteristics and looks up the

resulting total (19) on the Damage Modifier table – that shows her Investigator won’t have a

Damage Bonus, which is hardly surprising given how wimpy he or she is.

Detailed Description: Profession A profession says a lot about an Investigator. It defines a list of skills which the Investigator is more

likely to have at a superior level of proficiency.

The list of professions that are available in your game will depend to some extent upon when and

where the game is set. Hard‐nosed computer hackers might be a staple of a gritty modern or near‐

future game but obviously have no place in a game set in ancient Rome. The list of professions

included here are most appropriate to games set in either the 20th Century or our contemporary

world. If your game is set in a vastly different time or place, the Keeper will likely need to guide the

selection of professions or invent new ones. The box on page 59 provides some guidance on creating

brand new professions.

PROFESSIONAL SKILLS: each profession has a list of skills which are most closely associated with

members of that occupation. These skills will likely make up the core competencies of your

Investigator, so if you want your Investigator to be skilled in a certain area be sure to pick a

profession which includes that skill in its professional skills list. Some professions allow a level of

flexibility in the set of skills which are included – either providing some options from which you can


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choose or providing an “empty slot” into which you can put any skill you wish. You don’t need to

necessarily make a choice at this stage but once you have made a selection you can’t change it later.

A few professions include skills relating to special gear – if the game setting is a time/place where

such gear is uncommon or hasn’t been invented, remove these skills from the professional skill list.

List of Professions

Antiquarian

Professional Skills: Art, Bargain, History, Law, Library Use, Other Language, Spot Hidden + any one

skill as a personal specialty.

Artist

Professional Skills: Art, Fast Talk, History, Psychology, Special Gear (Photography) [if available in

setting], Spot Hidden + any two skills as personal specialties.

Author

Professional Skills: History, Library Use, Other Language, Own Language, Persuade, Psychology + any

two skills as personal specialties.

Clergyman

Professional Skills: Accounting, First Aid, History, Library Use, Listen, Other Language, Persuade,

Psychology.

Journalist

Professional Skills: Fast Talk, Other Language, Own Language, Persuade, Psychology, Special Gear

(Photography) [if available in the game setting] + any two skills as personal specialties.

Lawyer

Professional Skills: Bargain, Credit Rating, Fast Talk, Law, Library Use, Persuade, Psychology + any

one skill as a personal specialty.

Medical Doctor

Professional Skills: Biology, Credit Rating, First Aid, Latin, Medicine, Pharmacy, Psychoanalysis,

Psychology.

Parapsychologist

Professional Skills: Anthropology, History, Library Use, Occult, Other Language, Psychology, Special

Gear (Photography) [if available in the game setting] + any one skill as a personal specialty.

Police Detective

Professional Skills: Bargain, Fast Talk, Law, Persuade, Psychology, Ranged Weapon (Handgun), Spot

Hidden + any one skill as a personal specialty.

Private Investigator

Professional Skills: Bargain, Fast Talk, Law, Locksmith, Psychology, Ranged Weapon (Handgun) +

choose one of the following: Hide, Listen, Martial Arts, Sneak, Special Gear (Photography) [if

available in the game setting], Spot Hidden

Professor

Professional Skills: Credit Rating, Library Use, Other Language, Persuade, Psychology + choose any

two of the following: Anthropology, Archaeology, Astronomy, Biology, Chemistry, Geology,

History, Medicine, Natural History, Physics.


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EXAMPLE: Vanessa has only just finished reading H.P. Lovecraft’s classic tale “The Dunwich Horror”

in which the principal “heroes” are a group of professors and the librarian from Miskatonic

University; accordingly, she decides she would like her Investigator of the Cthulhu Mythos to also be

a Professor. This means she now knows the skills her character is most likely to be good at. The list of

Professional Skills for the Professor occupation allows some degree of selection of personal

specialties – Vanessa chooses two fields of experience from the list, deciding that her Investigator will

be good at Chemistry and History. She thinks perhaps he might be interested in old Alchemical

practices from the Middle Ages, or something similar.

Detailed Description: Allocating Skills Perhaps the most important part of defining your Investigator is selecting the skills at which he or

she will be most proficient. This is a two‐stage process.

1. The first task is to allocate points to your Investigator’s professional skills. Calculate EDU ×

20. This represents the pool of additional skill points you can allocate to skills that are listed

in your profession’s list of “professional skills.” Skills can be increased on a 1‐for‐1 basis (i.e.,

spending 1 point from the pool increases a skill by 1). Don’t forget that most skills start off

with a base rating which everyone gets for free: the points you allocate here are added to

that base.

2. The second task is to allocate a smaller pool of skill points which reflect general abilities your

Investigator has picked up from hobbies or other non‐professional experience. Calculate INT

× 10. Points in this non‐profession‐based pool are allocated in the same way described

above, but can be spent on any skill except Cthulhu Mythos.

It is worthwhile spending some time to allocate points from both pools of skill points carefully. This

is your best chance to shape exactly the areas where your Investigator is most proficient.

EXAMPLE: Vanessa starts the allocation of skill points for her Professor character by calculating the

size of the pool to be distributed. She multiplies the character’s EDU (15) by 20, giving a pool size of

300 percentile points. Based on the list of Professional Skills shown for the Professor occupation, she

has seven skills to distribute those points across. She wants to make her Professor a bit of a research

guru, so Library Use and History will get healthy allocations of points – she puts 40 points towards

each of those. Looking at the base chances for those skills and adding her allocated points she sees

that her Professor will have Library Use skill of 65% and a History skill of 60%. She still has 220 points

to allocate; figuring that she would like her Professor to be good at Latin she puts some points to

Other Language (Latin). Because that skill has a base of 0% she will need to allocate a decent chunk

of her points to make him an expert: Vanessa decides on 70 points. The remaining 150 points she

allocates to Credit Rating (base 15% + allocation of 45 = skill of 60%), Chemistry (base 0% + allocation

of 55 = skill of 55%), Persuade (base 15% + allocation of 30 = skill of 45%), and Psychology (base 5% +

allocation of 20 = skill of 25%). She wishes she could do better for his Psychology skill, but that’s all

the points she has left. That exhausts the pool of skill points based on profession but isn’t the end of

the tale.

Next, Vanessa calculates the size of the general‐purpose (or hobby) skill point pool – that is derived

from her Investigators INT (16) multiplied by 10. That gives her another 160 percentile points which

this time she can allocate to ANY skill. She figures that her Professor is such a weakling that if he or

she ever got into trouble he might be quite short‐lived, so she elects to invest some points in Ranged


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Weapon (Handgun). Checking the skill description, she sees that the character starts with a base of

20% so she spends 35 points from her pool to bump that up to 55% making him or her a reasonable

shot – chances are it’ll come in handy. Vanessa is worried that she ran out of points during the

previous allocation phase leaving her Investigator a bit short on the Psychology skill: she elects now

to spend 20 points from the general‐purpose pool to further bump that skill (base 15% + professional

allocation of 20 + general‐purpose allocation of 20 = skill of 55%). The remaining 105 points she

allocates as follows: Occult (base 5% + allocation of 30 = skill of 35%), Sneak (base 10% + allocation

of 20 = skill of 30%), Spot Hidden (base 25% + allocation of 20 = skill of 45%), Physics (base 0% +

allocation of 30 = skill of 30%). That leaves just 5 points. Vanessa asks whether she can put that into

the Cthulhu Mythos skill, but her Keeper Sam tells her that is not permitted. So instead she puts those

points into Natural History (base 10% + allocation of 5 = skill of 15%).

Detailed Description: Skills While Statistics and Derived Attributes describe a character physically and mentally, Skills describe

what your Investigator can actually do; things he or she has learned, whether intellectual knowledge

or practical skills.

If you make a skill roll, your Investigator is doing something that would leave untrained people lost.

Anyone can attempt a DEX×5 test to keep from falling over in an out‐of‐control Zeppelin; only

someone who’s been trained in the Pilot skill can fly the airship away from the grasping, howling

thing tearing at its gondola.

Roll your Investigator’s skill or lower on 1D100 to succeed at using the skill under dire circumstances.

Skills improve through practice, experience, and training.

Skills with Specializations Some of the skills described below represent a family of related specialized “sub‐skills” grouped

under a common label. For example, the Pilot skill includes sub‐specializations for piloting boats and

others for piloting aircraft. Similarly, the Other Language skill has separate sub‐specializations for

each language that can be written and/or spoken.

Generally, the different specializations of a skill are considered entirely independent – experience in

one confers no particular benefit when a different specialization is called for (e.g., skill in piloting an

aircraft has no bearing on an Investigator’s ability to steer a luxury liner; being able to speak French

doesn’t help when translating a tome written in Arabic).

When allocating points to skills, such skills can be “purchased” multiple times, with each

specialization having the base chance described in the skill description. The development of an

Investigator’s experience in each specialization proceeds independently of any other specializations

of the same skill.

Base Rating Every skill lists its base rating. If a skill has a base rating of 1% or greater, anyone can attempt to use

it. A skill at 0% can’t be used at all. No skill can be higher than 99%.


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Skills and Base Ratings Accounting 10% Anthropology 0% Archaeology 0% Art (specializations) 5% Astronomy 0% Bargain 5% Biology 0% Chemistry 0% Climb 40% Conceal 15% Credit Rating 15% Cthulhu Mythos 0%

Dodge DEX × 2% Drive (spec.) 20% Electrical Repair 10% Fast Talk 5% First Aid 30% Fist/Punch 50%

Geology 0%Grapple 25% Head Butt 10% Hide 10% History 20% Jump 25% Kick 25% Law 5% Library Use 25% Listen 25% Locksmith 0% Martial Arts 0% Mechanical Repair 20% Medicine 5% Melee Weapon (spec.) {varies} Natural History 10% Navigate 10% Occult 5%

Operate Heavy Machinery 0%Other Language (spec) 0%

Own Language EDU × 5% Persuade 15% Pharmacy 0% Physics 0% Pilot (spec.) 0% Psychoanalysis 0% Psychology 5% Ranged Weapon (spec.) {varies} Ride 5% Sneak 10% Special Gear (spec.) 0% Spot Hidden 25% Swim 25% Throw 25% Track 10%

How Skills Work When an Investigator is called on to roll against a skill, he uses 1D100 and is attempting to roll equal

to, or less than, his skill’s value. Achieving this means the skill is used successfully; if the 1D100 roll is

above the skill’s value, then the attempt has failed. Especially low rolls which succeed indicate

superior outcomes, while especially high rolls which fail indicate unusually bad ones.

The Keeper makes skill tests for NPCs, as required.

See USING SKILLS on page 23 for details on when and how to make skill rolls.

Skill Descriptions Accounting [Base Rating 10%]

The study of finance and business. Use it to sift through financial records for anomalies, such as a

hidden bank account or money laundering.

Anthropology [Base Rating 0%]

The study of living human cultures. Use it to understand morals, religious beliefs, customs, and

mores, and to identify (but not translate) obscure languages. Where History is about the distant past

and Archaeology studies physical remains, Anthropology is about the behaviors of living cultures and

how they relate to each other and the past.

Archaeology [Base Rating 0%]

The study of the physical remains of human cultures. Use it to analyze the way of life of a people

from ruins, to determine the age of an artifact, to tell a genuine artifact from a fake, and to identify

(but not translate) human languages. Where Anthropology is about living cultures and History is a

broad study of the past, Archaeology discerns meaning from the remains of peoples long dead.


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Art (specializations) [Base Rating 5%]

Expertise at creating or performing a work that sways emotions and opinions. It also encompasses

knowledge of techniques and trends in your field, and the ability tell a particular creator’s real work

from a fake. Anyone can draw a rough sketch; the Art skill reflects knowledge, practice, and talent.

Each type of Art is a separate skill. Examples include:

Acting, Creative Writing, Dance, Flute, Forgery, Guitar, Painting, Poetry, Scriptwriting,

Sculpture, Singing, Violin, etc.

Astronomy [Base Rating 0%]

Scientific knowledge about the (currently understood) composition of the universe and the Earth’s

place in it. This includes knowledge of celestial bodies and their names, but not the folklore

associated with different constellations and their use in prognostication (instead such understanding

is part of the Occult skill).

Bargain [Base Rating 5%]

This skill is used to secure the best price for goods being either bought or sold and it can be opposed

by another Bargain roll, with the victor securing the advantage. Bargaining is more than just

haggling; it is concerned with negotiation, compromise, brinksmanship and knowledge of the

strength (or weakness) of the market for what is being traded. Where highly complex commercial

deals are being discussed, a succession of opposed Bargain rolls might be called for, with cumulative

bonuses or penalties loser, simulating the ebb and flow of the negotiation before settlement is

reached.

Biology [Base Rating 0%]

Knowledge of the life science of Biology, as understood in the era in which the game is set. This

includes a technical understanding of known living organisms of the plant and animal kingdoms.

Chemistry [Base Rating 0%]

Scientific knowledge pertaining to the substances from which the natural world is composed, and

the ways in which they react with one another.

Climb [Base Rating 40%]

Use the Climb skill to scale vertical surfaces, either with or without equipment. If the Investigator

needs to scale a surface silently, successful rolls against both this skill and the Sneak skill are

required.

Conceal [Base Rating 15%]

This skill is used to cover up or obfuscate the location of an item or object. It doesn’t allow the

Investigator to conceal his or her self – for that, the Hide skill is needed.

Credit Rating [Base Rating 15%]

A general measure of an Investigator’s financially prosperity. In many situations this will equate to

social standing. The skill can be used as a means of obtaining a loan or a line of credit. Events that

occur during play may impact upon the Investigator’s perceived position in the social ranks and in

turn lead to increases or decreases in Credit Rating.


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Cthulhu Mythos [Base Rating 0%]

Knowledge of the fundamental, mind‐rending secrets of the universe. Use it to remember,

recognize, or research facts about the things that humans consider unnatural. This goes far beyond

the occult, because the Cthulhu Mythos skill represents things that are real. Use it to sift through the

darkest parts of myth and folklore and recognize which of it is true. Your Investigator’s SAN score

can never be higher than 99 minus his or her Cthulhu Mythos skill rating.

Dodge [Base Rating DEX × 2%]

The Dodge skill is used to escape from impending danger and can be used to avoid objects or

weapons that are swung or thrown at the character (and in some cases fired from ranged weapons.

The skill can also be used for generally getting out of the way of a potential physical hazard. For its

use in conflict, see the Combat chapter (starting on page 30) for more information.

Drive (specializations) [Base Rating 20%]

The Drive ability allows control over a land‐based vehicle. If a character is driving at a safe pace

across flat terrain, a Drive test will never be required. Tests become required when a character

wants to do something out of the ordinary with a vehicle – traverse treacherous terrain, jump

obstacles and so on.

Note that Drive does not cover the control of air‐ or water‐based vehicles; those are covered by the

Pilot skill.

Depending on the technology available in the game setting, Drive skill specializations might include

some, or all, of the following:

Drive Horse & Cart (for pre‐industrial settings),

Drive Carriage / Coach (for early Industrial settings)

Drive Automobile (for 20th Century and later),

Drive Motorcycle (for 20th Century and later), or

Drive Hovercar (for future settings).

Electrical Repair [Base Rating 10%]

The ability to fix devices which function according to simple electrical principles; this includes

domestic electrical appliances and automobile engines. If the problem relates to more sophisticated

forms of electronics, this skill is of limited use – the Special Gear (Electronics) skill is much more

helpful.

Fast Talk [Base Rating 5%]

The art of bamboozling somebody into agreeing with your point of view, usually through rapid and

unrelenting statements. This technique can be helpful at tricking someone into agreeing with a point

of view for a brief time, although eventually the person will realize they have been duped. For a

more permanent alteration of someone else’s opinion, the Persuade skill is needed.


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First Aid [Base Rating 30%]

The initial treatment and stabilization of injuries. Use it to help a character recover lost Hit Points. By

comparison, Medicine corrects a severe wound and ensures long‐term recovery. (See HEALING on

page 36.)

Fist/Punch [Base Rating 50%]

An unarmed combat skill, reflecting your Investigator’s ability to inflict damage with his or her fists.

Normally, such attacks will do 1D3 damage plus the character’s Damage Bonus.

Geology [Base Rating 0%]

Scientific knowledge about the physical structure of the earth, its history, and composition. This skill

provides the Investigator with an understanding of the topic as it is understood in the era where the

game is set.

Grapple [Base Rating 25%]

The Grapple skill is used in unarmed combat situations where the attacker’s primary intention isn’t

to inflict harm, but to subdue or incapacitate a foe (or fend off someone who is trying to inflict a

similar fate upon the character).

There are several different ways of using the skill, see the action types described in THE COMBAT

ROUND starting on page 30 (in particular, the DISARM, ESCAPE, and PIN actions).

Head Butt [Base Rating 10%]

A style of unarmed combat, much favored in bar‐room brawls across history. Normally such attacks

will inflict 1D4 damage plus the character’s Damage Bonus.

Hide [Base Rating 10%]

This skill is used to obscure the Investigator’s location to deceive a pursuer into not detecting his or

her presence. This is different to the Conceal skill which is used to secrete objects to avoid their

identification.

History [Base Rating 20%]

Uncovering facts and theories about human antiquity. Use it to remember or find a key fact about

the distant past, recognize an obscure reference, or comb a database or library for information that

nobody without your deep education could find. While Anthropology is about living cultures and

Archaeology studies the meaning of ancient relics, History is a broad study of humanity.

Jump [Base Rating 25%]

This skill covers the athletic ability to safely jump upwards or downwards to reach a desirable

vantage or to avoid a damaging fall.

Kick [Base Rating 25%]

The unsubtle art of unarmed combat with one’s feet. Normally such attacks will inflict 1D6 damage

plus the character’s Damage Bonus.


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Law [Base Rating 5%]

Using laws and courts to your Investigator’s advantage. Use it to get your Investigator’s way in court,

to determine the correct procedures for handling evidence in a prosecution or a civil case (and how

to undermine them), to bluff your Investigator’s way out of legal trouble, or to minimize legal risks.

The Law skill applies to your Investigator’s native country or community; using it in other

jurisdictions may not be possible or may incur a penalty (Keeper’s call).

Library Use [Base Rating 25%]

The ability to find specific information in a large repository. This can be a very important to

investigations that involve a significant amount of research. Your Investigator can employ his or her

Library Use skill to track down obscure texts using a library’s card catalogue, sift relevant details

from a newspaper’s clipping morgue, or (in modern‐ or future‐era games) locate obscure sites on the

Dark Web with the hard‐to‐find information suppressed by authorities.

Listen [Base Rating 25%]

The ability to perceive and understand audible sounds. This can include picking up extremely faint

background noises through a thick door, or overhearing conversations across a noisy ballroom. It can

also include the ability to discern one sound from a similar but distinct copy.

Locksmith [Base Rating 0%]

Using a range of mechanical means to bypass locks, create new keys, or even repair broken locking

apparatus. Sophisticated locks such as those found in safes or bank vaults may require additional

specialist equipment and experience, in addition to successful deployment of this skill. Electronic

locks may require a combination of this skill and either Electrical Repair or Special Gear (Electronics).

Martial Arts [Base Rating 0%]

This skill allows an experienced Martial Artists to make unarmed hand‐to‐hand attacks which inflict

more damage than usual. Prior to making an attack using Fist/Punch, Head Butt, Grapple, or Kick,

declare that the attack will employ Martial Arts technique. Make a single percentile roll: if the roll is

a success AND below your skill rating in Martial Arts, the attack will inflict twice the normal amount

of damage (e.g., a Fist/Punch attack deals 2D3 damage). If the attack was a success but the roll is

above the Martial Arts still rating, only normal damage is dealt. Note that the doubling of damage

occurs BEFORE the damage bonus is applied.

Mechanical Repair [Base Rating 20%]

The tradesman’s ability to fix broken machinery and other mechanical apparatus. Complex tasks are

likely to require access to tools and materials. Note that this skill does not explicitly cover the

manipulation of locks – that is Locksmith – however, the Keeper may decide in certain situations, a

lock may also be susceptible to a particularly good Mechanical Repair roll.

Medicine [Base Rating 5%]

The study and treatment of injury and illness. Use it to diagnose the cause of an injury, disease, or

poisoning, identify abnormalities such as toxins or diseases, identify the cause and approximate time

of death, identify the type of weapon used to kill a victim, identify a dead person’s last meal, or

prescribe proper long‐term care. By comparison, First Aid keeps a patient alive until surgery is

possible. (See HEALING on page 36).


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Melee Weapon (specializations) [Base Rating varies by weapon type]

The Melee Weapon skill is the ability to wield weapons which do damage up close, usually as part of

hand‐to‐hand combat. Use it to hurt or kill an opponent with a knife, axe, club, baseball bat, or other

similar weapon. Depending on the technology available in the setting this might mean primitive

weapons like sticks and spears or more complex weapons such as swords. Each type of melee

weapon represents a separate skill, thus Melee Weapon (Club) is entirely separate to Melee Weapon

(Knife) and must be purchased separately.

Depending on the types of technology in common use in the game setting, some or all of the

following specializations may be appropriate:

Melee Weapon (Axe) [Base Rating 20%]

Melee Weapon (Knife) [Base Rating 25%]

Melee Weapon (Sword) [Base Rating 15%]

Melee Weapon (Club) [Base Rating 25%]

Natural History [Base Rating 10%]

The common understanding of the natural world as practiced by outdoorsmen, farmers, fishermen,

and others who make a living based upon the changing patterns of the weather, tides, etc. It also

covers the broad understanding of the natural habits of animals, as well as the different uses of

specific plant species. Use this skill to determine whether observed behavior of natural forces or

creatures is consistent with “normal” or common patterns, or not.

Navigate [Base Rating 10%]

Finding your way quickly with maps, charts and tables, orienteering, instruments, or dead reckoning.

Occult [Base Rating 5%]

The study of the supernatural as understood by human traditions, including things like conspiracy

theories, fringe science, and cryptozoology. Use Occult to examine and deduce the intent of a ritual,

or to identify occult traditions, groups, grimoires, tools, symbols, or legends. Occult can never tell an

Investigator what’s genuinely unnatural and what’s just superstition or mythology. That’s the

province of the Cthulhu Mythos skill.

Operate Heavy Machinery [Base Rating 0%]

Safe operation of a large piece of industrial machinery – depending on the technology available in

the setting this could be a tractor, crane, bulldozer, tank, heavy thresher, or another big machine. A

skill roll is usually only required when attempting to operate the device in a crisis.

Other Language (specializations) [Base Rating 0%]

The Other Language skill is actually several separate skills grouped under a single heading. Other

Language (English), Other Language (German) and Other Language (French) are all individual skills.

Every character with a Language skill of 50% or more is fluent in that language, though they will

likely bear an accent if it is not their native language.

Investigators with an Other Language skill of 80% or more can also freely read and write in that

language.


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Own Language [Base Rating EDU × 5%]

The Investigator’s proficiency in his or her native language. This skill is not needed to read or write

simple passages but may become important when deciphering complex or outmoded forms of

written text. It might also become important when using language in a difficult or stressful situation

where the consequences of failure are significant.

Persuade [Base Rating 15%]

Changing another’s deeply‐held decision or desire. Use Persuade to get your Investigator’s way

when the subject is so stubborn, what your Investigator wants is so valuable, or the deception is so

flagrant that CHA isn’t enough. With Persuade, your Investigator might convince a witness that what

she saw was innocuous and not unnatural, talk a detective into helping you cover up evidence for

the greater good, or draw useful information out of an unwilling subject. This skill also allows your

Investigator to resist persuasion and interrogation in opposed Persuade rolls (see OPPOSED TESTS

on page 26).

Pharmacy [Base Rating 0%]

Knowledge of drugs, from their ingredients and creation, to their effects, uses, and misuses. Use it to

identify and produce medicines and antidotes—as well as poisons. Identifying a drug requires at

least 20% skill. Preparing a particularly powerful drug safely, such as one with psychoactive effects,

requires at least 40% skill or a successful roll. Misusing Pharmacy is a quick way to kill a patient (see

POISON AND DISEASE on page 41).

Physics [Base Rating 0%]

Scientific knowledge about the physical world, and in particular the actions of forces, optics,

radioactivity, and the theoretical foundations of electricity and electronics. The skill doesn’t

necessary grant a hands‐on understanding of any of these disciplines, but does provide a sound

grasp of the underlying laws, theorems, and principles at play.

Pilot (specializations) [Base Rating 0%]

Piloting, navigating, and captaining waterborne, airborne, or spaceborne vehicles (where such

technology exists in the setting). Use it to keep a vessel safe in a crisis, such as through a storm or in

a dangerous pursuit. Each vessel type is a separate skill.

Psychoanalysis [Base Rating 0%]

The diagnosis and treatment of mental illness. Use it to identify a mental disorder, help a patient

recover, talk someone down when a disorder begins to take over, and treat mental illness in the long

term. You cannot use Psychoanalysis on yourself. Using Psychoanalysis to aid someone who suffered

exposure to Cthulhu Mythos forces might cost the therapist SAN; see THREATS TO SAN on page 45.

Note that in settings where there is no clinical practice of psychoanalysis or psychotherapy, this skill

still exists but takes on a different interpretation, namely the timeless art of healing a shattered

mind through empathy and folk remedies.

Psychology [Base Rating 5%]

The understanding of the human psyche, in all its myriad forms. Use this skill to detect whether

someone is lying to your Investigator, or otherwise attempting to conceal their motives. Or use it to

spot the tell‐tale signs of stress and nervous tension or see the subtle signs of a shift in an


Page 21

individual’s allegiances. While players may request a roll against their Investigator’s Psychology skill,

the Keeper can elect to make the roll on their behalf, in secret.

Ranged Weapon (specializations) [Base Rating varies by weapon type]

The Ranged Weapon skill is the ability to wield weapons which do damage at a distance. Depending

on the technology available in the setting this might mean firearms or lower‐technology ranged

weapons such as throwing slings, knives, crossbows (or both). Each type of ranged weapon

represents a separate skill, thus Ranged Weapon (Handgun) is entirely separate to Ranged Weapon

(Bows) and must be purchased separately.

Depending on the types of technology in common use in the game setting, some or all of the

following specializations may be appropriate:

Ranged Weapon (Bow/Crossbow) [Base Rating 20%]

Ranged Weapon (Handgun) [Base Rating 20%]

Ranged Weapon (Rifle) [Base Rating 25%]

Ranged Weapon (Shotgun) [Base Rating 30%]

Ranged Weapon (Sub‐machine gun) [Base Rating 15%]

Note that ranged weapons that are thrown by the attacker (e.g., spears, throwing knives, or

boomerangs) are not covered under a Ranged Weapon skill but instead use the Throw skill to

determine whether the weapon hits its desired target.

Ride [Base Rating 5%]

This skill is used for riding an animal such as a horse, mule, or donkey. If a character is riding a

creature with the help of saddle and stirrups, at not more than a walking pace across flat terrain, a

Riding test will never be required. Tests become required when a character wants to do something

out of the ordinary with a mount – traverse treacherous terrain, jump obstacles, ride bareback and

so on.

Sneak [Base Rating 10%]

The Sneak skill is used whenever a character attempts to personally evade detection by another

character or surveillance equipment. This usually happens when a character either tries to move

quietly past an enemy, hide from one or perform a combination of both. Sneak tests are sometimes

opposed by the Spot Hidden skill and are modified according to the situation.

Special Gear (specializations) [Base Rating 0%]

Nobody needs to make a skill roll to use devices and technologies that are in common use in the era

and setting of the game. However, making effective use of highly‐specialized or technical apparatus

is a different question. In the hands on the untrained, such devices are at best useless, and at worst

dangerous. Special Gear is an umbrella skill with different specializations covering various categories

of technical devices.

The types of devices available to Investigators will vary depending on when and where the game is

set. The following are examples:

For games set after ~1850, the skill Special Gear (Photography) allows an Investigator to

take, develop, and print high quality photographic images using any available technology

(still or motion). It can also be used to enhance photographs or moving images.


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For games set in the 1980s or later, the skill Special Gear (Computers) permits an

Investigator to build, repair, and program all forms of computing equipment. The day‐to‐day

use of a computer to browse the Internet or write a letter requires no skill roll, but complex

tasks like bypassing security features of operating systems certainly will.

For games set in the 1950s or later, the skill Special Gear (Electronics) allows an Investigator

to build and repair electronic devices, given access to the correct components and tools.

This differs from Electrical Repair, which focusses on equipment that uses electricity directly

but does not employ complex techniques like circuit boards or microchips.

Spot Hidden [Base Rating 25%]

The Spot Hidden skill is used to represent the senses of the character when detecting objects or

other characters. It covers such situations as detecting someone creeping about in the next room,

trying to spot Cultists moving on a distant hillside, or searching a house for a hidden room.

Sometimes it will be opposed by another skill, such as Sneak. A successful Spot Hidden roll can

sometimes be crucial in preventing a group of Investigators being ambushed by enemy forces.

Swim [Base Rating 25%]

Most Investigators can swim for leisure. Use the Swim skill in a dangerous crisis: going a long

distance in choppy water, keeping a friend from drowning, or getting to a boat before the tentacled

thing below grabs your legs.

Throw [Base Rating 25%]

The ability to accurately throw an object with force. Use it to land a rock or shotput in a precise pre‐

determined spot (e.g., a windowpane). Or use it as a combat skill for weapons such as spears and

throwing knives.

Track [Base Rating 10%]

With this skill an Investigator can locate the tracks (footprints, disturbed vegetation and so on) of a

specific creature and follow them. A test must be made to locate the trail and then again once every

hour they are being followed. Modifiers will be imposed depending on what terrain the trail is

across, how long ago the tracks were made and whether anything has been done to cover them

(either deliberately or via the weather).

The Game Open Cthulhu is a game about normal, everyday people who are confronted with hidden truths

about the horrors which lurk unseen throughout our world. By fighting to keep the ancient and alien

terrors from gaining a foothold, they might keep humanity safe … for now.

It is not a game about heroic, larger‐than‐life battles against comic‐book or silver‐screen villains;

players seeking such two‐fisted pulp action might be best served by tracking down one of any

number of existing roleplaying games which specifically cater to such storytelling.

The fate of Investigators in Open Cthulhu is inherently uncertain. The ancient and hidden forces

against which they battle are both terrifyingly powerful and dangerously unknowable. Many of those

who venture into the dark and haunted places where they lurk, do not return at all – or return as

insane husks of their former selves. And yet, despite this almost hopeless task, it is ultimately the


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deeds of people like the Investigators who represent the only real opportunities for curbing the

inevitable rise of Cthulhu and his ilk.

When you look at it like that, even a bookish octogenarian professor just might be considered a

“hero” if his sacrifice holds back the extradimensional forces for another day.

That is the fight which keeps Open Cthulhu Investigators going. And it is what the game is all about.

Using Skills The Open Cthulhu system focuses on skills. For most actions that you want your Investigator to

undertake, the resolution is the same: you describe what you wish to achieve, and in collaboration

with the Keeper determine which skill best applies. You then roll a 1D100 and compare the roll to

your Investigator’s current rating in that skill. This is called a skill test.

When to Make Skill Tests Not all actions performed by an Investigator require a skill test. For example, a skilled Linguist who

uses his or her Other Language (Latin) skill every day to translate the everyday correspondence of

Roman scholars can likely decipher Miskatonic University’s Latin motto without blinking. However, if

faced with a cryptic and antique Latin manuscript written in an obscure dialect, he or she will almost

certainly need to draw upon all reserves of knowledge (represented by a skill roll). Skill Tests are

required where the circumstances are out of the ordinary and/or impart some degree of stress,

urgency or difficulty to the situation.

In general, the following guidelines can be followed to determine whether an action requires a skill

roll or not:

If the outcome of the action is in doubt, make a skill roll – since the character is pushing the

boundaries of his or her knowledge or experience, and may fail.

If there is a level of tension or drama, make a skill roll – since the situation constitutes a

point in the game where the stakes are high, and a level of uncertainty might enhance the

sense of drama. This shouldn’t be over‐used, however, or the dramatic effect will quickly

diminish.

If the character is being forced to perform the action under duress or haste – since most

day‐to‐day application of skill relies on ample time and a lack of pressure, performing in a

“pressure cooker” environment is far more prone to failure. For this reason, most actions

undertaken within combat will require some kind of roll.

Conversely:

If the situation would be better resolved through role‐playing or storytelling, don’t make a

skill roll – since the narrative flow of the game will probably produce a more satisfying

outcome for both players and Keepers.

If the situation is routine, or similar to something that has occurred recently, don’t make a

skill roll – since it is usually better to either allow routine attempts to automatically succeed

or bundle several smaller challenges into a single skill roll.

If there is no dramatic consequence to failure, don’t make a skill roll – since rolling for the

sake of it only serves to break player immersion in the game.


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What If You Don’t Have any Rating in the Skill? If your Investigator has a rating 0 in a skill, he or she can’t even attempt to use it. It requires

specialized training or education that your Investigator lacks.

What If No Skill Applies to the Situation? If your Investigator tries to do something that anyone ought to be able to do—something that is

hard but doesn’t require specific training like a skill—then the Keeper might look to one of your

Investigator’s stats, for a stat test. A stat test is the relevant stat × 5. (So, with STR 11, a STR test is an

attempt to roll under 55% on a 1D100.)

Use STR if the challenge requires physical power, CON if it requires endurance or healthiness, DEX if

it requires agility, INT if it requires attention to detail or mental gymnastics, POW if it requires

mental or spiritual resilience, or CHA if it requires charm.

Some stat tests come up more frequently than others in normal play, and so have a short‐hand

name to refer to them:

An Idea Roll is INT × 5: use it when your Investigator is called upon to solve an intellectual

problem which is amenable to raw brain‐power but doesn’t necessarily require any

specialized training or skill.

A Knowledge (or Know) Roll is EDU × 5: use it when your Investigator is called upon to recall

some item of general knowledge that does not fall into the specialized domain of any skill.

A Luck Roll is POW × 5: use it in situations where your Investigator is relying on the inherent

goodwill deriving from his or her indefinable relationship with the Universe. Some people

are inherently luckier than others and seemingly random events will tip in their favor more

often than statistics would predict.

Skill Roll and Stat Roll Difficulty Circumstances can make a skill easier or harder to accomplish. For example, driving an automobile

to out‐pace a Flying Polyp requires a Drive Skill Test but if the chase is occurring off‐road across a

plain of jagged rocks, the circumstances are harder than normal: the skill’s value is therefore

modified to reflect this. Conversely hiding from a Deep One in a dark wood as night sets in, requires

a Hide Skill Test but the darkness makes hiding easier and so the skill’s value is modified accordingly.

Circumstances are graded in the Difficulty table. These modifiers are applied temporarily to the

skill’s value until the circumstances change.

Difficulty Modified Stat Roll Modified Skill Roll

Very Easy Roll under Stat × 10 Roll under Skill × 5

Easy Roll under Stat × 7 Roll under Skill × 2

Normal Roll under Stat × 5 Roll under Skill

Hard Roll under Stat × 3 Roll under Skill ÷ 2

Very Hard Roll under Stat × 1 Roll under Skill ÷ 5

EXAMPLE: Vanessa’s newly‐created Professor, who she has named Walter Mason, is investigating

the mysterious disappearance of an ancient Etruscan artifact from a locked room at the local library.

He is closely inspecting the plinth on which the weird stone idol once stood. The Keeper asks Vanessa

to make a normal Spot Hidden roll to see if Walter notices anything interesting. During character

generation, Vanessa spent some points to buy percentiles in Spot Hidden, so Walter has a


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respectable rating of 45%. Vanessa rolls a 1D100 and gets a 27 – under the skill rating of 45, so

Walter succeeds in the skill test. The Keeper, Sam, tells Vanessa that Walter has spotted some tiny

grooves in the pedestal that look almost like shallow cuts made by a knife or claws. None of the other

displays have similar markings. Vanessa asks whether Walter could pick up the plinth to take away to

show his colleagues. The Keeper says that would probably be a Hard test of the STR stat. That means

Vanessa would need to roll a 1D100 under Walter’s STR × 3 (or 15%). That doesn’t seem very likely.

But before Vanessa can decide whether she wants to try, Walter is distracted by a strangely‐dressed

man who bursts into the room … and quickly runs out the building’s main exit, slamming the door

shut behind him.

Success and Failure On any skill or stat test, there are only four possible outcomes. From best to worst they are: Critical

Success, Success, Failure, and Fumble. Ordinary success and failure are most common. Critical

successes and fumbles represent exceptionally good or terrible outcomes.

Critical Successes For many Skill Tests it is only necessary to determine whether one is successful or not. However,

there may be certain cases where it is important to know how successful an Investigator was – did

he or she just skim by or somehow achieve an incredible feat?

If the Skill Test is equal to or less than one‐fifth of the modified skill (rounded up), then the

Investigator has scored a critical success (e.g. A character with 70% in a skill would get a critical

success on a roll of 14 or less – remember, always round fractions to the nearest whole number).

A roll of 01 is always a critical success.

The actual result of a critical success varies from skill‐to‐skill and is largely up to the Keeper. It

normally achieves one of the following results:

The task is completed sooner.

The task is completed to a higher degree of expertise than normal.

The task is completed with élan and style, generally impressing witnesses.

The character gains additional information or insight into the task, thanks to their brilliance.

Special rules apply to Critical Successes during combat – see the relevant chapter for details.

Normal Successes A normal success is a roll equal to or less than the test chance, but not below the threshold for a

critical success (see above). With a success, your Investigator accomplishes what he or she set out to

achieve.

Failures A failure is a roll that’s higher than the test chance but not 00. Sometimes that means your

Investigator suffers harm.

There may be times when a failed roll means an Investigator achieves what he or she wanted—but it

comes with an unpleasant complication. The Keeper always decides whether that’s the case and

what the cost will be.

Fumbles If one can succeed critically, one can also fail critically: a situation known as a fumble. A fumble

occurs whenever a roll for a skill of stat test is 00 (even if the skill or statistic is above 100).


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The precise effects of a fumble depend on the skill and is largely up to the Keeper to decide. It

normally results in one of the following mishaps:

The task takes twice as long to finish and is still a failure.

The task produces a useless result, which actually makes further actions more difficult.

The task is failed spectacularly, opening the character up to derision and scorn from witnesses.

The character becomes impeded or even harmed by his failure.

Fumbles during combat can be especially dangerous – see the relevant chapter for details.

Opposed Tests There are occasions when your Investigator’s actions will be in direct opposition or competition with

another character, or an object in the game world. Such situations call for a special kind of test called

an opposed test. In an opposed test both participants roll against their respective skills/statistics.

The winner of the test is the one who gains the higher level of success; if both participants have the

same level of success, then the winner is the one with the higher dice roll within his skill range.

The table below summarizes the possible outcomes:

Opponent Succeeds Opponent Fails

You Succeed (normal or critical success)

A critical success beats a success. Otherwise, whoever rolled higher succeeds and the other fails.

Your action succeeds, and the opponent’s action fails.

You Fail or Fumble You fail to stop the opponent’s action or reaction.

Nobody succeeds.

There are three common types of opposed tests, and one less‐common type:

1. Opposed Tests which compare a skill vs a skill, both on the scale 0—100 (e.g., pitting a

lurking character’s Hide skill versus a searching character’s Spot Hidden skill).

These are resolved by the player rolling a d100 against the Investigator’s skill; the Keeper rolling a d100 against the adversary’s skill and comparing on the table

2. Opposed Tests which compare a statistic vs a statistic or derived attribute, both on the

scale 0—20 (e.g., pitting an investigator’s POW against a cult leader’s POW during a psychic

battle of wills).

These are resolved by the player rolling a d100 against the Investigator’s statistic × 5; the Keeper rolling a d100 against the adversary’s statistic × 5 and comparing on the table

3. Opposed Tests which compare a statistic vs a fixed number, both on the scale 0—20 (e.g.,

pitting an Investigator’s STR against a door’s STR of 14, during an attempt to break it down).

These are resolved by the player rolling a d100 against the Investigator’s statistic × 5; the Keeper rolling a d100 against the fixed number × 5 and comparing on the table

4. [Less common] Opposed Tests which compare a skill versus a characteristic, the former on

the scale 0—100 the latter on the scale 0—20 (e.g., pitting an Investigator’s Psychology skill

against a sorcerer’s POW during an attempt to see past a deceptive glamor)

These are resolved by the player rolling a d100 against the Investigator’s skill; the Keeper rolling a d100 against the adversary’s statistic × 1 and comparing on the table


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Assistance Investigators often have the opportunity to help one another during various tests. The Keeper is the

final judge as to which tests can be helped with assistance and which require an Investigator to

make the test alone. When multiple characters are working together, one person (usually the one

with highest relevant skill) is the primary character, and the others are assisting characters. Every

assisting character adds one‐tenth of his or her skill to the primary character’s skill, and the primary

character then rolls to see if the project was successful.

The Keeper should bear in mind the practical limitations of the situation to decide the maximum

number of characters that can usefully participate (e.g., a normal‐sized door may only be large

enough for two or three characters to simultaneously attempt to kick it down).

Chases Your Investigator may end up in a pursuit situation where he or she is trying to flee or catch another

character. Pursuits are handled as a series of Opposed Tests. The most basic chase is a single test for

each side, pursuer and quarry. If the quarry wins, he or she escapes and the chase ends. If the

pursuer wins, he or she (or it) runs the quarry down and the chase ends. Often that means combat.

A more prolonged chase may require two wins by one side or the other. Wins cancel each other out.

If the pursuer wins one but the quarry wins the next, that cancels out the pursuer’s win. Then, the

quarry needs to win twice more to escape. An especially wide‐open chase might require three wins

to either catch up or escape.

In each test, one side or the other wins. If both fail their rolls, the lowest failure wins. A critical

success with a chase test counts as two wins. A fumble counts as two failures thanks to a trip, a

wreck, or some other disastrous accident.

WHICH SKILL APPLIES IN A CHASE: A chase on foot requires DEX (or CON for situations where

exhaustion is a factor); one in vehicles uses Drive, Pilot, or even Operate Heavy Machinery; in the

water, use Swim; on horseback, use the Ride skill.

EXAMPLE: Professor Walter Mason is pursuing the man he saw fleeing from the library. The Keeper

tells Vanessa that the foot chase will be handled as a series of several opposed tests pitting Walter’s

DEX × 5 (60) against the shambling figure’s DEX × 5 (50) until one side achieves two “wins”. For the

first segment of the chase, Vanessa rolls a 45, which is a success and his quarry also rolls a success.

So, the man does not escape but neither does Walter close on him. For the second segment, Vanessa

rolls very well getting an 06 on the 1D100 roll – that constitutes a critical success, counting as two

“wins”. Her quarry botches the roll entirely, rolling over his DEX × 5. Overall for the round that means

Walter scored two wins and has caught up with the man just as the two reach the front steps of a

strange “alternative religion” church called the Temple of the New Light. The shabby man curses and

dives inside but has no time to stop Walter following.

Improving Skills If your Investigator successfully makes use of one of his or her skills during the course of an

adventure, there is a chance that the experience has taught something new. It is through such

successes that Investigators can improve their skill ratings.


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During play, each time you make a successful skill roll place a check mark next to the skill to record

the fact. At the end of the scenario (or at some suitable period of “downtime” nominated by the

Keeper) you can attempt to improve the skill rating for all skills marked with a check mark. Note that

it doesn’t matter whether the skill was used one time successfully in the scenario or a hundred

times, your Investigator still only gets one chance to improve the skill.

Skill improvement checks are made by rolling 1D100 and attempting to roll OVER the current skill

rating. If that occurs the relevant skill rating is increased by 1D10 percentiles and the check mark

against that skill is erased. If the roll is equal to or less than the current skill rating, the Investigator

has learned nothing – erase the check mark and move on to making improvement rolls for other

skills. Continue this process until all check marks have been erased.

IMPORTANT NOTE: The Cthulhu Mythos skill cannot be improved through normal skill

improvement. It is only possible to gain skill rating points in Cthulhu Mythos through interactions

with creatures of the Mythos or by studying tomes written about them.

Improving A Skill Rating Beyond 90% If an Investigator manages to increase his or her rating in a skill to the point where it is at 90% or

more, he or she receives a one‐time reward of 2D6 Sanity Points. This reflects the sense of

achievement and mastery that comes with such an achievement. Next time the skill increases there

is no reward.

Magic Points and Mental Exhaustion An Investigator’s Magic Points are an abstraction of his or her mental energy – they are the fuel

which keeps the Investigator’s mind going. Like Hit Points, the Investigator’s totals will go up and

down during play. They are called Magic Points because this mental energy can also be channeled

into the casting of magical rituals or spells, if the Investigator knows the correct techniques.

An Investigator’s Magic Points are also important to resisting unwanted persuasion, and generally

avoiding the consequences of mental exhaustion.

LOW MAGIC POINTS: An Investigator whose Magic Point total hits 1 or 2 has an emotional

breakdown. The Investigator suffers a penalty to all actions, halving all skill, stat and Sanity tests

until Magic Point total rises above 2.

RUNNING OUT OF MAGIC POINTS: An Investigator whose Magic Point total hits 0 collapses,

completely incapacitated and perhaps unconscious. The Keeper controls your Investigator until

Magic Points return to 1 or higher. An Investigator with 0 Magic Points cannot succeed at any tests—

including Sanity tests.

REGAINING MAGIC POINTS: Magic Points are regenerated naturally as a by‐product of rest, fully

refreshing in 24 hours.

LOSING POW: An Investigator’s maximum number of Magic Points is set by his or how POW statistic;

if that statistic ever decreases, this maximum will also decrease. However, any points the character

already has are not lost – future refreshes will only bring to total back up to the revised maximum.


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Exhaustion An Investigator who works too long or faces extreme danger and injury without resting becomes

exhausted. When this comes into play is up to the Keeper, but a good rule of thumb is that going a

night without sleep or refusing to rest after losing SAN or Hit Points leads to exhaustion.

An exhausted Investigator suffers a penalty halving all skills, stat tests, and Sanity tests, and loses

1D6 Magic Points. The exhausted Investigator loses another 1D6 Magic Points after going another

night without sleep, after working hard for a few hours, or after running or fighting for a few

minutes. A full night’s sleep cures exhaustion.

Sleeplessness The first time your Investigator tries to sleep after suffering temporary insanity or gaining a new

disorder (see TEMPORARY INSANITY on page 48 and DISORDERS on page 49), you must make a

Sanity test. If it fails, your Investigator wakes in terror, losing the possibility of regaining any Magic

Points for 24 hours.


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Combat A serious fight, where people are trying to kill each other, is chaotic, frightening, and fast. That’s

what these rules represent. Being skilled, having better weapons, or being in a superior position

helps, but the inescapable randomness of combat can claim even the most skilled combatant’s life.

Lovecraft’s fiction presaged humanity’s urge to reduce any confrontation with the unnatural to base

combat. “The Shadow Over Innsmouth” features a massive military assault on a U.S. town. The artist

in “Pickman’s Model” blazes away with a revolver when the ghouls come. In “The Call of Cthulhu,”

Inspector Legrasse leads a raid on a Cthulhu cult that turns into a pitched battle. Johansen on the

Alert rams his ship through Cthulhu himself.

The Combat Round Combat is measured in rounds. A round is a few seconds, or as long as it takes everyone to complete

a single action.

The Keeper counts down by DEX for all characters, from highest to lowest. Each character acts when

his or her number comes up. If DEX scores tie, the actions occur at the same time or the Keeper can

choose some tiebreaker.

During a round, a combatant can attempt one of the following actions (each described further

below):

1. Aiming, or

2. Attacking, or

3. Performing a Called Shot, or

4. Attempting to Disarm an opponent, or

5. Dodging an opponent’s attack, or

6. Escaping from combat, or

7. Fighting Back against an opponent, or

8. Moving, or

9. Pinning an opponent in a grapple, or

10. Waiting, or

11. Any other short action that can be completed in a few seconds.

Aim Sacrifice one round to aim and gain a bonus to your Ranged Weapon attack next round, doubling the

chance to hit. Aiming requires no roll. After the next round, or if your Investigator suffers any

damage before attempting it, the bonus is lost.

Attack An “attack” encompasses anything from throwing a punch to firing a Thompson submachine gun.

The “standard” attack (ranged or hand‐to‐hand) is a skill test to see if your Investigator hits a target,

damage is inflicted based on the weapon used. The relevant skill is usually Ranged Weapons for a

gun, crossbow or similar, Throw for a thrown weapon, Melee Weapons for a hand‐to‐hand weapon,

or one of the unarmed combat skills (Fist/Punch, Kick, or Head Butt) for a brawling attack.

The number of shots fired in a single firearm attack depends on the weapon used—a bolt‐action rifle

fires one shot while a semi‐automatic pistol might fire two or three shots—but it’s always a single

attack roll and a single damage roll.


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Attacking with unarmed combat or a melee weapon (but not with a ranged weapon) also means

your Investigator is parrying and blocking all subsequent hand‐to‐hand attacks in the same round.

See DEFENSE ROLLS on page 32 for details.

Called Shot A called shot is a ranged attack which targets a particular body part (the head, the hand, the leg). A

called shot allows your Investigator to lob a stick of dynamite past cover to explode on the far side,

or to shoot someone in the leg and avoid body armor. If the attack is automatic gunfire that can hit

multiple targets, the called shot affects only the first target.

A called shot is more difficult than a standard attack, so it has a penalty:

PARTLY COVERED (half normal skill chance): The target is partially covered (half the body).

MOSTLY COVERED (one‐fifth normal skill chance): The target is mostly covered (all but a limb or

head).

Disarm An attempt to knock an object from the target’s grasp using the Grapple skill. This is possible only if

your Investigator has both hands free and is in hand‐to‐hand range. If your roll succeeds, the target

drops the object.

Attempting to disarm also means your Investigator is parrying and blocking all subsequent hand‐to‐

hand attacks in the same round. See DEFENSE ROLLS on page 32 for details.

Dodge This is a Dodge skill test to get out of the way of an attack (or a disarm or pin). This Opposed Test

(see OPPOSED TESTS on page 26) pits your Investigator’s Dodge skill against the attack roll. If your

roll overcomes the attack roll, your Investigator avoids harm. If both sides fail their opposed tests,

nobody suffers any damage. See DEFENSE ROLLS on page 32 for details.

Escape A roll to escape a pin. Roll either STR × 5 or Grapple, whichever is better. This acts as a defense roll

against the character pinning your Investigator (see DEFENSE ROLLS on page 32 for details); it’s

opposed by the pinning character’s attack roll against your Investigator. If the pinning character is

not attacking, the escape is opposed by either Grapple or STR × 5 (whichever is better). If the escape

roll succeeds, your Investigator is no longer pinned—and the escape roll defends against other

attacks until your Investigator’s next action. If it fails, your Investigator remains pinned and cannot

defend against attacks.

Fight Back If someone attacks your Investigator with a melee weapon or unarmed combat (not a ranged attack

or an explosive), your Investigator can fight back with unarmed combat skill (Fist/Punch, Kick, or

Head Butt) or with a Melee Weapons skill, with the goal of simultaneously blocking and

counterattacking (parrying). See DEFENSE ROLLS on page 32 for details.

Move An action that moves your Investigator a significant distance: 10 meters/yards jogging, 20

meters/yards running, or 30 meters/yards sprinting (or, you can move about 3 meters/yards while

performing some other action).


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Usually moving requires no roll, but if Investigators are running or sprinting, players may need to

make a DEX × 5 test to keep their footing. Fail, and your Investigator falls prone and must spend a

round recovering.

If there’s cover at the end of your Investigator’s movement, getting behind it provides protection

(see PROTECTION IN COMBAT on page 40). This can give your Investigator armor against ranged

attacks and explosives—if the Investigator is behind cover when the attack happens.

Pin An attempt to immobilize a target, either on the ground or up against something, using Grapple. This

is possible only if your Investigator has both hands free and is in hand‐to‐hand range. If it succeeds,

the target is pinned.

All unarmed or melee weapon attacks against a pinned target are double chance to hit. An

Investigator pinning a target can attack the pinned target in later rounds.

A pinned target can attempt escape once per round (see the ESCAPE action, above) but nothing else.

Attempting to pin a target also means your Investigator is parrying and blocking. See DEFENSE ROLLS

on page 32 for details.

Wait Investigators can choose to wait to take any action after their DEX order comes up. At any time

before your next round, you can insert your Investigator’s action before the next action in DEX

order. Your Investigator can’t wait until another character acts and then jump in before it’s resolved,

but your Investigator can jump in before the other character’s round comes up.

Anything Else Drink a test‐tube full of a glowing liquid, throw open an unlocked door, read a passage from an

arcane tome, grab a rope, reload a gun, stand up from a prone position—anything that takes a

moment’s concentration. The Keeper decides whether it requires a stat or skill test.

<box>One Action Per Round An Investigator can take only one action per round. Some high‐speed weapons, or even handguns,

might realistically fire off multiple rounds in that time, and weapons may even target multiple

different targets. Despite all this, the attack is resolved with a single roll (attacks which affect

potentially many people, or which deliver explosive damage to an area, are handled through a

LETHALITY RATING, see page 37).

If the idea of resolving this frenzy of activity with a single roll seems counterintuitive (“a good boxer

can throw three jabs a second!”) don’t think of every roll as a single action but rather the

accumulated outcome of as a few seconds of fighting or moving.

</box>

Attack Rolls An attack is a skill roll which inflicts damage, disarms or pins the target, depending on the attacker’s

action.

When making a roll for a hand‐to‐hand (unarmed or Melee Weapon) attack it is often a good idea to

leave the dice on the table in front of you for the remainder of the round. This is because any

subsequent hand‐to‐hand attacks launched against you by another combatant will be parried by

your attack roll in an Opposed Test (see OPPOSED TESTS on page 26).


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Critical Hits and Fumbles An attack roll that’s a critical success (see page 25) is a critical hit. A critical hit inflicts double

damage.

EXAMPLE: Entering the Temple of the New Light, Professor Walter Mason draws his handgun to stop

the shambling figure he has been chasing. He fires at the man. Normally, Walter’s skill with the

handgun gives him a 55% chance of hitting at normal range; Vanessa aces it and rolls an 03 on the

1D100 roll: a critical success! Normally Walter’s handgun would inflict 1D10 damage, but a critical hit

doubles it. Vanessa rolls a 7 and doubles it for 14 HP damage. The shabby man collapses.

An attack roll that fumbles (see page 25) is bad news. So too is any attack roll with a Ranged Weapon

that is equal to or higher than the weapon’s stated Malfunction (or Malf) number.

Consequences of weapon malfunctions and fumbles are determined by the Keeper, but can include:

1. A gun misfires, requiring 1D4 rounds to clear it.

2. A weapon drops and it takes a round to pick it back up.

3. The attacker accidentally hits a friend, a bystander, or himself or herself.

4. The attacker stumbles and falls.

EXAMPLE: Shortly after the gunshot has dropped the shabby man, several figures in purple robes

rush at Walter from nearby shadows. The front one is carrying a knife which he uses to try to stab the

startled professor. The cultist has a 45% skill with the knife but rolls a fumble (a 00). Sam, the Keeper,

decides that means this lead cultist falls over the body of the fallen man and falls prone.

Attack Modifiers for Ranged Attacks When you make an attack roll, it means the situation is out of control. Combat is chaotic and

unpredictable even for the most highly trained fighters. The combatants’ skill ratings and the luck of

the dice usually tell everything you need to know.

Bonuses and penalties in combat apply only in extraordinary circumstances. Some of the most

common situations are described below, but the Keeper is justified in imposing bonuses or penalties

to reflect any significant situation he or she believes might affect the chance of success.

No matter the bonus or penalty, a roll of 01 always hits and a roll of 00 (100) always misses.

Modifiers due to Target Distance

Each ranged weapon has a stated “base range” which reflects the normal distance it may be fired

without incurring any reduction in chance to hit.

If the character is trying to hit someone who is very close (at “point blank” range) – less than

a yard or two – his or her chance is doubled;

If the character is trying to hit a target beyond the weapon’s base range but less than twice

that range, the chance of success is halved;

If the character is trying to hit a target beyond twice the base range but less than 5 times

base range, the change is one‐fifth of normal;

Attempts to fire at targets further than 5 times base range will automatically fail.

Modifiers due to Attacker Preparedness

As described in the description for the AIM action (page 30), if a character has previously sacrificed

an entire combat round to take aim, his or her attack has twice normal chance to hit.


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Modifiers due to Called Shots

As described in the description for the CALLED SHOT action (page 31), if a character is trying to hit a

particular small part of a target, or a target who is partially covered, the chance of success is

reduced:

If attempting to hit a partially‐covered target or trying to hit a region that covers about half

the target’s body, the chance to hit is half normal.

If attempting to hit a mostly‐covered target or trying to hit a region that is small (e.g., a

hand), the chance to hit is one‐fifth of normal.

Modifiers due to Target Size

Larger targets are easier to hit. When firing a ranged (or thrown) weapon at creatures whose bulk is

above SIZ 30, the chance to hit is increased. For every 10 SIZ above 30, the attack gets a +5

percentile chance to hit.

Defense Rolls Dodging and hand‐to‐hand combat (with unarmed or with melee weapons) are tests that protect

your Investigator by opposing an attack roll.

Dodging and Fighting Back Your Investigator can Dodge or fight back against an incoming attack even before your Investigator’s

DEX order in a round. If you do this, it becomes your Investigator’s single action for that round. An

Investigator who has already taken another action that round can’t Dodge or fight back until the

next round.

A roll to Dodge opposes all hand‐to‐hand attacks that round, and lets your Investigator duck behind

cover to evade all ranged attacks that round, if you win the contest. Dodging never inflicts damage.

Fighting back blocks all hand‐to‐hand attacks that round, if you win the contest. It does not protect

you against ranged attacks unless you’re close enough to push the ranged weapon away. Choose an

offensive action for fighting back: attack, called shot, disarm, or pin. If your roll beats the attack,

your Investigator takes no damage and your Investigator’s action affects the attacker.

In order to Dodge or fight back, your Investigator must know an attack is coming and be physically

able to block or evade it. If your Investigator is pinned, if the attack occurs before he or she realizes

it, or if your Investigator can’t see or hear the attacker, your Investigator can’t Dodge or fight back.

Dodging Ranged Attacks An ordinary Dodge roll can avoid an arrow or a thrown weapon. Nobody can react as fast as bullets

and shrapnel, but your Investigator can use Dodge to scramble for cover. If your Investigator is

within three meters/yards of cover and knows gunfire or an explosion is imminent, make a Dodge

roll for the Investigator to get behind the cover. If there’s no cover, Dodging does no good. This is

why people get nervous when guns come out.

Defending After Attacking When your round comes up, declare your Investigator’s action—attack, called shot, disarm, or pin—

and make the roll. Your Investigator can harm, disarm or pin only one target a round (the attack

might hurt others, but all attacks have a single target).


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A roll to attack, disarm, pin, or make a called shot also opposes each unarmed combat (Fist/Punch,

Kick, Head Butt, Grapple) and Melee Weapons attack against your Investigator until your

Investigator’s next action. If an attack fails to overcome your roll, it does no harm.

To oppose an attack, your Investigator must know the attack is coming. That requires seeing or

hearing the attacker. The Investigator must also be physically able to block the Attack, if it is melee.

A pinned Investigator can’t defend, nor can an Investigator who has already successfully pinned a

target.

An attack roll with a ranged weapon does not oppose attack rolls against your Investigator.

EXAMPLE: Professor Walter Mason finds himself in a perilous situation. He has wandered into the

Temple of the New Light following a strange man (who he shot), but now finds himself set upon by a

small group of cultists. One of the murderous cultists has fallen flat on his face but two others are still

intent on doing harm to the professor. Walter has a DEX of 12 and his pistol is already drawn. The

closest of the cultists has a DEX of 12.

The cultist acts first, rushing Walter, trying to subdue him with a pin action. The cultist has a Grapple

skill of 40% and rolls 09, a standard success. Walter knows he can’t afford to be pinned, so he fights

back with Fist/Punch (which Walter only has at base chance of 50%). This is an opposed test, and

Vanessa rolls a 31 for Walter. That is also a standard success but is higher than the cultist’s roll so

overall it’s a win for Walter, who fends off the cultist. That’s it for Walter’s round since he has

already used his one action.

In the next round, the cultist attempts to pin Walter again. He rolls 45, failing. The professor shoots

with the attack action. Walter has 55% in Ranged Weapon (Handgun) and rolls 25. The shot hits.

Walter rolls high damage and the cultist collapses.

That same round, two more cultists reach Walter, daggers drawn. They act at DEX 11 and DEX 9.

They rush at Walter and attack. The first rolls 43, which fails. The next rolls 27, which succeeds.

Walter already acted this round, so he can’t try to Dodge or fight back. And his attack action used

Ranged Weapons, not Melee Weapons or an unarmed combat skill, so it cannot oppose the attack

roll. Walter takes damage from the knife.

Damage Combat is about inflicting damage. Each weapon or attack has a damage rating measured in dice.

When an attack hits, roll the weapon’s damage dice and subtract the result from the target’s Hit

Points.

If the attack is a melee attack, the amount of damage rolled may be modified by the attacker’s

Damage Bonus (see page 9). If the attack is a thrown missile weapon – like an axe or a spear – the

damage roll is modified by half the attacker’s damage bonus.

Certain weapons are specifically designed to STUN rather than damage. Such attacks do not reduce

the target’s Hit Points but may temporarily incapacitate. When a stunned individual next wishes to

take an action on their round they must attempt a CON × 5 test. If successful, the action continues as

normal. If it fails, the individual remains stunned and must attempt the same test next round to

recover. A character is considered stunned until either succeeding on the CON × 5 test or when the

combat ends, whichever happens first.

EXCESSIVE DAMAGE: If a character takes more than half of their current HP in a single attack, he or

she is considered stunned (as per above).


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UNCONSCIOUSNESS: If a character is reduced to 2 or fewer HP, he or she falls unconscious. An

unconscious individual is helpless and can be killed with a single attack without having to roll. At 3

HP or more (or after an hour passes), the individual regains consciousness.

PERMANENT INJURY: Any time your Investigator is reduced to 2 or fewer HP, make a CON × 5 test.

Failure indicates permanent injury. The Keeper selects a stat to be permanently reduced by the

number on the lowest ten‐sided die of the failed CON × 5 roll, to a minimum stat score of 3. If STR or

CON drop, adjust HP accordingly.

DEATH: If an attack brings a character to 0 HP, he or she is dead. HP do not go below 0.

<box>Ammo and Damage Many types of ranged weapons use some form of ammunition – whether arrows for a bow, bullets

for a gun, or batteries for a Taser. Each type of weapon carries a certain number of these and can

fire them at a certain number per game round. The weapons table on page 39 shows these

characteristics for a variety of ranged weapons.

Because Open Cthulhu resolves each attack using a single attack roll, the damage inflicted by such an

attack is based on the inherent assumption that the attacker is firing at the maximum possible rate

and will expend the stated amount of ammunition as part of the attack. If for some reason this is not

possible (e.g., the weapon doesn’t contain that many pieces of ammo, or the attacker has stated he

or she will be firing fewer than the maximum number), the damage inflicted should be reduced

proportionally (round upwards).

Weapons which can fire in different burst modes must have the requisite amount of ammo

remaining to use that mode (e.g., a sub‐machine gun can perform a long spray attack, but only if 20

bullets remain in the weapon; otherwise a different mode will need to be used).

EXAMPLE: Professor Walter Mason fires his light handgun at an assailant. The weapon has a rate‐of‐

fire of 3 bullets per round and does 1D10 damage. Unfortunately, Walter only has 2 bullets left in his

weapon. Thus, even though he rolls 7 points of damage on the die, his attack will only inflict 7 × 2/3 =

4.66, rounded up to 5. Next round, Walter is going to have to stop and spend a round reloading

before he can continue to fire his gun.

</box>

Healing There are four types of healing: Resuscitation, Stabilization, Treatment, and Recuperation.

RESUSCITATION: Sometimes it’s possible to resuscitate a dead character. If the Keeper says

resuscitation is possible, someone must make a First Aid test. This must occur within a number of

minutes after death equal to the victim’s CON score. If it succeeds, it restores 1D4 HP (doubled for a

critical success) and allows the patient to recover. If First Aid fails, the victim dies and may not be

resuscitated.

STABILIZATION: Stabilizing a wounded character with a successful First Aid test immediately heals

1D4 HP. A critical success doubles the amount healed; a fumble inflicts 1D4 damage. Once your

Investigator receives first aid, success or failure, the Investigator can’t benefit from it again until he

or she suffers damage again.

TREATMENT: Treatment is medical care in a hospital or equivalent, with extensive tools and

medicines. A doctor can attempt a Medicine test once per week: if treatment succeeds, the patient


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recovers 1D4 HP. This is doubled with a critical success, while a fumble inflicts 1D4 HP damage. At

the Keeper’s discretion, having less extensive tools and medicines may incur a penalty.

RECUPERATION: Over time, the human body repairs itself. A patient who rests in a safe place with

proper food and water can attempt a CON × 5 test once per day to recover 1 HP (in addition to any

HP recovered due to medical treatment). On a critical success, the patient regains 1D4; on a fumble,

the patient loses 1 HP.

Lethality Rating Certain attacks inflict damage well beyond the possibility of survival; a burst of machine gun fire or

an explosion makes fast work of human anatomy. Rather than rolling many dice for damage or many

separate attacks, a weapon like this has a Lethality rating.

If your Investigator hits with a weapon that has a Lethality rating, there’s a chance it simply kills the

target outright. Instead of rolling normal damage, roll percentile dice against the weapon’s Lethality

rating. If the Lethality test succeeds, a human target immediately drops to 0 HP. If the Lethality test

fails, add the two dice together as if they were individual D10s (0 is 10) and apply that as HP damage.

Lethality rolls do not fumble or critically succeed, but the attack roll can. If the attack roll is a critical

success, double the Lethality rating, and double the HP damage if the Lethality roll fails.

EXAMPLE: Professor Walter Mason has finished off the third cultist from the shootout and gone

deeper into the lair of the Seers of the New Light. He comes upon a room with six cultists inside,

meditating and unaware. He knows how fanatical they can be, so he doesn’t want to try subduing

them with just his pistol and threats. Instead, he pulls a stick of dynamite from his Gladstone bag,

lights it and throws it into the room. Sam, the Keeper says Vanessa doesn’t even need to make an

attack roll since the cultists are unaware of his presence and Walter can take his time. The Keeper

asks Vanessa to roll damage to the cultist struck by the dynamite. The dynamite stick has a Lethality

rating of 15%. Vanessa rolls percentile dice and scores an 80. That’s higher than the Lethality chance,

so the dynamite fails to kill the cultist outright. Instead Vanessa adds the dice together for hit point

damage: 8 + 10 = 18 HP. The cultist had 10 HP, so he dies in the blast anyway.

<box>Why Lethality Ratings? The Lethality rating replaces the need to roll lots of separate attacks and lots of dice for damage.

Without it, a common weapon like a Tommy Gun might require nine separate attacks and damage

rolls to spray nine targets, or a huge explosion might require rolling and adding up 12D6 for damage.

In the middle of combat, rolling that much breaks the tension.

If you’d rather roll damage the old way, it’s 1D6 damage for every 3% of Lethality. So, a weapon with

Lethality 15% would do 5D6 HP damage.

</box>

Kill Radius If a weapon has a Kill Radius, a successful attack inflicts a Lethality roll on each character in that

radius. The center of the Kill Radius is the initial target of the attack.

With explosive weapons, Kill Radius attacks don’t need to be as precise as ordinary attacks; hitting a

zone within the Kill Radius of a target is enough. That doubles the normal chance to hit.


Page 38

A failed attack roll means the Kill Radius lands harmlessly outside the intended area. The attack does

no harm—but may still cause shock (see SHOCK, below). Whether a failed Kill Radius attack does

unwanted collateral damage is up to the Keeper.

MANY TARGETS: A single attack with a Kill Radius usually affects everyone in the Kill Radius. If that

doesn’t make sense for the situation, the Keeper can decide who gets hit.

The Keeper is welcome to let players roll the Lethality results for NPCs to speed things up. But really,

you need to roll Lethality only for characters who are important enough to track in detail. Since even

a failed Lethality roll inflicts between 2 and 20 damage, it’s safe to just assume that most humans

caught in a Kill Radius are either dead or incapacitated.

<box>Lethality and Huge or Unnatural Targets The Lethality Ratings are designed to reflect the damage to human beings, or other entities which

are similarly vulnerable. If the Investigators are fighting much larger, or more alien adversaries even

a spray from a Tommy gun might be shrugged off.

If the target of an attack with a Lethality Rating is considered huge, then don’t roll for Lethality as

normal. The target simply takes a number of Hit Points damage equal to the Lethality Rating. For

creatures that have special resilience to physical damage the Keeper may instead rule that the

number of Hit Points taken as damage is equal to the sum of the individual dice rolled for Lethal

Damage (treating the 1D100 roll as two separate D10s and then adding them together).

If the target is entirely extraterrestrial or extradimensional, it is the Keeper’s call as to how Lethal

damage affects it. The listings for Cthulhu Mythos and mundane creatures in this book provide

guidelines for handling Lethal Damage against each type of monstrosity.

</box>

Shock An attack with a Kill Radius is terrifying. Any time your Investigator knows that he or she is inside an

intended Kill Radius, even if the attack roll misses, your Investigator’s fear‐riddled nervous system

forces him or her to go to ground. Your Investigator must either find cover or go prone as his or her

next action. Your Investigator can stifle his or her terror and act normally at a cost of 1 SAN.

In a firefight, often targets don’t realize they’re under attack. When in doubt, call for a Spot Hidden

or Listen roll (whichever seems most appropriate). An unaware target isn’t subject to shock effects.

A character adapted to violence (see ADAPTING TO SAN LOSS on page 53) loses no SAN for braving a

situation which induces shock. For NPCs, it’s easiest to assume the average human goes to ground

when shocked. Only insane, hardened, or fanatical enemies stand up in the face of fire.

EXAMPLE: Even the meditating Seers of the New Light have been stirred by Professor Mason’s

gunshots and dynamite. One of their guards leans around a corner with a Thompson Submachine

Gun and fires a burst. The guard’s Ranged Weapons (Sub‐Machine Gun) skill is 30% and he rolls 35,

missing. But it shocks the professor. On his round, Vanessa has to choose: will Walter try to attack

anyway and lose 1 SAN from the terror or run for cover. He runs for cover.


Page 39

<box>Sample Hand‐to‐Hand Weapons

Weapon Relevant Skill Damage Fist/Punch Fist/Punch 1D3 + damage bonus

Head Butt Head Butt 1D4 + damage bonus

Kick Kick 1D6 + damage bonus

Knife, Small (switchblade etc.) Melee Weapon (Knife) 1D4 + damage bonus

Knife, Large Melee Weapon (Knife) 1D4+2 + damage bonus

Axe Melee Weapon (Axe) 1D8+2 + damage bonus

Hatchet or Sickle Melee Weapon (Axe) 1D6+1 + damage bonus

Sword Melee Weapon (Sword) 1D8+1 + damage bonus

Club, Small (nightstick etc.) Melee Weapon (Club) 1D6 + damage bonus

Blackjack or Cricket Bat Melee Weapon (Club) 1D8 + damage bonus

Taser (contact type) Fist/Punch stun

</box>

<box>Sample Ranged Weapons (Light—Medium)

Weapon Skill Damage Base Range

Ammo per rnd *

Reload time

Malf. Eras

Thrown Rock

Throw 1D4 + half damage bonus

3 yd × STR

1 of 1 N/A N/A any

Thrown Axe

Throw 1D6 + half damage bonus

4 yd × STR

1 of 1 N/A N/A any

Thrown Spear

Throw 1D8+1 + half damage bonus

1 yd × STR

1 of 1 N/A N/A any

Sling & Stones

Ranged Weapon (Sling)

1D8 + half damage bonus

55 yds 1 of 1 N/A N/A any

Shortbow & Arrow

Ranged Weapon (Bow/Crossbow)

1D4+1 30 yds 1 of 1 3rnd 99 any

Longbow & Arrow

Ranged Weapon (Bow/Crossbow)

1D8 60 yds 1 of 1 3rnd 99 antiquity+

Crossbow Ranged Weapon (Bow/Crossbow)

1D8 40 yds 1 of 1 3 rnd 99 antiquity+

Wheellock Pistol

Ranged Weapon (Wheelllock)

1D6 8 yds 1 of 1 3rnd 93 1500+

Blunderbuss Ranged Weapon (Flintlock)

1D10/1D6/1D4

3/13/ 26 yds

1 of 1 3 rnd 90 1500+

Flintlock Pistol

Ranged Weapon (Flintlock)

1D6+1 10 yds 1 of 1 3 rnd 95 1610+

Musket Ranged Weapon (Musket)

1D10+4 70 yds 1 of 1 3 rnd 95 1610+

Handgun, small caliber

Ranged Weapon (Handgun)

1D8 15 yds 3 of 6 1 rnd 00 1840s+

Handgun, mid caliber


1D10 15 yds 2 of 6 1 rnd 00 1840s+

Handgun, high caliber


1D10+2 15 yds 1 of 6 1 rnd 00 1840s+

Rifle Ranged Weapon (Rifle)

1D12+2 110 yds

1 of 5 (fires every 2nd rnd)

1 rnd 00 1860s+

Shotgun Ranged Weapon (Shotgun)

4D6/2D6/1D6 10/20/ 50 yds

1 of 2 1 rnd 00 1830s+


Page 40

Weapon Skill Damage Base Range

Ammo per rnd *

Reload time

Malf. Eras

Taser (pistol type)


stun 4yds 1 of 1 varies 00 1990s+

Submachine gun in single shot mode

Ranged Weapon (Sub‐machine gun)

1D10 50yds 1 of 30 1rnd 97 WWI +

* Note: In this table and the one immediately following, the Ammo per rnd column shows two

numbers (“X of Y”). The first number (“X”) is the projectiles fired by the weapon in a normal round;

the second (“Y”) is the amount of ammunition held in the weapon when fully loaded.

Sample Ranged Weapons (Lethality Ratings)

Weapon Skill Lethality Kill Radius

Base Range

Ammo per rnd *

Reload time

Malf. Eras

Submachine gun in short burst


10% N/A 50yds 3 of 30 1rnd 97 WWI +

Submachine gun in long burst


10% 1 yd 50yds 5 of 30 1rnd 97 WWI +

Submachine gun in short spray


10% 2 yd 50yds 10 of 30 1rnd 97 WWI +

Submachine gun in long spray


10% 3 yd 50yds 20 of 30 1rnd 97 WWI +

Thrown Grenade

Throw 15% 10 yds 4 yd × STR

1 of 1 N/A 95 WWI +

Dynamite Stick

Varies 15% 10 yds N/A 1 of 1 N/A 95 1860s+

Large explosion

Varies 60% 75 yds N/A 1 of 1 N/A N/A 20th C+

</box>

Protection in Combat We’ve seen how to injure, kill, and dismember targets, but how do you protect them? The best way

is with some form of armor or cover. Both reduce the amount of damage suffered from a successful

attack.

Armor and Cover work the same way for normal damage, but slightly differently for attacks with a

Lethality Rating. If an individual has more than one source of protection (such as wearing armor

while also behind a wall), add them together.

BODY ARMOR: Body armor reduces the damage of an ordinary attack by its Armor Rating. Body

armor protects against the damage of a failed Lethality roll, but does nothing whatsoever against a

successful Lethality roll.

COVER: Finding cover means using a hard barrier as armor against attack. Cover protects more

completely than body armor. If you have cover against a Lethality attack, the Lethality roll

automatically fails, but still inflicts the sum of the dice as damage. Subtract the cover’s Armor rating

from that damage.


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Armor Armor Rating

Heavy Leather Jacket 1

Light Antique Armor 2

Medium Antique Armor, Standard Kevlar 3

Reinforced Kevlar 4

Platemail Armor, Wooden wall or door, Vehicle 5

Concrete wall or rock 10

Reinforced wall or blast barrier 15

Tank armor 20

EXAMPLE: Professor Walter Mason, wounded and shocked, reloads his pistol and takes aim at the

guard leaning around the corner. The guard has a wall for cover that blocks 5 damage, so Walter

tries a Called Shot. The Keeper says the cover reduces the chance to hit by half, reducing the

professor’s 55% Firearms to 28%. The dice come up 09—a hit! Vanessa rolls 1D10 damage for the

attack and gets a 9. The guard drops.

Other Threats to Life and Limb The world is full of threats – combat isn’t the only thing that can kill an Investigator.

Poison and Disease Every poison or disease has two ratings: Speed and Damage.

Speed indicates how soon the poison or disease inflicts damage. A poison inflicts damage once and

then passes from your Investigator’s system. A disease requires a series of CON tests to resist

damage.

Damage is ordinary HP for a disease, while poisons have Lethality ratings.

POISONS: A poison has a Lethality rating. See LETHALITY RATING on page 37 for the mechanics of

making a Lethality roll. If the Lethality roll fails, the victim then makes a CON × 5 test to withstand

harm. Success means half damage, and a critical success means the victim loses only 1 HP. A fumble

doubles the damage. Hospitalization doubles the chances for a victim’s CON test.

EXAMPLE: Venturing further into the Temple of the New Light, Professor Walter Mason is surprised

when something erupts from the floor – a hideous monstrosity. He flees in terror. Escaping from the

creature, he is alarmed to discover that his flesh shows a bright red mark from where the

monstrosity’s stinger struck him. The creature’s sting contained an ugly neurotoxin. The Keeper says

the toxin is a poison with Speed of 1D6 hours and 10% Lethality. The symptoms are convulsions,

spasms, and circulatory failure. The Keeper rolls for the poison’s Lethality rating and fails with a 19,

inflicting (1+9) 10 HP. Walter has a CON of 14, so his CON × 5 test is 70%. He’s hospitalized when it

takes effect, which doubles the chance, bringing his chance to the maximum 99%. He succeeds with a

23. The damage is halved to 5.

DISEASES: Diseases inflict HP damage. If your Investigator succeeds at a CON × 5 test, he or she

suffers half damage and recovers from the disease. On a failure, he or she suffers full damage and

must make the CON × 5 test again after another Speed interval. A fumbled CON test doubles the

damage. While under the effects of a disease, the Investigator cannot recover Hit Points.

Hospitalization doubles the CON test. Serious diseases may come with a penalty to the CON test.


Page 42

A persistent or incurable disease means succeeding at the CON test only buys time; the disease

subsides, and your Investigator recovers lost HP. But every time the Investigator is badly hurt (losing

more than half his or her HP) or suffers from some other poison or disease, the Investigator must

make a CON × 5 test to resist a resurgence or relapse.

ANTIDOTES: Many poisons and diseases can be cured with medication. If a physician has the

antidote for a poison or the right antibiotics for a disease, a Medicine or Pharmacy test before the

ailment takes effect renders the poison or disease harmless. An antidote given after the ailment

takes effect halves the Lethality rating and/or the HP damage.

EXAMPLE: Sadly for Professor Mason, facing the monstrosity in the Temple of the New Light also

exposed him to alien microbes that have catastrophic effects on the human body. The Keeper says it’s

a disease with a Speed of 1D6 days, a CON roll at Very Hard (CON × 1) difficulty, Damage of 1D6, and

symptoms of fever, weakness, diarrhea, and shock. For Speed, the Keeper rolls 3 on 1D6, so the

disease sets in after three days. Walter’s CON is 12 so normally his roll to resist the damage would be

a 1D100 trying to roll 12 or less – not very good odds. Thankfully, the good professor is hospitalized

so the chance of resistance is doubled, giving him a target of 24 for the test. He fails with a roll of 54.

The 1D6 damage roll comes up 4, so Walter loses 4 HP. That brings him down to 2 HP, and he slips

into a coma.

The Keeper rolls 1D6 for the next interval and gets a 4, so in four days Walter must attempt another

CON test. The player rolls 18, succeeding. The 1D6 damage roll is 2, halved for the successful CON

roll, so Walter loses 1 HP. He has beaten the disease and can begin to recover.

Poison Entry Route Speed Lethality Symptoms Antidote? Spider venom Bite 1D6 hours 5% Pain, chills,

nausea; possibly necrosis

Yes

dangerous drug administered with failed Pharmacy skill use

Varies 1D6 hours 5% Usually pain, diarrhea, convulsions, or asphyxiation

Yes

Arsenic Ingestion 1D6 hours 10% Pain, diarrhea, cramping

No

Scorpion or rattlesnake venom

Bite or sting 1D6 hours 10% Pain, weakness, hemorrhaging, convulsions

Yes

Phosgene gas Inhalation 2D6 hours 15% Blistering, coughing blood, asphyxiation

No

Hydrogen cyanide gas

Inhalation 1D6 rounds 20% Asphyxiation Yes

Sarin gas Inhalation or absorption through skin

2D6 rounds 20% Muscle contractions, spasms, asphyxiation

Yes

Ricin Injection or powder inhalation

2D6 hours 20% Diarrhea, shock, seizures, circulatory failure

No


Page 43

Disease Route Speed Con Test Difficulty

Damage Symptoms Cure

Bacterial meningitis

Airborne 1D6 days Very Hard

(CON × 1) 1D4 Stiff neck,

nausea, confusion

Antibiotics

Bacterial pneumonia

Inhalation 1D6 days Normal

(CON × 5) 1D6 Cough, fever,

chills Antibiotics

Gangrene Dirty wounds 1D6 days Hard (CON

× 2) 1D4 Discoloration,

oozing, numbness

Antibiotics, excision, or amputation

Plague (Bubonic or Pneumonic)

Flea bite (bubonic plague), inhalation (pneumonic plague)

1D6 days Normal

(CON × 5) 1D6 Fever, chills,

lymph node swelling, coughing (if pneumonic), shock

Antibiotics

Ebola virus Contact with infected blood, bodies, or meat

1D6 days Very Hard

(CON × 1) 1D6 Fever,

diarrhea, nausea, bleeding, shock

None

Falling Falling is extremely dangerous to humans. Even a bad slip can be fatal. A fall from a short distance

(one to three meters/yards) does 1D6 damage, or 2D6 if it’s a particularly uncontrolled fall. Beyond

that, a fall instead has a Lethality rating of 1% per meter/yard fallen. An Investigator who survives a

fall must make a CON × 5 test or be stunned.

Impacts Slamming into a barrier can be deadly. It has a Lethality rating of 10% for every 40 kph (25 mph) of

speed. Double the Lethality rating if your Investigator slams into a wall and there’s nowhere to

tumble. An Investigator who survives an impact must make a CON × 5 test or be stunned.

Suffocation or Drowning Suffocation is a slow death. If your Investigator takes a deep breath before holding it, he or she can

go without breathing for CON × 5 rounds. After that, your Investigator’s oxygen‐starved brain begins

to die. Once every round, make a CON × 5 test. If it fails, your Investigator suffers 1D6 HP damage. If

the CON test succeeds, your Investigator suffers 1 HP damage instead. This continues until your

Investigator can breathe again or he or she dies.

If your Investigator doesn’t get a breath before suffocating, the damage starts immediately and lasts

until someone clears his or her airway with a First Aid test. Armor does not protect against

suffocation damage.


Page 44

Damage from Fire Fire damage suffered depends on the flame’s intensity. The victim suffers a damage roll every round

of exposure.

Intensity Example Damage

Minor Candle 1 HP/round

Moderate Flaming brand; momentary exposure to a larger fire

1D6 HPs/round

Large Campfire 2D6 HPs/round

Major Scalding steam; bonfire; blast furnace

Lethality (10%) each round

After taking damage from any moderate, large or major source of fire, the victim must make a

DEX × 5 test or catch fire, suffering half damage each round until extinguished. Being surrounded by

a raging fire also causes suffocation as the fire consumes oxygen. (See SUFFOCATION above.)

Extreme Cold Investigators can last for CON in minutes exposed to freezing temperatures unprepared, or CON × 5

minutes if partially prepared. Fully prepared and well equipped (decked out for an Arctic expedition,

for example) Investigators can last CON hours.

After this, their bodies start to fail. Players must make a CON × 5 test every five minutes. Each failure

reduces CON by 1. When an Investigator’s CON hits 1, the Investigator can no longer move and

suffers 1D8 HP cold damage every five minutes. Exposure to warmth and shelter restores 1 point of

CON per minute. Hit Points heal normally.

The Aftermath When the smoke clears and the fighting stops, it’s time for the Keeper to look to the consequences

of combat. There are always consequences.

First, violence damages sanity. Unless your Investigator is a hardened operator, getting into a deadly

fight calls for a Sanity roll. So does getting hurt. So does killing someone. (See THREATS TO SAN on

page 45).

Next, was anyone killed or badly hurt? If so, who’s going to come looking for them? How soon until

detectives start combing the scene for spilled blood, shell casings, shoe marks, or tire tracks?


Page 45

Sanity Sanity Points represent the resilience of the relationship between your Investigator’s personality and

the world. With high SAN, your Investigator has confidence in his or her place in the world. A high

SAN score is marked by insight, self‐awareness, and a life‐affirming view of reality. With low SAN, the

deadly truth of the universe has begun to overwhelm your Investigator. With no SAN, your

Investigator is forever lost.

Sanity losses look like: 0/1D4 or 1D6/1D20. The number on the left is how much SAN your

Investigator loses on a success; the one on the right is how much SAN your Investigator loses on a

failure.

When your Investigator faces a threat to sanity, roll his or her current SAN or lower to take a

diminished loss of SAN points; roll higher than your Investigator’s SAN and he or she suffers a

greater loss of SAN points.

Rules of Thumb for SAN Loss A critical success with a Sanity roll means your Investigator loses the least possible SAN. For

example, if the loss for succeeding at the Sanity roll would have been 1D4, he or she loses 1 point.

Fumbling a Sanity roll means your Investigator loses the most possible SAN. For example, if the loss

for failing the Sanity roll would have been 1D20, he or she loses 20 points.

Threats to SAN The three major classes of threat to SAN are Violence, Helplessness and the Cthulhu Mythos.

These categories can overlap. Being tied up and tortured might trigger both Violence and

Helplessness. It’s up to the Keeper to decide which aspects affects the Investigator.

Violence Killing other humans is inherently harmful to sanity. While wrestling and punching people is within

biological norms, bludgeoning someone to death is not instinctive. The blasting noise and fire of

violence overwhelm the human brain. Violence can drive you insane if you’re not careful.

In combat, you must make a Sanity test for a trauma the first time it happens in that fight. Outside of

combat, every individual incident triggers its own SAN loss.

Helplessness The essential human impulse is to act. True inactivity is unwholesome to the human psyche.

Note that helplessness often makes violence worse, just like violence makes helplessness worse.

The Cthulhu Mythos Finally, there’s the unnatural creatures and gods of the Cthulhu Mythos, the inhuman things that

haunt the edges of existence. These beings (and even knowledge of their existence) troubles us

because it is wholly outside of human experience. It wounds our sense of connection to the world by

causing huge gaps in understanding.

This is why your Cthulhu Mythos skill limits maximum SAN. The more you understand of man’s

actual position in the cosmos, the harder it is to navigate the “real” world.

If an Investigator faces the Cthulhu Mythos and loses 0 SAN, it may mean the Investigator has

adapted to the reality of the Mythos in some small way—or it may mean simple denial, refusing to

admit the unnatural experience was real. It’s up to the player.


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Suffering Violence Loss

Ambushed or hit by gunfire 0/1

Find a corpse or a mangled carcass 0/1

Find mutilated corpse of infant or loved one 0/1D4

Stabbed, strangled or shot 0/1D4

Suffer a permanent injury 0/1D6

Set on fire 0/1D6

Reduced to 2 HP or less 0/1D6

Tortured 0/1D10

Inflicting Violence Loss

Incapacitate or cripple an innocent 0/1D4

Destroy a teammate’s body to thwart investigation* 0/1D4

Kill in defense of oneself or another* 0/1D4

Kill a murderous enemy in cold blood* 0/1D6

Torture a victim 0/1D8

Accidentally kill an innocent* 0/1D8

Kill an innocent in cold blood, … even for a very good reason* 1/1D10

* For a failed roll, add 1 per victim beyond the first, up to the maximum possible die‐roll: 4 for 1D4, 6 for 1D6, etc.

Helplessness Loss

Being fired from one’s job 0/1

Nearly getting friends/family hurt or killed 0/1

Being informed of unexpected bankruptcy 0/1

A friend suffers permanent harm or gains a disorder 0/1

Being disowned by friends/family 0/1D4

Sentenced to a prison term 0/1D4

Waking paralyzed or blind 0/1D4

Find a friend’s remains 0/1D4

Friends/family suffer permanent harm or gains a disorder 1/1D4

Flung into a pit of corpses 0/1D4

See or hear a friend being gruesomely killed 0/1D6

Learn friend/family‐member has been killed 1/1D6

See or hear a friend/family‐member gruesomely killed 1/1D8


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The Cthulhu Mythos Loss

Attempting Psychotherapy on a character who lost SAN to the Cthulhu Mythos 0/1

Witnessing a supernatural effect that’s apparently benign 0/1

Witnessing a violent supernatural effect 0/1D6

Seeing a corpse walk 0/1D6

Subjected to an overtly supernatural effect 0/1D6

Suffering a violent supernatural assault 1/1D8 or more

Insanity and Disorders Investigators who lose excessive SAN lose control of themselves, suffering insanity and mental

disorders.

TEMPORARY INSANITY (PAGE 48): An Investigator who loses 5 or more points of SAN in a single roll

suffers temporary insanity.

DISORDER (PAGE 49): Every time your Investigator’s SAN is reduced to his or her Breaking Point (see

DETAILED DESCRIPTION: DERIVED ATTRIBUTES on page 9), he or she gains a new disorder.

Immediately reset your Investigator’s Breaking Point to your Investigator’s current SAN minus POW.

Even if SAN rises back above the old Breaking Point, the disorder and the new Breaking Point remain.

PERMANENT INSANITY (PAGE 52): If your Investigator hits 0 SAN, he or she suffers permanent

insanity and becomes the property of the Keeper.

EXAMPLE: Vanessa’s Professor of Medieval Alchemy, Walter Mason, has a POW of 11. His starting

SAN was 55, so his Breaking Point is 55 – 11 = 44. During his recent encounter with the Temple of the

New Light, he found his fellow Investigator Harvey Carter’s corpse, then killed four cultists in two

shootouts and six in cold blood with a stick of dynamite.

Finding his friend’s remains cost 0/1D4 SAN. He succeeded at the Sanity roll, so he lost no points.

After the shootout with three knife‐wielding cultists, the Keeper said he’d lose 0/1D4 SAN. Walter

failed the Sanity roll and lost 4 points, bringing his current SAN down to 51.

After blowing up a roomful of cultists with a stick of dynamite, Walter’s SAN roll failed. The loss was

1D6 plus 1 per victim beyond the first, up to a maximum of 6. There were six victims so the failed roll

cost Walter 6 SAN. He went temporarily insane from the stress and trauma.

Then in the shootout with the guard, Walter lost 1 SAN for the shock of coming under fire from the

Tommy Gun. That brought his SAN down to 44, his Breaking Point. Vanessa made a note that Walter

would soon develop a disorder. She then reset Walters’s Breaking Point to 37: the Investigator’s new

SAN (48) minus his POW (11).

In the same shooting, Professor Mason faced a 0/1 loss for being shot and a 0/1D4 loss for killing the

guard in self‐defense. Walter failed the first Sanity roll and lost 1 SAN. Then he failed the other and

rolled 4 on the 1D4. That brought him to 43.


Page 48

When Walter was ambushed by a half‐glimpsed monstrosity a little while later, he faced a 1D4/1D10

SAN loss from the Cthulhu Mythos. His Sanity roll failed, but with a lucky roll of 2, he lost only 2 SAN,

bringing him to 41.

Finally, he went to 1 HP thanks to the disease he caught from the monstrosity. When Walter Mason

awakens and realizes how close he came to death, he faces a 0/1D6 loss. He fails the roll, rolls 6 on

1D6, and loses 6 SAN. That means temporary insanity—and it brings him past the Breaking Point

again. The player resets Walter’s Breaking Point to 24 (current SAN 35, minus 11) and makes a note

that he’ll develop yet another disorder.

Temporary Insanity In a moment of overwhelming stress—after losing 5 or more SAN in a single roll—your Investigator

loses self‐control. We call it temporary insanity. For a short time, you cannot control your

Investigator’s actions. Your Investigator’s primitive brain switches to pure panic, with one of three

possible responses: Flee, Struggle, or Submit.

Work with the Keeper to determine which stance your Investigator takes. Each is more likely in some

circumstances than others.

If the circumstances are calm, someone making a Psychoanalysis (or similar) roll can talk your

Investigator down from temporary insanity. Otherwise your Investigator loses control until the

insanity runs its course.

Flee Your Investigator must move away from the SAN‐affecting stimulus at top speed in any direction.

Your Investigator must do this for a number of rounds equal to his or her CON, whereupon your

Investigator falls to the ground exhausted (see EXHAUSTION on page 29), or until your Investigator

feels “safe”, whichever happens first. This is a common reaction against Cthulhu Mythos and

Violence SAN threats.

Struggle This is lashing out randomly at the nearest threat, no matter how insurmountable it might be. Once

this course is set upon, your Investigator has no choice but to fight until he or she is killed,

unconscious, or restrained. This is a common reaction against Helplessness and Violence SAN

threats.

Submit This is shutting down or passing out from shock. If conscious, your Investigator is catatonic and

paralyzed until the Keeper decides he or she snaps out of it. When your Investigator comes to, it’s

likely he or she has suppressed the trauma that caused his or her collapse. Remembering details

requires an INT × 5 test and is terribly stressful. This is a common reaction against Cthulhu Mythos

and Helplessness SAN threats.

Understanding the Cthulhu Mythos Whenever an Investigator goes Temporarily Insane or develops a Disorder due to an encounter with

the Cthulhu Mythos, he or she also gains some deeper understanding of the true nature of reality.

On the first such occasion, the Investigator gains 5 percentiles in the Cthulhu Mythos skill; each

subsequent occasion grants a further 1 percentile. This increase also serves to reduce the

Investigator’s maximum SAN (and if current SAN is higher than this value, also causes it to drop to

the new maximum).


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<box>Optional Rule: Insane Insight Sometimes Investigators who face massive psychological damage from unnatural trauma come away

with strange insights. If your Investigator suffers temporary insanity due to a Mythos trauma, he or

she might gain some special insight into the specific creature or Mythos Power encountered.

Immediately after going insane, the Investigator can attempt an INT × 5 test – if this roll fails, the

Keeper can provide the Investigator with some salient detail about the monstrosity, which may

prove helpful in defeating it.

</box>

EXAMPLE: Prior to his deadly encounter at the Temple of the New Light, Professor Walter Mason had

never encountered the forces of the Cthulhu Mythos first‐hand. His Cthulhu Mythos skill was 0%.

When encountering the half‐seen monstrosity, he fortunately only lost a handful of SAN points – but

later when he learned of the disgusting and unworldly disease that he had contracted from the thing,

he lapsed into Temporary Insanity. At this point he immediately gained 5 percentile points in Cthulhu

Mythos. The Keeper also permitted him an Insane Insight roll against his INT × 5 (80). Vanessa rolled

a 91, normally an unlucky roll but in this case, it allowed Walter’s logical brain to take a back seat as

his subconscious began to piece together the horrific implications of what it has experienced. He

suddenly understood that the terrible thing is somehow linked with the ancient Persian amulet whose

theft first started him on this whole adventure. Later on, when Walter realized that he almost died

from the alien disease he picked up from the Mythos monster, he experienced a second bout of

Temporary Insanity. Because he already had some Cthulhu Mythos skill, this experience only gave

him an increase of one percentile, bringing his Cthulhu Mythos to 6%.

Disorders An Investigator whose SAN reaches the Breaking Point gains a disorder. When suffering from a

disorder, the mind maladapts to mental trauma with long‐term neuroses. A disorder is like a release

valve for intolerable stress. Indulging in it helps your Investigator cope. It’s possible to suffer from

multiple disorders at the same time.

Any disorder is negative in the long term, but some are worse than others. Whatever the source of

the disorder, it takes the form of an irrational adaptation to the trauma that produced it. It may

manifest a few hours after the trauma, or it might take days, weeks, or months to appear. The player

and the Keeper negotiate the exact nature of your Investigator’s psychological trauma, so it makes

sense. For example, if your Investigator saw a loved one die in a fire, developing pyrophobia makes

sense.

Acute Episodes A disorder is a chronic, ongoing condition. It lurks under the surface, threatening to erupt when

things get bad.

Any time your Investigator loses SAN, and any time your Investigator faces a trigger that pertains

directly to his or her disorder, you must make a follow‐up SAN roll. If that fails, your Investigator’s

disorder takes over. If your Investigator suffers from more than one, the Keeper decides which

comes to the fore. As long as the Investigator is in the crisis or in the presence of the trigger, he or

she succumbs to the disorder’s internal logic and must act accordingly.

Suffering an acute episode of a disorder often means your Investigator can’t take some actions (or

can attempt them only with a penalty), or your Investigator must take some actions. The Keeper

always decides the exact repercussions, and whether it happens immediately or builds gradually, in

the aftermath of the trauma.


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When your Investigator is going through an episode, it is obvious to everyone that something is

wrong. A Psychoanalysis roll can diagnose your Investigator’s particular disorder.

Someone who makes a Psychoanalysis roll can talk your Investigator down despite the crisis or the

presence of the trigger, reducing the impact of the disorder so the Investigator can regain self‐

control. That takes a few minutes.

Sample Disorders There are many adaptations the mind makes when exposed to traumatic events, whether they be

violence and gore, feelings of utter helplessness, or the inherent “wrongness” of Cthulhu Mythos

beings. The specific disorder received by an Investigator should never be a random roll on a table

but something specifically selected to relate to the trauma they suffered.

Addiction

Addictions are a reliance on a harmful habit or substance to get one through the stress of life. No

matter how much stress and harm the addiction causes, a part of your Investigator needs the relief it

offers—even knowing that it might ruin relationships and even kill him or her in the end.

Addiction can be low‐key and manageable. But when things go bad, your Investigator will do

irrational, unreasonable, self‐destructive things to feed it. If he or she goes a day without feeding the

addiction, your Investigator suffers a penalty which halves every test until he or she gives in to it.

Amnesia

This is the most common disorder to result from an encounter with the bizarre or unnatural. The

brain cannot process the event. Everything surrounding the episode is blank unless your Investigator

finds a way to bring it back.

Depression

Depression means total despair, a crushing inability to get anything done. It sometimes takes the

shape of overwhelming guilt. It’s caused by biological and psychological factors and is triggered by

reminders of the mental trauma your Investigator suffered or inflicted. During an acute episode, all

skills are halved.

Hysterical Blindness / Deafness / Paralysis

Collectively called conversion disorder, this can manifest either as non‐physical blindness, deafness,

or paralysis (pick one). Whenever you fail a Sanity test, the disorder strikes and leaves your

Investigator blind, deaf, or paralyzed with numbness and tremors until the source of stress goes

away.

Mania

Your Investigator displays a euphoric and perhaps irritable mood that is consistently present. This

may include frenzied activity for no obvious reason, uncharacteristic garrulousness, a random

stream‐of‐consciousness flow of ideas, or difficulty sleeping. During an acute episode all tasks which

require concentration or fine control are at one‐fifth chance.

Megalomania / Narcissistic

What does it mean to look upon the face of a dead god and live? Some see themselves as messiah

figures. Others realize this elevated perspective exempts them from ordinary morality. When this

disorder is triggered, it makes your Investigator impossible to interact with; all uses of CHA, Fast

Talk, Persuade, and Psychoanalysis fail, as every doubt about your Investigator’s superiority fills him

or her with indignation.


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Multiple Personalities

Called Dissociative Identity Disorder. Most of the time, your Investigator seems fine, but in an acute

episode—when under extreme stress—he or she takes on an alternate identity with its own

personality and memories. The longer your Investigator suffers this disorder, the more alternate

identities may surface. The Keeper decides when and whether you keep control of your

Investigator’s behavior.

Obsession

Your Investigator becomes fixated on some person, place, event, act, or idea. In an acute episode,

any long‐term action or skill use—anything taking more than a day or two—is halved because your

Investigator’s mind is so often wrapped around its obsession.

Paranoia

A state of extreme suspicion, in which a fear of invisible enemies pervades one’s world‐view.

Paranoiacs interpret any event as a clue to a conspiracy against them. Unless your Investigator finds

a way to stifle his or her paranoia, he or she can’t trust or rely on anyone.

Paraphilias

This is a general classification for psychosexual disorders which revolve around a desire for sexual

gratification through something other than interaction with another human being. While an

interesting character quirk, such disorders can be uncomfortable to bring to the game table (and

thus should only be given to Investigators if everyone in the game is alright with such subject

matter).

Phobia or Philia

A common affliction arising from traumatic experiences is the development of an irrational fear of

something related (directly or by association) with the incident. These are called phobias and can be

quite debilitating. Whenever an Investigator is in the presence of a trigger for his or her phobia, they

have little choice but to suffer the Flee or Submit response to temporary insanity (see page 48). A

table nearby provides some examples of phobias; searching online will reveal a huge array of other

(sometimes quite weird) phobias.

A less common response to experiencing something shocking is the development of an irrational

fetish or allure for something odd that is associated with the situation (perhaps which somehow

related to the Investigator’s survival). These are called philias and work in a similar way to phobias in

that whenever the afflicted Investigator is in the presence of his or her irrational fetish a SAN roll is

required to maintain any degree of self‐control. If failed, the Keeper will dictate your Investigators

actions until he or she regains control. The list of phobias shown nearby can be converted into

philias by simply inverting them: for example, where scotophobia is a fear of darkness, scotophilia is

an obsessive and irrational predisposition to bask in darkness.

Psychogenic Fugue

Your Investigator may shut down into catatonia or wander off in an unconnected daze. It often

manifests in the face of emotional or personal complications. During acute episodes, your

Investigator may disappear for days at a time, returning with no memory of his or her recent past.

Schizoid

Your Investigator’s personality changes towards an uncharacteristic emotionlessness. He or she will

be perceived as cold or aloof by most people. This can have a devastating effect on interpersonal

relationships. In game terms, all personal interaction skill tests or CHA tests are halved; during an

acute episode such tests are made at one‐fifth chance.


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“Shell Shock”

Shell Shock (called Post‐traumatic stress disorder in more modern settings) is a psychiatric disorder

that occurs following life‐threatening events. Some people shake off such horrors, while others have

stress reactions. Victims of Shell Shock/PTSD relive the experience through nightmares and

flashbacks, have difficulty sleeping, are subject to depression, and can be overcome by anxiety when

presented with a similar situation.

<box>Phobias

ACROPHOBIA: Fear of heights

AGOROPHOBIA: Fear of open places

AILUROPHOBIA: Fear of cats

ANDROPHOBIA (for female Investigators): Fear of males

APIPHOBIA: Fear of bees

ARACHNOPHOBIA: Fear of spiders

ASTROPHOBIA: Fear of thunder, lightning and storms

BACTERIOPHOBIA: Fear of bacteria

BACTRACHOPHOBIA: Fear of frogs and toads

BATHOPHOBIA: Fear of the deep sea

BELONEPHOBIA: Fear of pins and needles

BOTANOPHOBIA: Fear of plants

CATOPTROPHOBIA: Fear of mirrors

CLAUSTROPHOBIA: Fear of confined spaces

DEMOPHOBIA: Fear of crowds

DENDROPHOBIA: Fear of trees

DORAPHOBIA: Fear of fur

ENTOPHOBIA: Fear of insects

GYNEPHOBIA (for male Investigators): Fear of females

HEMATOPHOBIA: Fear of blood

HYLEPHOBIA: Fear of forests

IATROPHOBIA: Fear of doctors

MONOPHOBIA: Fear of being alone

NECROPHOBIA: Fear of dead things

OPHIOPHOBIA: Fear of snakes

PYROPHOBIA: Fear of fire

SCOTOPHOBIA: Fear of darkness

TAPHEPHOBIA: Fear of being buried alive

THALASSOPHOBIA: Fear of the sea

TRICHOPHOBIA: Fear of hair

TRISKADEKAPHOBIA: Fear of the number 13

XENOPHOBIA: Fear of foreigners

ZOOPHOBIA: Fear of Animals </box>

Permanent Insanity An Investigator who drops to 0 SAN is effectively “lost.” Just as being reduced to 0 Hit Points

permanently removes your Investigator from your control through physical death, being reduced to

0 SAN permanently removes your Investigator from your control through insanity. Investigators

reaching 0 SAN have embraced a world of violence, helplessness, and death. No therapy or

treatment will ever bring them back.


Page 53

It remains up to the Keeper to determine when the Investigator is “removed” from play. Sometimes

it is instant; after the SAN loss, the Investigator collapses weeping and refuses to re‐engage with

reality.

Sometimes it’s more subtle. Many dangerous psychopaths get by for months or years without

detection. A player who enjoys this kind of challenge may work in tandem with the Keeper to keep

playing a character with 0 SAN for a while, pretending as though things were normal.

Usually, a character who reaches 0 SAN is either Catatonic, Delusional, or Psychopathic.

Catatonia Catatonia is complete separation. Your Investigator’s mind refuses to engage with the world that

injured it. Your Investigator no longer speaks, or eats (without prompting), or looks after him or

herself; your Investigator stares into space in a trance. Some catatonics go so deep they no longer

react to physical pain. Others rise in and out of consciousness.

Delusions Your Investigator is raving, incapable of holding a conversation that does not stray into insanity. Your

Investigator is absolutely certain of the truth of his or her delusions and acts and responds as though

they are completely real, even if that means violence. Nothing can dissuade your Investigator of

their version of reality.

Psychopathy This goes beyond ordinary sociopathy. At 0 SAN, empathy has been burned out of your Investigator.

The feelings and needs of others cannot touch him or her. People are mere objects for his or her

amusement or use. Your Investigator sometimes engages in appallingly merciless actions for

gratification. Some psychopaths with 0 SAN appear fine; they are no longer emotionally functional or

concerned with people on a human scale, but they keep a simulated veneer of civility. Many serial

killers have been classified as functional psychopaths.

Resisting Insanity It’s possible to resist SAN loss and insanity through adaptation. But suffering a trauma always comes

with a cost.

Adapting to SAN Loss People can become hardened to traumatic stimuli. What sends one Investigator fleeing may seem

mundane to an individual who has survived it often enough. Adaptation to Violence or to

Helplessness means you always succeed at a Sanity roll for that type of trauma.

Adaptation to Violence or adaptation to Helplessness occurs after your Investigator has lost SAN

from that kind of trauma three times in a row without going temporarily insane from it or hitting the

Breaking Point. You should mark your Investigator’s progress toward adaptation. Each time Violence

or Helplessness reduces your Investigator’s SAN by 1 or more, add to the tally to keep track of it. If

your Investigator suffers insanity from Violence before the “Violence tally” reaches 3, erase all the

“Violence” boxes and start again. If your Investigator suffers insanity from Helplessness before the

“Helplessness tally” reaches 3, erase all the “Helplessness” boxes and start again. If your

Investigator’s “Violence” or “Helplessness” tally ever reaches three, your Investigator becomes

adapted to that type of stressor.


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ADAPTING TO VIOLENCE: Unfortunately, being adapted to Violence means your Investigator’s

empathy suffers. He or she permanently loses 1D6 CHA and may suffer some social impacts as he or

she retreats from those around them.

ADAPTING TO HELPLESSNESS: Being adapted to Helplessness means your Investigator’s personal

drive suffers. As soon as your Investigator becomes adapted to Helplessness, he or she permanently

loses 1D6 POW.

ADAPTING TO THE CTHULHU MYTHOS: There is no adapting to the unnatural forces of the Cthulhu

Mythos. Things that exist beyond human comprehension are beyond “getting used to.” Every new

encounter is a fresh shock. The only way to “adapt” to the Cthulhu Mythos is to reach 0 SAN,

whereupon the horrors make perfect sense and no longer inflict mental damage.

EXAMPLE: In the Temple of the New Light, Professor Mason lost 6 SAN from blowing up a room full

of cultists. That sent him temporarily insane. Then he lost 1 SAN for standing up to the guard with the

Thompson Machinegun and 4 for killing a guard in self‐defense. That’s two sources of SAN loss from

violence in a row which warrants two marks on Walter’s “Adapting to Violence” tally—but at that

point he gained a new disorder. All marks were erased and the professor’s countdown to violence

adaptation reset to three.

Recovering Sanity There are only a few ways to restore mental health. These are described below.

Defeating Creatures of the Cthulhu Mythos The Cthulhu Mythos in Open Cthulhu represents such an affront to the human mind that gaining any

control over it is a sort of victory. At the Keeper’s discretion, any destruction of Mythos infiltration

by an Investigator can restore hope—and in the process, SAN.

Destroying an unnatural creature or an object known to contain otherworldly power restores an

amount of SAN equivalent to the lowest amount that could be lost for encountering it.

If the SAN loss is 1/1D6, for example, destroying it restores 1 SAN. If the SAN loss is 1D6/1D20, your

Investigator gains 1D6 SAN for destroying it.

This can mean your Investigator gains more SAN from overcoming the threat than he or she actually

lost from facing it. But it can never bring SAN higher than its maximum possible score: 99 minus your

Investigator’s rating in the Cthulhu Mythos skill.

Each Investigator who was directly involved in putting the threat down gains this SAN.

EXAMPLE: Professor Walter Mason is still trying hard to forget the horrors that he witnessed in the

Temple of the New Light. After he scrambled away from its claws, Walter unceremoniously lit his last

stick of dynamite and dropped it down into the beast’s maw – it was a hopeless gesture (with just the

base Throw skill chance) but somehow the dynamite found its home and the resulting explosion

rendered the creature a spray of glowing, blue‐green chunks. The SAN loss for facing the creature

was 1D4/1D10. Walter, laughing and screaming, regained 1D4 SAN. Vanessa rolled 3, so the good

professor’s SAN rose by 3 points.

Concluding a Dangerous Investigation Once a deadly investigation has been successfully brought to a close, all surviving Investigators can

breathe a sigh of relief that – for now at least – the world is a safer place. The Keeper is justified in

awarding such Investigators a small increase in SAN (and many published scenarios include specific


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SAN rewards associated with different levels of success). Note that, as mentioned above, such gains

can never push the Investigator’s current SAN any higher than 99 – Cthulhu Mythos.

Destroying Accounts of the Cthulhu Mythos To an Investigator whose sanity has been blasted by revelations about the horrors of the Cthulhu

Mythos, the fact that tomes exist which lay bare such secrets is disturbing. It is through such dark

volumes that the madness spreads. Accordingly, some who have lost sanity from Mythos encounters

make it their mission to track down such accounts and destroy them. What better way to protect

humanity than rid it of these dangerous traps. This, in part, explains why true written accounts of

the Mythos are so scarce.

Investigators who have experienced the Cthulhu Mythos and who deliberately destroy a Mythos

tome can earn a small boost to SAN, at the discretion of the Keeper. To qualify, the volume in

question must be an actual authentic Mythos tome and the Investigator’s actions must be

deliberate, willful, and cause the permanent and total destruction of the book. The Investigator must

also believe in the veracity of the account. The amount of SAN that can be restored by such means

depends upon the Tome’s Cthulhu Mythos bonus (see A CTHULHU MYTHOS LIBRARY, page 69).

Tome’s Cthulhu Mythos Bonus SAN gain from Destruction

+1 to +3 1D3

+4 to +6 1D6

+7 to +12 2D6

+13 to +16 2D8

+17 or more 2D10

Note that, as mentioned above, such gains can never push the Investigator’s current SAN any higher

than 99 ‐Cthulhu Mythos.

Mastery of a Skill As described on page 28, whenever an Investigator first increases his or her skill rating in a given skill

above 90% this level of mastery brings with it a sense of accomplishment and ease. There is an

associated reward of 2D6 SAN points. For obvious reasons this does not apply to the Cthulhu Mythos

skill.

Getting Help (Psychotherapy & Folk Remedies) Depending on where and when your game is set, Investigators may have the option of accessing

professional mental health services to try to overcome the ill‐effects accrued through traumatic

experiences. Prior to the mid‐20th Century, such services were very primitive and arguably more

damaging to sanity than curative. The Keeper will be the final arbiter as to whether reliable and high‐

quality psychotherapy services are available. However, even in settings where no such facilities exist

there are still ways to get help in more old‐fashioned ways.

Therapy

If your game’s setting incorporates clinical therapy, this can provide a systematic deconstruction of

the mental trauma suffered by the Investigator. Therapy is an ongoing process requiring honesty and

commitment.

Your Investigator must decide whether to truthfully tell the therapist what caused the SAN loss. If

your Investigator tells the truth, there are risks. If the SAN loss came from confronting the Cthulhu

Mythos, your therapist might diagnose your Investigator as suffering from schizophrenia.


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Alternatively, if the therapist believes your Investigator’s account, he or she may in turn lose SAN

from the shocking details they reveal. The outcomes of therapy are determined by a roll against the

therapist’s Psychoanalysis skill. If your Investigator described unnatural events and the therapist

thinks they’re delusions, that skill is halved. If the roll fumbles, your Investigator loses 1 SAN. If it

succeeds, your Investigator regains 1D6 SAN (or 6 with a critical success), up to his or her POW × 5.

If your Investigator shares tales of terrible, illegal violence and it sounds like further violence is

imminent, the therapist may report it to the authorities. Whether that happens is entirely up to the

Keeper.

If your Investigator doesn’t tell the therapist the truth, healing is limited. Make a roll against the

therapist’s Psychoanalysis skill. If it fumbles, your Investigator loses 1 SAN. If it succeeds, your

Investigator regains 1D4 SAN (or 4 for a critical success), up to his or her POW × 5.

If your Investigator suffers from a disorder, a critical success with the therapist’s roll cures it

(whether your Investigator told the truth or not). Write a note saying “cured” next to the disorder on

the character sheet—but do not erase it. The next time you gain a disorder, you must roll another

Sanity test. If that fails, the “cured” disorder returns in full force alongside the new one.

Talking it Out

In settings where there is no clinical psychotherapy there is still the time‐honored method of healing

a damaged mind through sharing one’s burden with an empathic person who one knows and trusts.

This other person might be a spiritual adviser, a folk‐psychiatrists, or just a kind‐hearted fellow

member of the community that is willing to reassure you.

Being helped through the process of recovering from mental trauma works in a similar way to

therapy although takes a lot longer and has less certain outcomes. As with therapy there are risks to

sharing detailed accounts of the events that caused the original SAN loss, both to the empathic

person (who could take SAN from the account) and to the Investigator (if the other individual alerts

others).

As with formal therapy, the effectiveness of folk remedies is determined through skill rolls against

the Psychoanalysis skill (or an alternate skill substituted by the Keeper as fits the game’s setting).

The difference is that for any benefit to be achieved, the empathic person must succeed in two

consecutive rolls.

If the Investigator has not been truthful in relating their story, they can still gain some benefit: a pair

of consecutive successful rolls will give them 1D2 SAN back (2 with a critical success), up to his or her

POW × 5. If the Investigator was truthful, the reward is 1D3 SAN (3 with a critical success), to the

same maximum.

For an Investigator to have a disorder cured through folk remedies, the empathic listener must get

two consecutive critical successes on their rolls. If that occurs, it functions in the same way to a

therapist making a critical success


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Running Open Cthulhu (Keeper Section) This section offers Keepers running Open Cthulhu several resources and suggestions to assist them

with creating their own scenarios and campaigns. It also includes rules for incorporating

supernatural forces (magic) into games of Open Cthulhu as well as the ever‐present “tomes of

mythos lore” found in Cthulhu Mythos fiction.

Customizing Open Cthulhu for Different Settings Open Cthulhu is primarily written to provide a flexible set of character options and resources to

support Lovecraftian games set in periods from the early Twentieth Century to the present day.

Obviously, these times are not the only ones in which the forces of the Cthulhu Mythos blight the

Earth; thus you may, as Keeper, find yourself running Open Cthulhu games set in different eras. This

could be tales of monastic scholars in the Dark Ages coming face‐to‐face with the hideous truth of

our reality, or it could be tales of future missions into a Universe that is dark, malevolent, and

uncaring. To run such scenarios with Open Cthulhu, the Keeper will need to make a few

customizations. Fortunately, this is generally quite easy.

There are four general steps that need to be undertaken when customizing Open Cthulhu to a new

setting or time‐period:

1. Researching the setting or period,

2. Tweaking the list of Open Cthulhu skills,

3. Defining professions which fit the setting,

4. Creating a list of available weapons (with statistics) and general equipment.

Step 1: Researching the Setting The first and most important step in customizing Open Cthulhu for a new setting is making a firm

decision about the breadth of times, places, and plots you wish the setting to support. This may

sound simple – for example, you might think you just want a “generic 17th Century setting” – but in

practice there are usually several “flavors” of a temporal setting, each providing different

opportunities for storytelling. For example, do you want your 17th Century setting to focus mostly on

urban tales of squalor in big cities like London, spy intrigue in the Royal courts of Europe, or pirate

marauding on the high seas? There is a trade‐off: choosing one or two specific story‐types will make

it easier when it comes to defining a concrete set of skills and professions (see steps 2 and 3) but will

narrow the scope that the setting can easily support. More generic concepts will cover a broader set

of scenario opportunities but run the risk that the skill and profession sets are too vague or generic.

Once you have decided on the breadth and scope of your setting, the next task is research. This can

involve tracking down texts which describe a real‐world historical period in a specific part of the

world. Alternatively, it can involve watching a selection of setting‐related movies and TV shows, or

reading some genre fiction or comics. Realistically, the more research you do the more evocative

and specific your setting will be.

It’s always a good idea when reading research material to keep an eye out for elements which have

associations with “mystery” or “problem‐solving” narratives. These are most likely to be the types of

story elements (plots, characters, places) that can be leveraged to make an Open Cthulhu tale.

Step 2: Adjusting the Open Cthulhu Skill List Based on your research into the setting, identify the types of actions or activities that are most

important to stories with a “mystery” focus occurring in that setting. Consider how well these


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character actions match with the “out‐of‐the‐box” set of skills described in DETAILED DESCRIPTION:

SKILLS on page 13. Inevitably most settings will require some tweaking of the skills list. This can

occur because:

technology in the new setting has made some skills obsolete (or relate to things not yet

invented/discovered), or

a major form of action central to the new setting is not a skill of its own, but buried deep as

a minor sub‐component in another skill.

The “out‐of‐the‐box” set of skills defined for Open Cthulhu aim to largely focus on activities likely to

be relevant to almost all settings. Physical actions like Jump, Climb, or Fist/Punch will probably fit

with most settings – past or future – as will most observational skills like Listen and Spot Hidden.

Knowledge skills, such as Chemistry or Physics, may not be relevant if the respective science or area

of study is not broadly known in the new setting. Sometimes these can be renamed to capture other,

similar, concepts such as Alchemy as a replacement for Chemistry.

The skills list has been especially designed so that skills that are inherently dependent on the

existence of specific technologies are mostly collected together as sub‐specializations of the Special

Gear skill. It is suggested that as you add and remove skills to meet the new setting’s needs, you aim

to retain that practice (e.g., if your cyberpunk setting needs a skill to operate a cyber‐hacking‐deck,

make that a specialization of Special Gear; same for your 17th Century sea captain’s skill with a

sextant). The same applies for the Drive skill, which covers a character’s ability to control a form of

man‐made vehicle – if your setting includes new types of conveyances, say a futuristic Grav‐bike, the

skill to control it should be a sub‐specialization of Drive.

A few skills may require some special attention:

Credit Rating reflects a person’s status in society, based on the assumption that the more

money or resources you have the more influential you are. This does not necessarily apply in

settings where factors other than wealth determine social standing. In those settings it may

be preferable to rename the Credit Rating skill to “Status” or something similar.

Electrical Repair obviously only applies in settings where electricity has been adopted as a

general means of powering a large variety of devices. If this is not the case for your setting,

consider removing or renaming the skill. The same applies to Operate Heavy Machinery

(intended to cover large‐scale industrial mechanisms). Mechanical Repair is also similar,

although the reliance on mechanical tools and simple mechanisms is prevalent through most

historical eras, right back to the cavemen.

Psychoanalysis as a discipline is not known prior to the early Twentieth Century, however

the ability to treat a broken mind via folk remedies or counsel go back almost to the dawn of

civilization. For settings where the name “psychoanalysis” doesn’t make sense, consider

retaining the skill but under a different name.

When editing the skill list, try to avoid drastically changing the number of skills and sub‐

specializations. The number of skill points available to each character during Investigator Generation

doesn’t change from setting to setting, thus a skills list which has twice the number of available skills

forces players to spread the same points over more skills – this leads to weaker or hyper‐specialized

characters. Conversely, dividing the skill points over a set of skills with just a handful of options will

lead to much more powerful characters.


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It is often a good idea to tackle the development of a revised skills list for the new setting hand‐in‐

hand with the development of profession types (see next step).

When creating brand new skills, you will need to also define a base rating for each skill. This should

be the skill rating possessed by the average basically‐educated member of the community; it

shouldn’t reflect the skill level of a specialist or expert, but neither should it reflect the proficiency of

a dunce.

In some settings, it may be necessary to revisit the base ratings for skills retained from the “out‐of‐

the‐box” list, to reflect the norms of the new setting. Whereas it might be fine to assume that a

Twentieth Century or modern Investigator has a default 25% in Swim, that probably doesn’t make

sense for Investigators living in an arid Post‐Apocalyptic setting where the oceans boiled away

centuries ago. Adjust the base ratings to fit your conception of the average individual in the setting.

Step 3: Creating New Professions The core part of any Open Cthulhu game is the Investigators. Their role is to be the protagonists in

the story and take on the big challenges to solve key mysteries and unearth hidden horrors. The list

of professions described in the table on Page 11 are well‐suited to Twentieth Century and modern

tales of mystery‐busting but would seem anachronistic or ill‐suited to many other settings. For this

reason, it is important to consider what types of Investigator professions you envisage in your new

setting.

It’s perfectly possible to “cherry‐pick” some professions from the “out‐of‐the‐box” list as being

appropriate to your new setting – perhaps the concept of a Police Detective works fine in your idea

of a Blade‐Runner‐esque future noir setting. When transferring professions across like this, take

some time to look through the list of professional skills and replace any that do not feature in the list

of skills you developed in the previous step. In general, it’s worthwhile trying to replace skills with

similar or functionally‐analogous skills. For example, if a deleted professional skill was a knowledge

type skill, replace it with another knowledge skill. It is usually not desirable to remove a skill without

replacing it – each profession should have eight professional skills (or option slots), to retain a level

of flexibility to Investigator creation.

In cases where a brand‐new profession type is needed, you will need to:

Choose a suitable name for the profession, and

Pick eight skills that are especially important for members of that profession (noting that

one or two of those skill “slots” can be left as personal specialties which the player can pick

during Investigator generation).

To develop a list of professional skills, you can simply scan through the skill list you developed for the

new setting and pick out the ones that seem logically associated with the profession. In practice, this

can sometimes be difficult because the number of potential choices can seem overwhelming. In such

cases, it is sometimes helpful to consult or remix the “character archetypes” (which are deliberately

generic) described in the nearby box.

<box>Creating New Professions using Archetypes The term “archetype” is used here to describe a generic and broad category of characters that might

turn up in any story, irrespective of where it is set. They aim to capture semi‐immutable functions of

plot or human society that apply to most eras and environments.


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You can use these archetypes as helpful building blocks to develop a new profession. There are two

ways of doing this:

1. You can simply pick one archetype that seems closely aligned to the profession you want to

develop (e.g., perhaps you consider your new pre‐historic “tribal wise woman” profession to

be a kind of “Knowledge Source”). In this case, you should ensure that all of the skills

labelled “(must)” form part of your new profession’s dedicated skill list. Some or all of the

skills in the list labelled “(might)” could also appear as professional skills; you should choose

based on your concept for the profession. If the resulting list of professional skills is less

than eight, add some additional skills of your own devising (or leave the slots open to player

choice as “personal interests”).

2. You can decide that the new profession is the intersection of two of the archetypes listed in

the table (e.g., perhaps you consider the pre‐historic “tribal wise woman” to instead be a

fusion of “Knowledge Source” and “Healer”). In this case, the professional skill list for the

new profession should include all the “(must)” skills for *both* archetypes, and can be filled

out with skills chosen from the “(might)” skill list for either or both archetypes. The total

number of skills in the new profession’s skill list must equal eight (inclusive of any player‐

choice slots you wish to include).

Note that the Archetype descriptions below mention a mixture of actual concrete skills (e.g., Climb)

and categories of skills (“a Social skill”). If a concrete skill doesn’t exist in the list of skills defined for

your setting either ignore it or replace it with a similar skill. The grouping of skills into broad

functional categories is described at the end of the list of Archetypes. This grouping is based on the

“out‐of‐the‐box” skills; they will need to be updated to match the skills list defined for your new

setting. Note that this categorization scheme is only used for Archetype definition and has no

bearing on any other aspect of the Open Cthulhu rules.

Archetype Template: Administrator

Professional Skills (must): Accounting, Law, an Information skill.

Professional Skills (might): Spot Hidden, Persuade or Fast Talk, a Communications skill, a Social skill

+ any one skill as a personal specialty.

Archetype Template: Explorer

Professional Skills (must): Climb, Navigate, a Physical skill.

Professional Skills (might): Jump, Ride, a Conflict skill, a Communications skill + any one skill as a

personal specialty.

Archetype Template: Healer

Professional Skills (must): First Aid, Medicine, a Social skill.

Professional Skills (might): Natural History, Psychology, two Information skills + any one skill as a

personal specialty.

Archetype Template: Knowledge Source

Professional Skills (must): Library Use, two Information Skills.

Professional Skills (might): History, Other Language, Own Language, a Social skill + any one skill as a

personal specialty.


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Archetype Template: Leader

Professional Skills (must): Persuade, Psychology, a Social skill.

Professional Skills (might): Fast Talk, Law, an Information skill, a Communication skill + any one skill

as a personal specialty.

Archetype Template: Muscle

Professional Skills (must): Dodge, Throw, a Physical skill.

Professional Skills (might): Fighting (Fist/Punch, Head Butt, Grapple, or Kick), Track, a Physical skill, a

Subterfuge skill + any one skill as a personal specialty.

Archetype Template: Protector

Professional Skills (must): Fighting (Fist/Punch, Head Butt, Grapple, or Kick), Psychology, a Conflict

skill.

Professional Skills (might): Dodge, Sneak, a Conflict skill, a Subterfuge skill + any one skill as a

personal specialty.

Archetype Template: Resource Procurer

Professional Skills (must): Accounting, Bargain, a Communications skill.

Professional Skills (might): Persuade, Spot Hidden, an Information skill, a Conflict skill + any one skill

as a personal specialty.

For the purposes of these archetype templates (and these only), the following categorization of

“out‐of‐the‐box” skills exists:

Communications Skills are: Other Language, Own Language, Listen.

Conflict Skills are: Dodge, First Aid, Fist/Punch, Head Butt, Grapple, Kick, Martial Arts, Melee

Weapon, Ranged Weapon, Throw.

Information Skills are: Accounting, Anthropology, Archaeology, Astronomy, Biology,

Chemistry, Geology, History, Law, Library Use, Natural History, Occult, Pharmacy, Physics,

Spot Hidden.

Physical Skills are: Climb, Jump, Navigate, Ride, Swim.

Social Skills are: Art, Bargain, Credit Rating, Fast Talk, Persuade, Psychoanalysis, Psychology.

Subterfuge Skills are: Conceal, Electrical Repair, Hide, Listen, Locksmith, Sneak, Track.

Technical Skills are: Drive, Electrical Repair, Mechanical Repair, Medicine, Operate Heavy

Machinery, Pilot, Special Gear.

EXAMPLE: Larissa is developing Ancient Greece as a new Open Cthulhu setting; she has read several

fiction and non‐fiction books, and based on that she likes the idea of creating a “Greek Sage” as a

profession type. These, historically, were a type of philosopher that also achieved a level of

statesman like power (in some cases). Based on this, Larissa thinks perhaps she can use both the

“Knowledge Source” archetype and the “Leader” archetype as the basis for the Greek Sage. The skills

listed in the profession list for the Knowledge Source suggests that the Greek Sage professional skill

list must include Library Use (or equivalent) and two Information Skills; the list for Leader suggests

that the Greek Sage professional skills list must also include Persuade, Psychology and one Social

Skill. Together, that fills up six of the eight skills slots needed for the new profession. Larissa chooses

two Information Skills which seem appropriate (Astronomy and Philosophy, the latter a new skill

addition she has made for this setting) and one Social skill (Status; an analogue which Larissa chose


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as a replacement for Credit Rating in her setting). Larissa has two slots left to fill and has the two lists

of “(might)‐have” skills, to choose from. She picks History from the Knowledge Source list and Law

from the Leader list.

After this process of selection, Larissa is left with a professional skill list for her Greek Sage which

reads: Astronomy, History, Law, Library Use, Persuade, Philosophy, Psychology, Status.

</box>

Step 4: Available Weapons and Technology The last step in customizing Open Cthulhu for a new setting is developing a list of the types of

equipment and/or technology that is potentially available for Investigators to purchase or otherwise

acquire. This is an important step in bringing the setting to life – but one which is entirely dependent

on the specifics of the setting being developed. Your research should give you an excellent launching

point for developing this list – even if it begins simply as a list of devices and equipment mentioned

in the historical and/or fictional sources consulted.

In general, there is no specific need to develop detailed game mechanics associated with pieces of

equipment. The big exception to this is for weapons and, to a lesser extent, armor. For the former

you will need to develop game statistics similar to those found in the weapons tables beginning on

Page 39. You can use the examples found in those tables as a general guideline to how to describe

different types of normal and lethal weapons. For armor, there are two basic decisions – what armor

rating does it possess, and (if a futuristic type) whether it has some effect to modify Lethal damage

in some way.

H.P. Lovecraft’s Dreamlands While H.P. Lovecraft is most famous for his tales of supernatural horror set in the (real‐world) 1920s

and 1930s, he also wrote other fiction which has a more ethereal and dreamlike setting. These

fabulous stories are set in “Earth’s Dreamland” – a place beyond our physical Universe, a set of

mental realms created by the collective unconscious of dreaming humans. Keepers who are

interested in a distinct change of narrative style for their Open Cthulhu campaign might choose to

set some or all of a scenario in this fantastic realm. The notes below provide some basic information

about how the Open Cthulhu rules work in a land made from dreams.

Tone of Dreamlands Adventures The best way to get an appreciation of the general feel of Earth’s Dreamlands is to read Lovecraft’s

original fiction cycle which describes it. The following stories make up that cycle:

The Dream‐Quest of Unknown Kadath [a key source] (1927)

The Silver Key (1926)

The Cats of Ulthar (1920)

The White Ship (1919)

Celephaïs (1920)

The Other Gods (1921)

Polaris (1918)

The Quest of Iranon (1921)

Hypnos (1922)

The Doom That Came To Sarnath (1919)


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These stories are infused with an atmosphere of dream‐like wonder, with fantastic cities and beasts

roaming spectacular and vibrant lands. The inhabitants of these realms fall into two categories –

those who are permanent residents of the dream world, and those who are the dream‐forms of

people who are currently sleeping on Earth, experiencing the realm through interactive dreams.

Entering the Dreamlands In general, humans can only enter the realms of Earth’s Dreamlands through their dreams – a kind of

mental travel to a place which has a type of perceptual reality but is beyond our physical Universe.

Some people are born with a natural gift for being able to will themselves into the special type of

dream state that can initiate travel to the Dreamlands. Others learn this skill through long years of

tuition or self‐practice. Yet others seek to short‐cut the process through the use of special drugs.

In very rare cases, some people find themselves physically transferred to the ephemeral realms of

dream, usually as the result of magic or via arcane gateways. This means of experiencing the

Dreamlands is far more dangerous, since those physically inside the dream reality cannot simply be

extricated via their waking selves being awoken – they typically can only return to Earth via some

reciprocal gateway or magic.

While within the Dreamlands – either as a dream traveler or via physical transfer – time passes at a

vastly different rate to how it does on Earth. A week within the dream might only take an hour in the

real world. This relationship is not necessarily constant – like everything else in a dream it can

change without warning or logical reason.

Leaving the Dreamlands Generally, for those adventuring in Earth’s Dreamlands, their time in the dream realms will be

determined by the needs of the scenario. When their goal has been achieved they will awaken in

their physical bodies. Some lengthy dream‐quests might require several visits – in such cases, the

dreamer awakens at a specified point, and may return to the dream simply by going to sleep the

next night. Such serial dream episodes always pick up exactly where the prior night left off.

Each time someone leaves the dream by awakening, there is a chance that they will not clearly

remember the details of their dream. Each Dreamer should attempt an INT roll on waking – failure

means he or she does not retain clear memories of what transpired. Such individuals will not

remember any important information learned while in the Dreamlands, and any checkmarks against

skills (apart from Dreaming and Dream Lore; see below) gained during the dream session are erased.

If a Dreamer’s sleeping physical body is disturbed in the real world, this may trigger an early

awakening. The dream‐self of the person senses the pull of reality and can attempt to resist it

through a successful INT roll (perhaps penalized according to the severity of the events occurring in

the real world).

There may be reasons why a Dreamer may want to will him‐ or herself awake to voluntarily

terminate their journeys in the Dreamlands. Normally this is not possible, although there are certain

Nightmarish Twists (see the table on page 65) which can abruptly cause a person to be ejected from

the dream. When a character leaves the Dreamlands, other Dreamers who remain see their

colleague simply fade from existence. Permanent residents of the Dreamlands consider this a

perfectly natural phenomenon.

Reality in the Dreamlands When running scenarios in Earth’s Dreamlands there are a handful of differences that a Keeper will

need to introduce.


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The first of these is that the dream reality cannot accommodate modern technology –

characters who are dreaming while their physical forms bear technical devices (including

weapons) will find themselves arriving in the Dreamlands with analogous items from the

time of Earth’s Dark Ages.

Dreaming characters may learn two new skills which will assist with their navigation of the

realms of dream. These are described in the nearby box. Furthermore, when their dream‐

selves take physical or mental damage it is handled in a slightly different way to normal.

<box>New Skill: Dreaming The physical “reality” of Earth’s Dreamlands is far more malleable than the normal waking world we

are used to. Indeed, experienced dreamers can deploy their skill in Dreaming to twist and warp the

dream world to their specification.

The first time an Investigator enters Earth’s Dreamlands he or she receives the Dreaming skill with a

starting skill rating equal to POW.

At any time thereafter, a dreaming Investigator may attempt to change some detail of the

Dreamlands “reality” according to his or her will. Such attempted changes can be either small (e.g.,

turning a simple tankard into a bejeweled goblet) or they can be more significant (e.g., turning a

modest dwelling into a richly appointed mansion). Especially vast changes (like crafting an entire city

from nothing) can be attempted by particularly skilled Dreamers, but these are typically treated as a

long series of smaller changes to Dreamlands “reality,” each of which will require time, effort, a

sacrifice of Magic Points (see below) and a roll against the Dreaming skill.

Each attempt to employ the Dreaming skill requires that the player describe the desired effect and

(based on this) a determination by the Keeper as to the number of Magic Points required to make it

happen. Typically, smaller changes might cost 1‐6 MPs, while larger ones might cost 10 or 20 or even

more points at the Keeper’s discretion. If the Dreamer sacrifices the right number of Magic Points he

or she can attempt a roll against the Dreaming skill. If successful, the change occurs. If the roll fails,

no change occurs but the Dreamer still loses the Magic Points.

The Dreaming skill advances the same as any skill – after a successful roll, the Dreamer can check the

skill and roll for improvement at the end of the scenario.

New Skill: Dream Lore Despite its malleability, the lands of Earth’s Dreamlands have a somewhat defined geography and

culture. There are well‐known places, kingdoms, and peoples. Knowledge of these details is covered

by the Dream Lore skill. When first entering Earth’s Dreamlands an Investigator gains this skill with a

starting skill rating of half his or her Cthulhu Mythos skill. It advances like any other skill, through

experience checks.

</box>

Taking Damage When Dreamers get into peril or combat in Earth’s Dreamlands they may take damage. The

Dreamer’s virtual dream self begins the dream journey with a number of Hit Points equal to his or

her physical body, even though that body is asleep in a dimension far away. When the Dream form

takes damage, Hit Points are lost from the dream body, but do not directly affect the sleeping

physical body.


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If the Dreamer wishes to attempt to use the Dreaming skill to heal damage inflicted to his or her

dream form, a sacrifice of 1D3 Magic Points per Hit Point lost must be made before the roll can be

attempted.

If the dream form’s Hit Points ever reach zero – that is, the Dreamer “dies” within the Dreamlands –

his or her journey within the dream realms is over. Such individuals instantly suffer a Nightmare

Twist of Reality (see the box nearby), take an additional 1D10 loss to Sanity Points (in the real world),

and find themselves shocked awake in their beds. If the events leading to the Dreamer’s demise

were especially traumatic, the Keeper may rule that the “death” means that the Investigator can

never again reach Earth’s Dreamlands.

If somehow the sleeping form of the Investigator dies in the real world while his or her

consciousness is travelling in the Dreamlands, there is a chance of passing over to become a

permanent resident of the Dream. If the Investigator desires such an eternal afterlife, success with a

Dreaming skill roll can make it happen.

Sanity Losses Unlike the separate pool of dream‐form Hit Points and real‐world Hit Points, the Sanity Points of the

real and virtual forms are directly linked. If Sanity Points are lost while journeying in Earth’s

Dreamlands, the loss is deducted from both the sleeping real‐world form and the dream form.

If a Dreamer loses more than five points of Sanity in a single encounter, and also fails an INT × 5 roll,

he or she immediately experiences a Nightmarish Twist of Reality (see the table nearby). This

mechanism replaces the normal rules for temporary insanity.

If a Dreamer is ever reduced to zero Sanity Points, he or she suddenly wakes in the real‐world,

screaming and incoherent, and hopelessly (and permanently) insane.

<box>Nightmarish Twists of Reality When a Dreamer suffers a terrible shock in the Dreamlands, he or she experiences a terrifying

alteration to the reality surrounding them. The Keeper can either roll a 1D10 and consult the

following list or pick something that seems appropriate to the situation.

1 An item being carried by the Dreamer, or perhaps a small part of his or her body, warps to take on a horrific form. This change is permanent for the duration of this dream session, but can be reversed by use of the Dreaming skill (as long as a number of Magic Points is expended equal to the Sanity loss triggering the Nightmarish Twist).

2 The Dreamer suddenly finds himself or herself powerless to escape from the horror that triggered the Nightmarish Twist. This might be because the walls have altered to box them in with the horror or may just involve the individual being inexplicably paralyzed. This effect lasts until the threat is eliminated or removed.

3 The Dreamer sees the world around them dissolve, and suddenly finds themselves somewhere entirely different in the realms of Earth’s Dreamlands. This forced relocation can be reversed by use of the Dreaming skill (as long as a number of Magic Points is expended equal to the Sanity loss triggering the Nightmarish Twist).

4 Either an NPC travelling with the Dreamer, or a domestic creature in the vicinity of the Dreamer, is inexplicably transmuted into a horrifying monster. This is most likely to be a similar terror to whatever triggered the Nightmarish Twist. This change can be reversed by use of the Dreaming skill (as long as a number of Magic Points is expended equal to the Sanity loss triggering the Nightmarish Twist).


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5 A would or injury that has previously plagued the Dreamer, but has long been healed, mysterious reappears on his or her body. This change can be reversed by use of the Dreaming skill (as long as a number of Magic Points is expended equal to the Sanity loss triggering the Nightmarish Twist).

6 The Dreamer suddenly has a sense that he or she has woken up, but still finds themselves in the Dreamlands. It is almost as if this place is now their reality. This experience is profoundly disconcerting, and for a period of time the Dreamer is considered disoriented and cannot navigate around without direction from other people. The length of this befuddlement is at the Keeper’s discretion; it can also be ended through the successful application of the Psychoanalysis skill.

7 The Dreamer must immediately make an opposed test comparing their INT against the Sanity Point loss triggering the Nightmare Twist. If the roll is unsuccessful, the Investigator instantly awakens back in the real world but their hair has inexplicably turned grey or white, or has begun falling out.

8 The Dreamer must immediately make an opposed test comparing their POW against the Sanity Point loss triggering the Nightmare Twist. If the roll is unsuccessful, the Investigator instantly awakens with a permanent nervous tic, chosen by the Keeper. If the tic is highly visible, it may also cause a loss of CHA or DEX by 1D3 points.

9 The Dreamer must immediately make an opposed test comparing their CON against the Sanity Point loss triggering the Nightmare Twist. If the roll is unsuccessful, the Investigator instantly awakens in the midst of a minor heart attack. He or she must immediate make a percentile roll under CON × 10 or die. Even if the roll is successful, 1 permanent point of CON is lost.

10 Keeper’s choice of nightmarish effect. In general, if the effect is something that applies to the Investigator’s sleeping real‐world body, it should cause him or her to immediately awaken. Alternatively, if it is a transformation of their dream body the Dreamer should have the opportunity to reverse it through the application of the Dreaming skill (and the sacrifice of an appropriate number of Magic Points).

</box>

Magic and Tomes The fiction of H.P. Lovecraft and other Mythos writers portray a version of our world in which

powerful supernatural forces exist. These can be manipulated by (typically insane) practitioners of

Mythos “magic” to bring about certain changes in the physical world or within the minds of others.

Whether such forces are truly “spells” in the Hermetic or Alchemical tradition, or a type of advanced

physics or mathematics, is largely irrelevant – they are forces which modern man simply cannot

understand or reliably predict.

Another staple of the genre is Mythos Tomes – incredibly rare and suppressed volumes which

expose some of the secrets of reality’s true nature, and the foul influences of the Cthulhu Mythos

and its associated magic.

As an Open Cthulhu Keeper, you may wish to incorporate Mythos magic or Tomes into your games of

Investigative cosmic horror. The guidelines below give a simple means of doing so – however, do not

treat them as immutable “rules” which cannot be altered to suit the circumstances of a particular

scenario or campaign. Magic by its definition is unknowable, thus can manifest in inconsistent and

unpredictable ways. Similarly, Mythos Tomes are rare and multi‐faceted things: Investigators who

stumble upon one may have discovered a trove of useful knowledge, or a mostly‐ruined expurgated


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copy which tells them little. The way such elements work in the game should be driven by the

underlying scenario plotline more than any hard‐and‐fast game statistics.

Tomes of the Mythos In the fiction of H.P. Lovecraft, it is not uncommon for reference to be made to legendary tomes of

knowledge which explain some of the secrets of the Mythos. The most famous of these is The

Necronomicon. Such tomes can also play a part in your Open Cthulhu scenarios, either serving as a

method for Investigators to improve their knowledge of the hidden truths of reality or providing

motivation for insane human adversaries.

Knowledge of the true nature of reality, and the part which Cthulhu and his ilk play in it, is inherently

dangerous. So too is knowledge of the spells and rituals which permit contact with forces of the

Mythos. The human mind inherently recognizes such things as inimical to sanity and perilous to

commit to paper. However, over the centuries there have been certain insane authors, translators

and publishers who have nevertheless produced books which contain such information, albeit

usually in a cryptic and hidden way. These are the tomes of the Cthulhu Mythos.

In Open Cthulhu, Mythos Tomes provide Investigators with the opportunity to improve their

knowledge of the Cthulhu Mythos as well as potentially learn Mythos spells or rituals. They can also

be helpful references when trying to understand the nature of a Mythos threat. On the flip‐side,

anybody who spends long hours poring over such books will almost certainly lose Sanity. They may

also attract the attention of groups of ruthless and insane people who will stop at nothing –

including murder – to get their hands on such rare and powerful books.

Reading a Tome Researching a Mythos Tome is a significant investment of time and is usually an activity that an

Investigator will attempt in the “downtime” between scenarios. Fully researching the tome – reading

it, understanding it, seeing through any cryptic allusions, and comprehending the significance of

what is being implied – usually takes 2D6 game months. The research represents an intensive period

of study but does not need to be consecutive.

For an Investigator to benefit from the research, he or she must satisfy two pre‐requisites:

1. Have a Cthulhu Mythos skill above zero and succeed in an Immersion Roll (see below),

and

2. Have a language skill in whichever language the Tome is written (or access to a skilled

translator) and succeed in a language skill roll.

If both of these conditions are met, and the requisite months of study are completed, the researcher

will gain percentiles in the Cthulhu Mythos skill (representing the secrets he or she has learned). At

the same time, Sanity Points will be lost.

The Immersion Roll

To the layman, a Mythos Tome looks like nothing more than a random collection of disjointed

thoughts, none of them imparting any real meaning. This is because most people have no prior

experience of the Cthulhu Mythos and thus have no reason to think that the gibbering ravings might

be something meaningful.

If the Investigator undertaking the research has a zero skill rating in Cthulhu Mythos, he or she will

be likewise unconvinced. Such an individual will be unable to become sufficiently ‘immersed’ in the

Tome’s buried secrets to learn anything useful.


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On the other hand, a researcher with skill in Cthulhu Mythos may be able to see past the obvious

rantings and perceive the implied secrets. This requires an Immersion Roll: an Opposed Test (see

OPPOSED TESTS on page 26) which pits the researcher’s Cthulhu Mythos skill × 10 against the

Cthulhu Mythos rating of the book × 5. See the table on page 69 for game stats for several Tomes.

If this roll fails, the researcher becomes convinced that the Tome is a fake; no matter how many days

or weeks he or she invests in studying it that belief will prevent any deeper understanding.

EXAMPLE: Professor Walter Mason returns to the Temple of the New Light and quietly breaks in,

discovering their sacred library of texts. Amongst these moldy old volumes, Walter discovers a copy

of the Latin translation of the Necronomicon, which he recognizes by its dark reputation. He pockets

the book. Days later – after the professor and his associates have put paid to the evil plans of the

New Light cult – Walter decides he would like to study the Necronomicon which he suspects is a

Cthulhu Mythos Tome. Sam the Keeper makes a roll to determine how long the full research project

will take: her 2D6 roll is 7, so a full study of the volume will take Walter seven months of game time

(which can be spread among several blocks, for example between adventures). Sam doesn’t tell

Vanessa how long the process will take but does ask her to make an Immersion Roll to see if Walter

can see beyond the apparent gibberish of Olaus Wormius’ Latin text. The professor’s Cthulhu Mythos

skill is 6% and the Latin Necronomicon has a Cthulhu Mythos rating of +16. That means the opposed

test will be comparing Walter’s Cthulhu Mythos × 10 (60) against the book’s Mythos Rating × 5 (80).

Vanessa rolls a D100 for Walter at the same time as Sam rolls a D100 for the book. Walter’s roll is 41

– a standard success; Sam’s roll is 10 – also a standard success. Since Walter’s roll is higher than the

book’s, he wins the opposed test. Thus, Walter will become immersed in the book and can see

beyond the confusing detail of Prinn’s cryptic allusions … perhaps to his peril.

The Language Roll

To comprehend the meaning of a Mythos Tome, the researcher will always require a successful roll

against his or her applicable Language skill. If the volume is written in the same language that the

researcher speaks, the test is against Own Language; otherwise it is against an appropriate Other

Language skill. The difficulty of this skill test is decided by the Keeper, depending on how complex

the text and how arcane its allusions.

If the researcher has no skill in the language, he or she can engage the services of a translator. This

can prove difficult if the translator does not comprehend the deeper meaning of the text.

If the translator has no experience of the Cthulhu Mythos, his or her language test will be

halved; or

If the translator has some Cthulhu Mythos skill and can make an Immersion Roll (see above)

then the language test is normal; if the translator has Mythos knowledge but fails an

Immersion role, his or her language test will be halved.

If the language roll succeeds, the research project is ultimately successful once the necessary

amount of time (as rolled by the Keeper at the beginning) has been expended.

If the language roll fails, the complexity of the text has proven too much. The time invested has been

wasted with no beneficial outcome. The researcher has still understood enough to lose half the

book’s Sanity penalty (as per skimming, see page 70), but does not earn any skill percentiles and

cannot attempt to learn any spells.

A failed researcher cannot re‐attempt to read the same Tome until his or her skill in the relevant

language has increased by at least ten percentiles (or a translator can be engaged who has a skill


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rating at least ten percentiles higher than that used in the previous test). In any case, a subsequent

attempt must go through the entire process again (including another Immersion roll) and will take

another 2D6 months.

Rewards of Research

Once the tome has been successfully researched, the researcher immediately gains a number of

percentiles in Cthulhu Mythos equal to the book’s Cthulhu Mythos Rating (see the table on page 69

for some examples).

At the same time, the researcher will lose Sanity Points as per the book’s stated Sanity Loss. If this

loss pushes the researcher below his or her Breaking Point, the experience of reading the book will

cause a break‐down during which he or she develops a new disorder (see DISORDERS on page 49).

If the research project involved a translator, the Keeper may rule that this individual also suffers a

loss of Sanity and a gain of Cthulhu Mythos percentiles although this is likely to be only a fraction of

the full amount.

EXAMPLE: Professor Walter Mason has spent weeks and weeks researching his Latin Necronomicon

– devoting all free moments in between adventuring. Sam, the Keeper, asks for a roll against

Walter’s Other Language (Latin) skill. The professor is highly proficient in Latin, having a skill rating of

70%. Sam rules, that although Olaus Wormius’ text is cryptic Walter’s skill test will be at normal

difficulty. Vanessa rolls a 49 – success. After Walter has reached the point of having expended 7

combined months in researching the book he will understand it fully. At that point, he immediately

gains 12 percentiles in Cthulhu Mythos and suffers a Sanity loss of 1D6/2D6. Walter’s Sanity is 35 and

his Breaking Point 24; he fails his SAN roll and loses 10 SAN. This is enough to invoke a few moments

of temporary insanity at key moments during the seven‐month research project, which may have

been remarked on by his colleagues, but he has (narrowly) avoided picking up a new disorder.

A Cthulhu Mythos Library Described below are a sample of some of the Cthulhu Mythos Tomes that are mentioned in the

writings of H.P. Lovecraft. The table nearby shows game statistics for each; note that some books

exist in multiple translations and different editions.

<box>Game Stats for Selected Mythos Tomes

Tome Language Author/Trans. Published Sanity Loss Cthulhu Mythos

Spell Mult.

Necronomicon, Al Azif (original manuscript)

Arabic Abdul Al‐Hazred c. 730 1D10/2D10 +18 ×5

Necronomicon, Greek Greek tr.Theodoras Philetas

950 1D10/2D10 +17 ×5

Necronomicon, Latin Latin tr. Olaus Wormius 1228 1D10/2D10 +16 ×5 Necronomicon, English English tr.Dr. John Dee 1586 1D10/2D10 +15 ×4 Necronomicon, partial: “Sussex Manuscript”

English tr.Baron Frederic 1597 1D3/1D6 +7 ×4

Book of Dzyan English unknown Pre 19th Cent. 1D3/1D6 +9 ×1 The King in Yellow English tr. unknown c. 1895 1D3/1D6+1 +5 no

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The Necronomicon

The most famous and iconic of Mythos tomes, the Necronomicon was penned by the mad Arab,

Abdul Al‐Hazred, and contains the secrets of elder Earth. The original text is written in Arabic, but

Greek, Latin, English, and French translations exist.

Book of Dzyan

Written primarily in Sanskrit and Chinese, the first sections of the Book of Dzyan are written in an

unknown language, purportedly being angelic or extraterrestrial in nature. The earthly sections are

Buddhist commentary on the nature of the Mythos.

The King in Yellow

Hidden within the lines of this accursed play are hints at the nature of the Yellow King and Carcosa.

The text seems to work on a subliminal level and has been known to drive readers insane. Written in

French with English translations, the banned, original edition was bound in snake skin.

Skimming a Tome Thoroughly reading a Mythos Tome is a major investment in time. However, Investigators may wish

to quickly skim through the book to get a basic understanding of what it contains. Skimming a Tome

normally takes a number of hours equal to the Cthulhu Mythos Rating ÷ 3. Skimming always

succeeds as long as the person reading the book has at least 1% in the requisite language skill.

If the individual skimming the book has zero Cthulhu Mythos skill or fails in an Immersion Roll (see

page 67), he or she concludes that the book is worthless.

Otherwise, the skimming individual gains a general appreciation of the contents of the book. He or

she suffers half the Tome’s Sanity Loss but gains no points of Cthulhu Mythos and no ability to learn

spells. If the same individual later succeeds in fully comprehending the book (through detailed

research) the amount of SAN lost during that experience is reduced by the amount previously

suffered for skimming the book.

<box>Getting Started with the Cthulhu Mythos Skill Investigators start play with zero percentiles in the Cthulhu Mythos skill. As described in this section,

such an individual cannot ever successfully research a Mythos Tome. How then can a new

Investigator increase his or her Cthulhu Mythos away from zero? The answer is through first‐hand

experience of the Mythos in action. As described in UNDERSTANDING THE CTHULHU MYTHOS on

page 48, each time an Investigator suffers a bout of Temporary Insanity or develops a mental

disorder through encountering a Mythos threat, at least one point of Cthulhu Mythos skill is gained.

Once the Investigator has internalized these experiences, he or she will start to look at Mythos

Tomes differently, and potentially learn further Cthulhu Mythos knowledge by researching them.

</box>

Using Mythos Tomes as Reference If an Investigator has read and fully comprehended a Mythos Tome, then he or she can potentially

use it as a reference to answer questions about the nature of the Cthulhu Mythos that arise during a

scenario. In such cases, the Keeper can ask for a 1D100 roll below the book’s Cthulhu Mythos rating

× 5 to determine whether the required detail is mentioned. If the desired information is highly‐

specialized or obscure, the Keeper may decide the roll should be against the book’s Cthulhu Mythos

rating × 3 or even Cthulhu Mythos rating × 1.


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Learning Spells from a Tome Some Mythos Tomes contain descriptions of rituals and incantations which can allow a human being

to attempt contact with the forces of the Cthulhu Mythos. These are generically termed “spells”.

If a Mythos Tome contains one or more spells, and an Investigator has fully researched the book he

or she may then proceed to attempt learning the spells. Each attempt to learn a spell takes 2D6

weeks and requires the Investigator to make a 1D100 roll below his or her INT multiplied by the

book’s spell multiplier (see the table on page 69 for some examples).

If the test is successful, the Investigator has leaned the spell and may attempt to perform the

necessary ritual. If the INT test fails, the time has been expended in vain. The Investigator may make

another later attempt to learn the same spell.

Note that each spell must be learned separately, and each requires a period of 2D6 weeks study to

master.

A representative grimoire of Cthulhu Mythos spell may be found starting on page 110.

Casting Spells As an Open Cthulhu Keeper, you may wish to present scenarios which feature manifestations of

Mythos Magic: these might be powerful “spells” known by adversaries of the Investigators … or you

may permit erudite Investigators to themselves learn certain magical rituals from Mythos tomes. In

either event, the following guidelines and rules will help in your depiction of how magic “works” in

the game world.

General Principles of Mythos Magic Magic in Open Cthulhu is quite unlike the forms of magic that appear in most Roleplaying Games,

especially games set in the Fantasy genre. In those games, a sorcerer might wield a flashy fireball

into the midst of combat – while in Open Cthulhu, a typical spell might be an hours‐long ritual

incantation which places the sorcerer’s mind into communion with an extradimensional horror from

Beyond.

The following general guidelines will help you in depicting magic in a suitably low‐key and creepy

fashion:

Magic is seldom flashy: while some spells might create a spectacular if shocking

manifestation of unnatural horror, most work with little or no visible or physical effect.

Frequently, casters of Mythos magic have no way to tell whether their ritual succeeded or

not until hours, days, or even weeks after it finishes. And even then, its effects may be

subtle changes that most people would never notice.

Magic is usually time‐consuming to cast: most Mythos spells take the form of long‐winded

rituals which are repetitious and wearying to perform. While there are a handful of spells

which might be useful in a tactical, fast‐paced situation, most play out far too slowly to help

in such situations.

Magic is ALWAYS dangerous to access: casting a Mythos spell is equivalent to opening

one’s mind and essence to the unknowable forces which make up the Cthulhu Mythos.

These powers are inherently corrosive to reality as we know it, so coming into direct mental

or physical connection with them always causes some form of lasting damage to the

spellcaster, and maybe others as well.


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Magic is the enemy of Sanity: For the same reasons described above, connecting with the

forces of the Cthulhu Mythos is inherently dangerous to one’s Sanity. In game terms this

manifests as a mandatory sacrifice of SAN; but in narrative terms you should play up the

highly disturbing experience of touching an unknown and unknowable extra‐dimensional

force whose very existence is anathema to everything that the caster has ever known or

experienced. Casting spells should hurt, every single time.

Fueling Mythos Rituals and Spells Each spell description (see GRIMOIRE OF MYTHOS SPELLS, starting on page 110) describes the

amount of Magic Points and Sanity that must be sacrificed in order to power the magic. The former

represents the mental energy that is used up in channeling the cancerous energies of the Mythos;

the latter represents the psychic damage that this causes.

In some spell descriptions, the caster is required to make a permanent sacrifice of one or more

points of POW. These are usually the most powerful forms of magic.

In order to cast a spell, an individual must first already know the spell (see the preceding section for

the mechanics of learning spells from Mythos Tomes). With this pre‐requisite, all that is required is

for the caster to make the appropriate sacrifice of points. The spell description will describe the

likelihood of this sacrifice effecting a supernatural effect – this is usually some form of percentile die

roll. Note that if the spell caster does not have sufficient points to sacrifice, his or her efforts can

never succeed. Also, if the appropriate points are sacrificed and the roll subsequently failed, the

points are still lost (for no result).

The sole exception to the requirement to sacrifice points is for spellcasters whose SAN is already

zero – those NPCs do not need to sacrifice Sanity to activate magic. Their minds are already lost to

the powers of the Cthulhu Mythos, and cannot get any more broken by further exposure.

Regaining Sacrificed Points As described in MAGIC POINTS AND MENTAL EXHAUSTION on page 28, an Investigator’s full

complement of Magic Points gets refreshed every 24 hours as long as he or she has been able a level

of rest, up to current POW. It is often convenient to break this down into an assumed gain of ¼ of

the Investigator’s POW each six hours of downtime.

Sacrificed points of SAN do not refresh by themselves, although gains of SAN caused by other events

can replace these (see RECOVERING SANITY on page 54 for a description of regaining SAN). Note

that regardless of circumstances, an Investigators SAN can never be higher than 99‐Cthulhu Mythos.

Sacrificed points of permanent POW never refresh by normal means. Conceivably there might be

ways and means of getting back such major expenditures; these are for you as Keeper to invent.

Typically, this would represent a major undertaking – perhaps even an entire new.

EXAMPLE: During Professor Walter Mason’s seven months spent researching the Latin

Necronomicon, he noted several passages that seem to describe rituals of power that adepts can

employ to channel dark powers. One in particular piques the professor’s curiosity – a page‐long

incantation headed “For to bring down the winged servitors to undertake thy bidding.” Deciding this

is likely some kind of spell, Walter makes an attempt to learn it. Sam, the Keeper, looks up the

statistics for the Olaus Wormius tome and notes that it has a ×5 spell multiplier. Walter will need to

spend some time trying to decipher the spell – Vanessa rolls 2D6 and gets a 4, indicating he will need

to invest 4 weeks effort. At the end of this time Vanessa rolls a 1D100 and compares it against

Walter’s INT × 5. Walter’s INT is 16, so as long as the roll is 80 or less, the attempt to learn the spell


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will succeed. Vanessa rolls 27 so Walter learns the “Winged Servitor” spell (actually a ritual to

summon a hideous monstrosity known as a Night‐gaunt”). What the text does not clearly mention is

that while this spell can bring such a beast to the caster’s location it does not, by itself, grant control

over the monstrosity. That is a different spell, which is also buried away in a separate part of the

Necronomicon. If Walter continues to pore over the tome’s detailed rituals he might come to this

realization; if he attempts to cast the summoning spell straight away he may also learn this fact,

albeit in a potentially‐deadly way.

Powers of the Cthulhu Mythos The fiction of H.P. Lovecraft is filled with obscure and half‐hinted references to vastly powerful

forces of the Cthulhu Mythos – a loose collection of unfathomable horrors, any of which could

overwhelm our planet in a moment if they had the desire. Fortunately for humanity, these immense

and mighty Mythos Powers typically have no reason to take interest in our planet, and in particular

the activities of the human race. For, despite our own obsession with the technology and social

structures we have built for ourselves, these mean virtually nothing on a cosmic scale. The Powers of

the Cthulhu Mythos – with a few exceptions – no more worry about humanity than we are

concerned with the day‐to‐day life of ants beneath our feet.

Part of the reason H.P. Lovecraft’s powerful and god‐like forces are so frightening is because the

stories really only hint at them, providing outré and hard‐to‐pronounce names to concepts that are

truthfully far beyond our ability to understand. The most powerful “gods” of the Mythos turn up as

names in blasphemous tomes, corrupting mental influences, and subjects of worship for degenerate

cults, but very rarely do they manifest in physical form. On the few occasions where these

formidable powers are experienced by humans – such as the memorable encounter between

Cthulhu and the crew of the Alert (in Lovecraft’s “The Call of Cthulhu”) – it is an impossibly

dangerous and sanity‐blasting event.

Encountering a Mythos Power As an Open Cthulhu Keeper, you may wish to introduce these most powerful forces of the Cthulhu

Mythos into your game scenarios. In order to evoke a similar tone to that of Lovecraft’s fiction, you

should always keep the following guidelines in mind:

Hint rather than show outright: Through implication or subtle half‐glimpses of horrific

manifestations, it’s possible to communicate the vast power and utter alienness of Mythos

Powers without ever having to nail down a concrete “appearance” for them. A literal

description is never going to be as frightening as what each player mentally fills into the gap

left by a sketchy half‐hinted portrayal. This is one of the techniques that Lovecraft uses most

effectively to create a vague mythology whose individual entities would probably seem more

ridiculous than scary if depicted in a detailed way.

Mythos Powers shouldn’t be “boss monsters”: Gamers love to have grand adversaries to

fight off at the conclusion of their epic campaigns – for the most part explicit encounters

with Mythos Powers don’t serve this need. This is because Powers embody such vast and

horrific energies that a physical confrontation is much more likely to result in the entire

Investigator party being wiped out than in a dramatically‐satisfying epic battle. Using the

threat of a Mythos Power manifesting is usually more dramatic; as is providing a non‐

combat encounter to engineer a “close call” between the Investigators and the terrifying

hidden forces of the Mythos.


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Focus attention on human worshippers: Some Mythos Powers are known to have “cults” of

followers; others are known to be “worshipped” by lone‐wolf types who yearn for forbidden

and secret power. Pitting the Investigators against these types of adversaries is often a

convenient way of providing physical challenges where the odds of success are close to

even. Interacting with the human agents of Mythos Powers – who may be somehow guided

by the Power or may just think they are doing their “gods” bidding – is a good way to hint at

the true nature of the entity, through the lens of the cult’s belief system.

Mental contact is dangerous; physical contact is virtually guaranteed deadly: Mythos

Powers are ancient forms of existence that are totally unlike anything human beings have

ever experienced. They are intelligent, but in a way that makes no sense to us. Having your

mind connected to such a being is like sticking a fork into an electric socket – a massive

shock to the system which might leave you a broken wreck. This is nothing compared to the

experience of physically encountering such a being, however. Few survive even a short

period in the presence of matter inherently corrosive to our concept of universal existence

and laws of physics.

Powers are never consistent; never predictable: Some individual worshippers of Mythos

Powers and occult scholars who try to comprehend the Cthulhu Mythos, like to invent

systems for categorizing Mythos Powers. Such taxonomies are inherently imperfect, based

as they are on the extrapolations made by broken minds from scarcely‐understood facts.

You should freely adopt these labels if needed, calling this or that Power a member of the

group of “Great Old Ones” or “Elder Beings” or “Outer Gods”. Equally, you should feel free

to contradict any previous statements or information about the Powers or their

categorization. Human wisdom will never understand the Cthulhu Mythos, hence anything

that men and women claim to “know” might just as easily be an imperfect or incorrect

assumption. Or simply a lie. This gives you, as Keeper, infinite freedom to deliberately

contradict previous “facts” about a Mythos Power or upend anything the players believe

they “know” about the Cthulhu Mythos. Indeed, by doing so you can reinforce the basic

principle that the mythos is fundamentally unknowable.

For more excellent advice and guidance on ways to present the forces of the Cthulhu Mythos in a

manner that is suitably redolent in Lovecraft’s distinctive style, Keepers are strongly recommended

to read Graham Walmsley’s book “Stealing Cthulhu.”

Mental Contact with the Infinitely Alien Investigators may come into mental contact with a Mythos Power in many different ways. Some

Powers (most famously Cthulhu) are known from time‐to‐time to afflict the dreams of sensitive

persons, even across the other side of the world. Alternatively, an Investigator may deliberately seek

out such communion via a ritual, or by making use of a terrible Mythos artifact.

The experience of mental contact with a vast and impossibly inhuman intelligence should not be

brushed over with a few die rolls. It is, after all, a potentially mind‐shattering and life‐changing event

for the Investigator(s) so connected. As Keeper, you should aim to convey something of the

confusion and nightmarish impressions that come as side‐effects of contacting something utterly

unfamiliar. Above all the background noise of odd and alarming impressions, the alien Will of the

Mythos Power should be a terrifying and sonorous palpitation. A sensation like the laws of reality

being violated and corrupted by an impossibly potent mental presence. Each such encounter should

be a unique, but always utterly disconcerting, experience.


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In terms of game mechanics, the experience of mental communion with a Mythos Power is largely a

matter for a SAN roll (see the individual Power descriptions below). The SAN roll will determine the

degree to which the Investigator’s mind is destroyed by the impossible sensations to which it is

exposed. Beyond this, however, you should resolve the encounter in a narrative way – does the

experience teach the Investigator valuable information relevant to the scenario? Does the channel

to the Mythos Power permit the Investigator to seek answers to specific questions? If so, how would

the inhuman intelligence choose to fashion any responses? Answers to all such questions should be

driven by the needs of the story, making the mental encounter a pivotal, if deadly, moment which

drives the scenario forwards in a dramatic way.

Coming Face‐to‐Face with a Living God Investigators who have the misfortune of coming into physical contact with a manifestation (or

avatar) of a Mythos Power will face nigh‐on‐impossible peril. Very few people survive such an

encounter intact; of those few, most are driven insane by the experience. The experience of meeting

a “living god” should be a terrifying and debilitating jolt which will forever scar all who were present.

The physical forms of the Mythos Powers are both hideous (causing grave SAN loss) and composed

of modes of physical reality which are thoroughly unfamiliar to our experience. Because of this, even

being in the proximity of such a physical manifestation can be deadly.

The vastly powerful and alien nature of these physical forms means that it is seldom sensible to run

such encounters using the traditional combat rules. While some Lovecraftian roleplaying games

provide combat statistics for Cthulhu and other god‐like beings, Open Cthulhu does not. Instead the

Keeper is encouraged to play out such an encounter in narrative terms. If the Mythos Power wants

to swat a particular Investigator or NPC, chances are that its attack will always succeed and likely

destroy the person utterly. Similarly, even powerful human weapons do nothing more than pierce

the alien flesh of the Power’s physical “puppet” body. Given such an imbalance of power, it’s

preferable to treat the encounter in terms of driving the story forwards in a particular direction. If

you want to demonstrate the sheer power of the Mythos, have the Power horrifically crush a few

NPCs without raising a sweat. Or allow the Investigators to detonate their most potent weapon

successfully but inflict no visible effect on the Power.

Under no circumstances will direct physical combat with a Mythos Power end in any other way than

the utter destruction of all human combatants. Given this axion, you as Keeper should only ever

instigate such an encounter for one of two reasons: either the players have massively failed in some

way, or there is an alternate non‐combat way in which the Mythos manifestation can be banished or

redirected to achieve victory. In the latter case, the job of constructing a dramatically‐satisfying

means of resolving the encounter is entirely up to you. While the resolution might involve

Investigator dice rolling, it should be led ultimately by the needs of the story. Don’t be afraid to

punish abject failure (or those who insist on going toe‐to‐toe in a fist fight with Nyarlathotep or

punching Cthulhu in the face). But equally, seek out ways to reward clever suggestions by players –

indeed, if a player invents some novel way of resolving the situation that seems dramatically

exciting, consider adapting your original plans to incorporate the player’s suggestion.

To assist with the presentation of terrifying physical encounters with a Mythos Power, the

descriptions of Powers include five statistics:

SAN loss to make mental contact: Humans may come into mental contact with Mythos

Powers in several ways, most notably through the use of rituals or other magic. In each case,

successful communion is damaging to the sanity of all involved.


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Physical SIZ: While the physical form adopted by a Mythos Power can vary at the whim of

the entity, it is useful to have a rough idea of how massive or modest it usually appears.

Some Mythos Powers are vast – larger than a battleship, or half‐a‐mile across, while others

are approximately human size. These rough guidelines can help to describe the physical

form in a way which conveys the magnitude of the being (although don’t get hung up on

precise measurements – in the heat of an encounter, nobody will have the presence of mind

to accurately gauge comparative size).

POW: This statistic may be helpful in determining the potency of spell‐like attacks launched

by the Power. It is also important for attempts to “dismiss” a physical manifestation of the

Power (see DISMISSING A MYTHOS POWER, page 123).

SAN loss to behold the physical manifestation: Most physical forms adopted by Mythos

Powers are (to human eyes at least) among the most hideous and disturbing things

imaginable. Encountering such manifestations is inherently shattering to Investigator SAN,

quite possibly driving witnesses permanently insane in an instant. As Keeper, you have the

freedom to either impose this devastating SAN loss as a single terrible moment of horror or

divide the points‐loss up and apply it piecemeal at key moments throughout the encounter.

This decision can drastically alter the flow of the encounter, since Investigators who suffer

enormous SAN losses are likely to be (at best) quickly incapacitated, or (at worst) may even

turn on their colleagues. While dramatic, you should also consider whether the needs of the

story may better be served by delaying some of the SAN loss until later, when the

Investigator reflects on what has occurred.

Physical Lethality of attacks: If you decide to run an encounter between Investigators and a

Mythos Power as a physical combat, you will need to decide for yourself the likelihood of the

Power’s attacks afflicting one or more human combatants. This should be decided based on

the specific situation and any protective measures the Investigators have thought to apply.

Consider all these factors and make a judgement call. The baseline should be that, in the

absence of special protections or favorable circumstances, the physical form of a Mythos

Power has a 100% chance of massively damaging one or more individuals within its reach.

The types of damage delivered will vary according to the physical form but will always have a

Lethality Rating of some type (see LETHALITY RATING on page 37). The description blocks

for each Mythos Power, below, offer some suggestions about the style of physical attack,

the number of individual targets that may be engaged each round, and the Lethality Rating

of each attack. Note that the enormous size of some manifestations means that their deadly

attacks are not limited to individual targets but affect all beings within a nominated radius.

Mythos Powers from Fiction Included below are a selection of the Mythos Powers which are referenced in Lovecraft’s fiction and

stories created by his successors. It is not intended to be an exhaustive “mythology” of gods but a

source of ideas for malign influences to infuse your game. In all cases we suggest going back and

reading the original stories which introduce these entities (referenced in the listings), to fully

appreciate the original author’s concept.


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Azathoth Azathoth sits at the center of the universe where multiple dimensions come together. It is a

shapeless mass of pure chaos and is surrounded by a court of weird servants. Some philosophers

posit that Azathoth created the universe. Cults dedicated to the being are rare.

[Reference: “The Dream‐Quest of Unknown Kadath” by H.P. Lovecraft (1927)]

Sanity Loss (Mental Contact): 1D6/1D20 Physical SIZ: varies, expanding exponentially over time (first round 50 yards across, second round 100 yards, third round 200 yards, etc.) POW: 100 Sanity Loss (Physical Manifestation): 1D10/1D100 Physical Lethality: 60 with Kill Radius 3yds first round doubling each successive round (corrosive

touch; up to 6 times per round)

Cthulhu An ancient alien being who descended upon the Earth millions of years ago in the accompaniment of

his multitudinous STAR‐SPAWN (see page 99), Cthulhu is huge and roughly humanoid with bat‐like

wings and a tentacled, octopoid head. Cthulhu cults are incredibly old and varied and may be

encountered anywhere in the world. Cthulhu’s followers believe that he lies in the sunken city of

R'lyeh, not dead but dreaming, and that he will awaken to rule the world once again. Cthulhu speaks

to his followers, and sometimes to the uninitiated, through dreams.

[Reference: “The Call of Cthulhu” by H.P. Lovecraft (1926)]

Sanity Loss (Mental Contact): 1D4/1D10 Physical SIZ: ~210 (roughly the size of a battleship) POW: 42 Sanity Loss (Physical Manifestation): 1D10/1D100 Physical Lethality: 66 with Kill Radius 2yds (flabby claws or face tentacles; up to 4 times per round)

Dagon Sometimes called Father Dagon, the creature is the “god” of the DEEP ONES (see page 81) and

himself may serve Cthulhu in some manner. He appears to be a massively grown, fish‐like Deep One,

and is likely simply the oldest surviving of that aquatic race. Dagon makes his home deep in the sea

but might be summoned with the proper rituals. Human cults dedicated to Dagon, such as the

Esoteric Order of Dagon, are sometimes uncovered in coastal towns where humans make unnatural

pacts with Deep Ones.

[Reference: “Dagon” by H.P. Lovecraft (1917)]

Sanity Loss (Mental Contact): 1/1D4 Physical SIZ: ~60 (roughly the size of a bi‐plane) POW: 30 Sanity Loss (Physical Manifestation): 1/1D10 Physical Lethality: 21 with Kill Radius 2yds (monstrous claws; up to twice per round)

Nyarlathotep Nyarlathotep has been worshipped across the globe in hundreds of guises and his true form is only

rumored. He was venerated among the antediluvian Stygians, and among the Egyptians he was

known as the Black Pharaoh. European witch cults refer to him as the Dark Man and buy his secrets

at a steep price. Similar beliefs are found in Africa, Asia, and South America. Nyarlathotep takes


Page 78

great pleasure in dealing with humanity and causing the tide of chaos to rise, and his cults are

frighteningly common. The Shining Trapezohedron (see MYTHOS ARTIFACTS, page 131) is an

important artifact among his followers.

[Reference: “Nyarlathotep” (1920) and “The Dream‐Quest of Unknown Kadath” (1927), both by H.P.

Lovecraft

Sanity Loss (Mental Contact): 1D3/1D6 Physical SIZ: varies by form; from man‐sized through to ~90 (roughly the size of an armored tank) POW: 100 Sanity Loss (Physical Manifestation): varies based on form, from 0/1D2 for human‐like forms to 1D10/1D100 for especially monstrous forms Physical Lethality: varies based on form with human forms typically using weapons; monstrous

forms have lethality 60 (by form; once per round)

Shub‐Niggurath In her natural form, Shub Niggurath is a black, cloud‐like entity. Usually depicted with female

characteristics, Shub Niggurath is a fertility deity who bestows numerous children upon her

followers, for a price. She is called the Black Goat of the Woods and is said to have a thousand

young.

Sanity Loss (Mental Contact): 1D6/1D20 Physical SIZ: ~120 (roughly the size of a jumbo jet) POW: 70 Sanity Loss (Physical Manifestation): 1D10/1D100 Physical Lethality: 33 with Kill Radius 2yds (seize, bite, or trample; once per round)

Wendigo Known by various names among the people of the northern climes, the Wendigo is a terrible

creature associated with winds. Wendigo appears as a shapeless, translucent mass that constantly

expels vigorous winds, but also appears as a roughly human, large‐footed mammalian who traverses

the wilderness and the winds with equal ease.

Sanity Loss (Mental Contact): 1D3/1D6 Physical SIZ: ~100 (roughly the size of a zeppelin) POW: 35 Sanity Loss (Physical Manifestation): 1D10/1D100 Physical Lethality: 24 with Kill Radius 10yds (wind blast; once per round)

The Yellow King Known as the “Faceless God,” for the mask he wears and as the “Unnameable,” due to the power of

his true name, the Yellow King reigns in Carcosa on the shore of the Lake of Hali, where the giant

orange sun, Aldebaran, and nameless black stars hang in the sky. He is the patron of corruption,

decadence, and madness, and his cultists believe that they will be transported to (or reborn in)

Carcosa to live eternally in the king’s splendor. The play The King in Yellow is said to reveal secrets

about the Yellow King and his worship.

[Reference: “The King in Yellow” by Robert W. Chambers (1895)]


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Sanity Loss (Mental Contact): 1D3/1D6 Physical SIZ: ~14 (roughly 6 feet tall) POW: 35 Sanity Loss (Physical Manifestation): 1D3/1D10 Physical Lethality: 15 (razor sharp tatters plus mental blast; once per round)

Yog‐Sothoth A transdimensional being that appears as a disordered mass of luminescent spheres, Yog‐Sothoth

has power over time and space and may exist outside both. In Mythos lore, it is said to be “the gate,

the key, and the Guardian of the gate”, but what this might mean is unknown to the uninitiated.

Yog‐Sothoth is worshipped by the MI‐GO (see page 92) and also converses with sorcerers who seek

its patronage.

Sanity Loss (Mental Contact): 1D6/1D20 Physical SIZ: inconstant; sometimes seems to be a collection of spheres 100 yards across while the next moment may seem half a mile wide POW: 100 Sanity Loss (Physical Manifestation): 1D10/1D100 Physical Lethality: 98 with Kill Radius 5yds (contact with unearthly matter; once per round)

Creatures of the Cthulhu Mythos Included below are game statistics for some of the Cthulhu Mythos creatures mentioned or

encountered in the stories of H.P. Lovecraft and others. This is not intended to be an exhaustive

catalogue of horrors but a helpful bestiary to populate your Open Cthulhu scenarios with a diversity

of creatures. Other previous Lovecraftian games have included detailed monster catalogues, some of

which are statistically‐compatible with Open Cthulhu; accessing these resources can add extra

choices for the Keeper.

Colour Out Of Space “It was just a colour out of space – a frightful messenger from unformed realms of infinity beyond all

Nature as we know it …”

– H. P. Lovecraft, “The Colour Out of Space” (1927)

Descending from the unknown reaches of the cosmos, Colours Out of Space seem to be a sentient

form of radiation. They lack any distinguishable form and appear in darkness as a vague glow of an

unidentifiable color from outside the normal spectrum. Their spores are born through space deep

inside asteroids and are released when they crash into a planet’s surface. The spore seeks a wet,

dark den in which to reside, such as a well or lakeside cave. From there, it infects the immediate area

with an unusual “sickness”, drawing energy away from living things. Plant life is first affected, but as

the Colour gains power, it preys upon small animals and larger creatures. Its weird influence causes

lifeforms to be mutated, sometimes doubling in size, before undergoing a miserable agony and

crumbling to dust. By this time, the area exhibits serious decay and lifelessness. Once it has gained

sufficient energy, the Colour shoots off into space to infect other worlds.


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Characteristic Dice Average Random 1 Random 2

STR 1D6 per 10 points of POW or part thereof

7 4 11

CON N/A N/A N/A N/A

SIZ Same as POW 10‐11 4 14

INT 4D6 14 12 17

POW 3D6* 10‐11 4 14

DEX 2D6+12 19 14 22

HP N/A N/A N/A N/A

DB derived 0 ‐1D6 +1D4

* The Colour’s POW (and hence its STR and SIZ) increases as it feeds

Attacks

# Attacks per Round: 1

Feed 85% damage 1D6 + Drain Characteristics (see below)

Mental Drain (see below)

Grasp 85% as per a PIN action (see page 32; portion of Colour takes physical form)

Drain Characteristics: When a Colour chooses to feed on a human, compare the creature’s POW with the victim’s POW. For every 10 full points which the Colour’s stat exceeds the victims, the latter will lose 1 permanent point from each of STR, CON, POW, DEX, and CHA. This attack also costs 1D6 Hit Points. Each point of POW drained is added to the Colour’s POW.

Mental Drain: If the Colour wishes to mentally weaken those in proximity to its location, it can compel an individual to perform an opposed test which matches the Colour’s POW versus the victim’s INT. If the victim is defeated in this test, he or she immediately loses 1D6 Magic Points + 1D6 Sanity Points. People who have had their will broken by this power often become reluctant to leave the area affected by the Colour.

Defenses

Armor: None, but Colours are not affected by any physical attacks. Magical attacks affect Colours normally.

vs Lethal Damage: IMMUNE – not affected by physical attacks yielding Lethal Damage.

Special

Signs of Affliction: Colours affect the very landscape they haunt, causing the soil, trees, and everything else to glow slightly with an alien tint. When inspecting a tainted area, these signs can be detected with an INT × 4 roll; this will also detect the unexpected smell of ozone.

Physical Disintegration: If a Colour wishes to burn a hole through any substance (no matter how strong), it can concentrate all its energies into a single beam of light. The amount of matter disintegrated in a given time depends on the density of the material. While the resulting hole appears to have marks around the edges suggestive of melting, this use of power actually generates no heat, just light.

Movement: Colours Out Of Space can move 15 meters/yards in a combat round while rolling along

the ground; 25 meters/yards while flying.

Sanity Loss: Seeing a Colour Out Of Space causes a loss of 0/1D4 Sanity Points. Witnessing the

effects of a Colour on a human victim causes a loss of 1/1D8.


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Deep Ones “They were mostly shiny and slippery, but the ridges of their backs were scaly. Their forms vaguely

suggested the anthropoid, while their heads were the heads of fish, with prodigious bulging eyes that

never closed.”

– H. P. Lovecraft, “The Shadow Over Innsmouth” (1931)

A fish‐like humanoid race unimaginably older than humanity, Deep Ones live in undersea cities and

worship Dagon and Cthulhu. They have scaled, rubbery skin, webbed digits, and round, staring eyes.

Deep Ones are known to cavort with humans in seaside towns, trading their favors and alien

goldwork for service and worship of Dagon. Deep Ones can mate with humans, and the half‐breed

offspring are doomed to transform into sea‐folk over time, eventually becoming entirely Deep One.

The creatures are immortal, dying only to violent causes, and continue to grow throughout their

lives. Deep Ones attack with savage claws. Though they can breathe underwater indefinitely, they

can also survive out of water for several hours.


STR 4D6 14 6 19

CON 3D6 10‐11 8 14

SIZ 3D6+6 16‐17 16 20

INT 2D6+6 13 15 11

POW 3D6 10‐11 14 13

DEX 3D6 10‐11 12 13

HP derived 13‐14 12 17

DB derived +1D4 0 +1D6

Attacks

# Attacks per Round: 1. Deep One typically use human weapons, although they can use their claws.

Claws 45%, damage 1D6 + damage bonus

Weapon 45%, damage by weapon type; melee weapons will add damage bonus

Defenses

Armor: 1 point of thick scales and flabby hide

vs Lethal Damage: NORMAL – affected by Lethal Damage the same way humans are affected.

Special

Spells: Especially powerful Deep Ones (POW 14+) may know a few spells.

Breathe Underwater: All Deep Ones can naturally breathe underwater.

Movement: Deep Ones can move 10 meters/yards in a combat round on the ground; 13

meters/yards while swimming.

Sanity Loss: Seeing one of the Deep Ones causes a loss of 0/1D6 Sanity Points.


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Dimensional Guardian The Dimensional Guardian is a humanoid entity with shaggy brown fur, long arms, vicious claws and

a malicious grin. The Guardian can cross the barrier between different dimensions, though it is

unclear how and why it does this. While Dimensional Guardians have a brutish intellect, their

knowledge of the planes and their relations is unmatched. Guardians do not need to eat and can

thus survive in places too alien to offer any food or water. This makes them ideal servitors for those

who wish to protect an isolated location for long periods of time.


STR 2D6+12 19 18 24

CON 3D6+6 16‐17 17 20

SIZ 2D6+12 19 20 22

INT 2D6 7 6 8

POW 3D6 10‐11 14 15

DEX 3D6 10‐11 12 17

HP derived 18 19 21

DB derived +1D6 +1D6 +2D6

Attacks

# Attacks per Round: either 2 claw attacks or a single grab attack.

Claw 30% damage 1D8 + damage bonus

Grasp 45% as per the Grapple skill (treat as a PIN action, see page 32)

Defenses

Armor: 3 points of leathery hide


Special

Trans‐dimensional Travel: Dimensional Guardians have an innate ability to travel between different dimensions. Initiating a transition from our dimension to another takes a full (uninterrupted) round and costs the Dimensional Guardian 4 Magic Points. If the Guardian is holding anything or anyone (e.g., someone held by its Grapple), they too make the journey.

Movement: Dimensional Guardians can move 9 meters/yards in a combat round.

Sanity Loss: Seeing a Dimensional Guardian causes a loss of 0/1D10 Sanity Points.

Elder Things “Complete specimens have such uncanny resemblance to certain creatures of primal myth that

suggestion of ancient existence outside Antarctic becomes inevitable. Dyer and Pabodie have read

Necronomicon… and will understand when I speak of Elder Things supposed to have created all

earth‐life as jest or mistake.”

– H. P. Lovecraft, At the Mountains of Madness (1931)

One of the first advanced races on Earth, Elder Things have a singular appearance. Somewhat barrel‐

shaped, they stand up to 10 feet in height and have membranous wings, gills, many‐tentacled arms,

and yellow, five‐pointed starfish‐shaped heads. They walk by means of a starfish‐like “foot” and are

equally at home underwater, on land, or flying in the air, though the Elder Things of Earth lost the

ability to fly eons ago. The Elder Things once had an advanced scientific and artistic culture whose

remnants might still be uncovered on Earth.


Page 83


STR 4D6+24 38 36 41

CON 3D6+12 22‐23 23 25

SIZ 8D6 28 29 43

INT 1D6+12 15‐16 14 15

POW 3D6 10‐11 9 13

DEX 3D6+6 16‐17 17 23



Attacks

# Attacks per Round: can attack with all 5 of its tentacles, but no more than 3 against a single foe.

Tentacle 40%, damage = (half damage bonus) + Constrict/Crush (see below)

Constrict/Crush: If one of the Elder Thing’s tentacles successfully strikes an enemy it will wrap around it and continue to crush it in later rounds. Unless freed by external means, the victim will continue to suffer Hit Point damage equal to half the Elder Thing’s damage bonus in each succeeding round.

Defenses

Armor: 7 points of rugose skin.

vs Lethal Damage: HIGHLY RESILIENT – a successful Lethality roll does not kill an Elder Thing but inflicts normal Hit Point damage equal to the Lethality Rating, less the normal armor rating (minimum 1 HP).

Special

Spells: Each Elder Thing has a percentage chance of knowing a few spells equal to its INT × 3.

Movement: Elder Things can move 10 meters/yards in a combat round on the ground; 13

meters/yards while flying.

Sanity Loss: Seeing an Elder Thing causes a loss of 0/1D6 Sanity Points.

Fire Devil Fire Devils are spherical creatures that consist of living flame. They are said to originate from a

faraway star. Fire Devils are sentient. If summoned, they appear as flaming meteors in the sky. A

swarm of fire devils is a beautiful as it is destructive.


STR N/A N/A N/A N/A

CON 2D6 7 7 10

SIZ 1 1 1 1

INT 3D6 10‐11 7 12

POW 2D6+6 13 16 18

DEX 3D6+6 16‐17 13 18

HP = CON 7 7 10

DB N/A N/A N/A N/A


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Attacks


Touch 85%, damage Heat Shock (see below) + optional Magic Point Drain (see below)

Heat Shock: Touching a Fire Devil can cause a victim up to 2D6 Hit Points of damage. Roll 2D6 to determine potential damage, then make an opposed test comparing the victim’s CON with this damage (i.e., opposing victim’s CON vs damage total). If the victim loses the opposed test, he or she takes the full value of the rolled damage. If the victim wins the test, only half of the damage (round up) is inflicted.

Magic Point Drain: When touching a victim, the Fire Devil can (if it so chooses) also attempt to drain Magic Points. This special effect is resolved by making an opposed test comparing the Devil’s current MP total versus the victim’s MP total. If the Devil wins the opposed test, the victim loses 1D10 MP, transferring these points to the Devil. If the victim wins the test, the Fire Devil loses 1MP.

Defenses

Armor: Intangible and immune to all physical damage; takes normal damage from Magic.

vs Lethal Damage: see above.

Special

Burn on Touch: Flammable objects that touches the Fire Devil instantly catch alight.

Movement: Fire Devils can move 13 meters/yards in a combat round while flying.

Sanity Loss: Seeing a Fire Devil causes no loss of Sanity Points.

Flying Polyps “... a horrible elder race of half‐polypous, utterly alien entities which had come through space from

immeasurably distant universes and had dominated the earth … about six hundred million years

ago.”

– H. P. Lovecraft, “The Shadow Out of Time” (1935)

Flying Polyps are entirely alien to Earth. They have a composition that is only partly material that

allows them some amount of plasticity. They speak in odd whistles, fly via a form of levitation, and

lack eyesight, instead relying on other senses to perceive the world. They stand some 10 to 15 feet in

height and their form is generally cylindrical, if amorphous, with insectoid legs ending in five toe‐like

stalks.

At one time, the polyps created great, basalt, tower‐cities, but approximately 150 million years ago,

the GREAT RACE (see page 87) imprisoned the entire race of Flying Polyps in subterranean vaults

and caverns. Few of the creatures remain in the modern world.


STR 4D6+36 50 52 55

CON 2D6+18 25 23 23

SIZ 4D6+36 50 42 53

INT 4D6 14 7 19

POW 3D6+6 16‐17 11 16

DEX 2D6+6 13 9 13

HP derived 38 33 38



Page 85

Attacks

# Attacks per Round: Can attack each round with 2D6 Tentacles (re‐roll each round) or use the Windblast attack against one target.

Tentacle of Wind 85%, damage 1D10 (ignores armor)

Windblast, damage Lethality 15%, to a 10‐yard radius (if target within 20yds), For distant targets, reduce Lethality 3% per multiple of 20 yards distant (e.g., 41 yards; 9% Lethal) + Blowback

Fixing, (see below)

Blowback: Targets affected by a Windblast attack are blown backwards a number of yards equal to the Hit Point damage they sustained. If they died from Lethal Damage they are blown backwards 5D6 yards. Fixing: The whistling wind continuously emanating from a Flying Polyp can be shaped in such a way that it creates a sucking vortex which can cause one or more targets to become stuck, unable to move away from the creature. The Polyp can direct this attack against multiple targets in a 30‐yard radius of one another, as long as the group is less than 1,000 yards of the Polyp. Each person targeted in this manner must make an opposed test against the Polyp to be allowed to move that round. If the target is within 500 yards the opposed test pits the target’s STR against the Polyp’s POW. If the target is 500‐1,000 yards distant, the test compares target’s STR against HALF the Polyp’s POW. If the power has been directed against more than one target, all victims’ opposed test rolls have a +5 percentile chance for each target beyond the first. Note that while employing this attack the Polyp can still move normally; hence it is frequently employed as a means of catching up with targets who are fleeing.

Defenses

Armor: none, but only takes damage from electricity, magic, weapons with a Lethality of 15%+ and explosions with a Lethality of 15%+.

vs Lethal Damage: PARTIALLY NON‐CORPOREAL – attacks with a Lethality Rating < 15% cannot damage a Polyp at all. Attacks with a higher rating do not destroy the Polyp but may yield Hit Point damage if they strike at a moment when the Polyp is corporeal. If the die roll made for the Lethal Damage was an odd number, the Polyp was insubstantial at the crucial moment and the attack passes through it; if the die roll was an even number the Polyp suffers Hit Point damage equal to the Lethality Rating.

Special

Spells: More intelligent Polyps may know a moderate selection of spells; roll 1D20 – if the number is less than the Polyp’s INT, this individual knows some spells of the Keeper’s choice.

Invisible: Spending 1 MP per round will allow a Polyp to become fully invisible, although it may still be approximately located by the peculiar whistling emanating from it. Invisible Polyps do not attack with Tentacles of Wind but will readily employ other types of attack. Windstorm: A Flying Polyp can whip up a terrifying windstorm and can join with others of its species to collectively brew up an even more damaging maelstrom. The storm that results from this power has a windspeed of 0.5 miles‐per‐hour for each point of POW possessed by the Polyp (or group of Polyps). This is a localized storm centered around the Polyp(s) and rapidly drops off in ferocity for each 200 yards one travels away from the epicenter. If a human is caught within a powerful storm (60+ miles per hour), he or she may suffer Hit Point damage. This is resolved by the target attempting a POW‐related roll to avoid damage. If the windspeed is 60mph the roll is POW × 5 to avoid damage; for each 15mph above that an additional POW roll is required with a multiplier one less than the previous roll (to a minimum of POW × 1). For each roll that is failed, the target takes 1D4 Hit Points of damage.

Movement: Flying Polyps can move 10 meters/yards in a combat round on the ground; 15


Sanity Loss: Seeing a Flying Polyp causes a loss of 1D3/1D20 Sanity Points.


Page 86

Ghasts “ … those repulsive beings which die in the light, and which live in the vaults of Zin and leap on long

hind legs like kangaroos.”

– H. P. Lovecraft, The Dream‐Quest of Unknown Kadath (1927)

Strange creatures native to the Dreamlands, ghasts are carnivorous pack hunters that prey on

ghouls, gugs, and other creatures. Ghasts are about the size of a mule, but stand on kangaroo‐like

hind legs, have scabrous skin, and a vaguely human face that is missing both nose and forehead.

They attack by biting and kicking with their sharp hooves. Ghasts have a sunlight sensitivity, which

causes them to sicken when exposed to direct sunlight (and eventually die after prolonged

exposure). They can tolerate artificial light and the dim light of dusk or dawn.


STR 3D6+12 22‐23 23 25

CON 4D6 14 12 17

SIZ 4D6+12 26 32 34

INT 1D6 3‐4 4 5

POW 3D6 10‐11 7 15

DEX 2D6+6 13 13 15

HP derived 20 22 26


Attacks


Bite 40%, damage 1D10

Kick 25%, damage 1D6 + damage bonus

Defenses

Armor: 3 points of thick skin.

vs Lethal Damage: RESILIENT – a successful Lethality roll does not kill a Ghast but inflicts normal Hit Point damage. Take the percentile roll made for Lethal Damage, treat each of the dice as a D10 and add them together. This is the amount of Hit Point damage inflicted, less the normal armor rating (minimum 1 HP).

Special

Notable Skills: Sneak 70%

Movement: Ghasts can move 13 meters/yards in a combat round.

Sanity Loss: Seeing a Ghast causes a loss of 0/1D8 Sanity Points.

Ghouls “It was a colossal and nameless blasphemy with glaring red eyes, and it held in its bony claws a thing

that had been a man, gnawing at the head as a child nibbles at a stick of candy.”

– H. P. Lovecraft, “Pickman’s Model” (1926)

Ghouls are carnivorous humanoids that feed on cadavers and dwell predominantly in the

Dreamlands. Ghouls regularly pass into the physical realm, sometimes keeping underground

communities in remote caverns and unused sewer systems, slipping into graveyards and

mausoleums in search of their grisly feasts. Ghouls are humanoid, with short, canine snouts, hoofed

feet, and rubbery skin. They smell of mildew and mold.


Page 87


STR 3D6+6 16‐17 19 20

CON 2D6+6 13 10 13

SIZ 2D6+6 13 11 17

INT 2D6+6 13 10 16

POW 2D6+6 13 13 16

DEX 2D6+6 13 11 17

HP derived 13 11 15


Attacks

# Attacks per Round: up to 3 (two claws and a bite).


Bite 30%, damage 1D6 + Worry (see below)

Worry: If a Ghoul succeeds in biting a victim it clamps its jaws and holds on. For each successive round, the victim takes 1D4 Hit Points damage, until the creature is dislodged (e.g., with a Grapple move).

Defenses

Armor: None

vs Lethal Damage: RESILIENT – a successful Lethality roll does not kill a Ghoul but inflicts normal Hit Point damage. Take the percentile roll made for Lethal Damage, treat each of the dice as a D10 and add them together. This is the amount of Hit Point damage inflicted.

Special

Notable Skills: Burrow 75%, Climb 85%, Hide 60%, Jump 75%, Listen 70%, Sense of Smell 65%, Sneak 80%, Spot Hidden 50%.

Spells: Has a small chance of knowing one or two spells if INT is especially high.

Movement: Ghouls can move 11 meters/yards in a combat round.

Sanity Loss: Seeing a Ghoul causes a loss of 0/1D6 Sanity Points.

Great Race of Yith “... immense rugose cones ten feet high, and with head and other organs attached to foot‐thick

distensible limbs spreading from the apexes.” “This … was the greatest race of all; because it alone

had conquered the secret of time.”

– H. P. Lovecraft, “The Shadow Out of Time” (1935)

The Great Race originated on the planet called Yith and came to Earth by transporting their minds

into the bodies of the race they now inhabit. Yithians have a conical form, 10‐feet tall, and 10‐feet

wide at the base. They have black eyes on their round heads, two claw‐like pincers, and a fourth limb

ending in a cluster of weird trumpet‐like appendages. They “walk” by means of expanding and

contracting a viscous layer attached to the base of their bodies.

Yithians have the unique mind transfer ability that allows them to send their minds into the future or

past, inhabiting the bodies of the native races of the era. This is accomplished through a

combination of their own powerful minds and weird science apparatus. The mind of the inhabited

body is sent back to reside in the Yithian’s own body. By this method, the Great Race has filled its

libraries with an immense amount of scientific, historical, and cultural knowledge collected from

across space and time. They command a bewilderingly advanced technical science as well. Their

lightning gun was developed to fight off the Flying Polyps, which they once waged war with.


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STR 12D6 42 39 53

CON 4D6+12 26 22 25

SIZ 8D6+36 64 67 71

INT 4D6+6 20 21 23

POW 2D6+6 13 17 18

DEX 2D6+3 10 12 15

HP derived 45 45 48


Attacks

# Attacks per Round: two pincer attacks or a single burst of the Lightning Gun.

Pincer 40%, damage 1D6 + damage bonus

Lightning Gun 30%, damage Lethality 4% × number of charges spent (see below)

Lightning Gun: This weapon is a camera‐shaped device that shoots powerful bursts of electrical energy. The Great Race manufactured several different varieties; a common variety was powered by an energy pack that may contain up to 32 charges. When firing the Lightning Gun, the firer can choose how many charges to channel into the resulting burst. This can be any amount (up to the number of charges remaining) but whenever a burst contains more than 4 charges there is a chance that an electrical overload will occur, ruining the Lightning Gun. The chance of this occurring is 5% for each charge channeled into the burst beyond 4 (e.g., if 8 charges were channeled the chance of burn out would be 20%). The basic range for a Lightning Gun is 100 yards; for each additional 100 yards reduce the chance to hit by 20% and reduce the gun’s Lethality rating by 3. Reloading a Lightning Gun by fitting a new charge pack takes one round. There is no humanly‐known process of restoring energy to a depleted charge pack.

Defenses

Armor: 8 points of rugged skin.

vs Lethal Damage: PARTIALLY RESILIENT – a successful Lethality roll from a weapon does not kill a member of the Great Race but inflicts normal Hit Point damage equal to the Lethality Rating. Lethal damage from other sources (e.g., explosions, fires) have normal effect.

Special

Spells: Members of the Great Race usually rely on their advanced technology rather than dabbling in Mythos Magic, but a few individuals like to learn a few spells as a kind of hobby.

Time Travel: See H.P. Lovecraft’s “The Shadow Out Of Time” for a detailed description of how members of the Great Race mentally “travels” through time by swapping their minds with people and beings in other eras. Such exchanges always result in curious and inexplicable changes in personality and behavior for the individuals whose bodies are taken over. A mind exchange for the purposes of future/historical study usually lasts about 5 years. There are shadowy groups of people who aid and assist people who are currently occupied by Great Race intelligences.

Movement: Members of the Great Race can move 9 meters/yards in a combat round.

Sanity Loss: Seeing a member of the Great Race of Yith causes a loss of 0/1D6 Sanity Points.


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Gugs “The gugs, hairy and gigantic, once reared stone circles in that wood and made strange sacrifices to

the Other Gods and the crawling chaos Nyarlathotep …”


Gugs are a weird race of giants that dwell predominantly in the Dreamlands. They stand in excess of

20 feet high, are covered in black fur, have long talons, and display a fanged, vertically‐opening maw

that splits the head longitudinally. Gugs are mute and communicate via facial expressions. They

attack with their claws and a vicious bite.


STR 6D6+24 45 44 48

CON 3D6+18 28‐29 26 30

SIZ 6D6+36 57 58 65

INT 2D6+6 13 16 18

POW 3D6 10‐11 11 15

DEX 3D6 10‐11 11 12

HP derived 43 42 48


Attacks

# Attacks per Round: 1. A Gug can either bite, or stomp, or hit with one arm. Each arm has two clawed forearms, so a hit deals two lots of separate damage – one for each claw.

Bite 60%, Damage 1D10

Claws 40%, Damage 4D6 (claw 1) + 4D6 (claw 2); no damage bonus

Stomp 25%, Damage 1D6 + damage bonus

Defenses

Armor: 8 points of sinew and cartilage. vs Lethal Damage: HUGE & TOUGH – Takes only 1 HP damage from attacks with Lethality < 25%; for attacks with higher Lethality Ratings, the Gug takes higher Hit Point Damage. Take the percentile roll made for Lethal Damage, treat each of the dice as a D10 and add them together. This is the amount of Hit Point damage inflicted, less the normal armor rating (minimum 1 HP damage).

Special

Spells: A handful of Gugs know spells; if the individual is of particularly high POW it may know a smattering at the Keeper’s discretion.

Movement: Gugs can move 13 meters/yards in a combat round.

Sanity Loss: Seeing a Gug causes a loss of 0/1D8 Sanity Points.

Hounds of Time

Hounds of Time are interdimensional creatures that appear as large hairless, hyena‐like hounds with

mottled black and green skin and toothy maws. They are able to traverse time and dimensions by

travelling through angles, entering our dimension through any physical angle. By this means, they

will hunt prey relentlessly through time and space. Any beings travelling through time are in great

danger of being scented by the Hounds of Time. They have been known to patrol the ‘corridors’


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which extend between time zones to detect unwelcome individuals who physically or mentally travel

through time. They take great pleasure in pursuing such individuals back to their own time and

devouring them as punishment.

Hounds have a curious relationship with geometry; they can only manifest through material where

two surfaces meet in an angle. They can never materialize via curved surfaces.


STR 3D6+6 16‐17 15 17

CON 3D6+20 30‐31 30 38

SIZ 3D6+6 16‐17 17 19

INT 5D6 17‐18 17 21

POW 7D6 24‐25 22 34

DEX 3D6 10‐11 11 14



Attacks

# Attacks per Round: either one paw attack or one tongue attack (but not both in the same round).

Paw 90%, damage 1D6 + damage bonus + Ichor (see below)

Tongue 90%, damage Power Drain (see below)

Ichor: The entire surface of the Hound is coated in a disgusting blue pus‐like substance. Coming into contact with this ichor when the creature succeeds in an attack may cause poisoning. Treat the pus as a toxin with a Lethality of 6%. If the ichor does not immediately kill the victim, but remains on his or her skin, it will continue to deal the same Hit Point damage each subsequent round. The ichor can be removed by water, fire, or by a towel – although attempting the latter during combat may require a DEX × 5 roll.

Power Drain: When struck by the Hound’s sharp tongue, the victim’s body is pierced by a long and rigid tubular sucker. This causes no Hit Point damage but inflicts an immediate and permanent loss of 1D3 points of POW.

Defenses

Armor: Immune to all non‐magical attacks. Regenerates 4 Hit Points per round unless dead.

vs Lethal Damage: IMMUNE ‐‐ Immune to all non‐magical attacks, including Lethal Damage.

Special

Spells: All Hounds of Time know a selection of relevant spells (the Keeper can choose).

Movement: Hounds of Time can move 8 meters/yards in a combat round on the ground; 50


Sanity Loss: Seeing a Hound of Time causes a loss of 1D3/1D20 Sanity Points.

Hunting Flyers

The hunting flyer is a large, ropy, black serpent‐like being with rubbery wings and appendages with

claws. Its head is malformed and has a mouth with long, sharp teeth. Hunting flyers are not made of

ordinary matter and co‐exist on another plane. Powerful creatures use hunting flyers – which are

capable of speaking the languages of common beings – as messengers.


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STR 5D6+12 29‐30 27 37

CON 3D6 10‐11 14 16

SIZ 5D6+24 41‐42 44 47

INT 1D6+12 15‐16 15 17

POW 6D6 21 11 29

DEX 3D6+3 13‐14 11 17

HP derived 26 29 32

DB N/A N/A N/A N/A

Attacks

# Attacks per Round: can perform both a bite attack and tail tentacle attack in the same round.


Tail Tentacle 90%, damage Tail Grapple (see below)

Tail Grapple: If the tail tentacle of the Hunting Flyer strikes a victim it wraps itself around a limb, effectively PINNING the target (see page 32). A favorite tactic of the Flyer is to grab a victim and then launch into flight. Being held in this way does not inflict any Hit Point damage but the victim is effectively unable to take any actions until he or she is freed. The Hunting Flyer can use its Bite attack against victims held by its tail. Breaking free from the Horror’s grip requires success in an opposed test pitting the creatures STR against the victim’s STR.

Defenses

Armor: 9 points of bubbling matter.

vs Lethal Damage: RESILIENT – a successful Lethality roll does not kill a Hunting Flyer but inflicts normal Hit Point damage. Take the percentile roll made for Lethal Damage, treat each of the dice as a D10 and add them together. This is the amount of Hit Point damage inflicted.

Vulnerability: Takes damage from exposure to light. Bright light inflicts 1 HP per round; bright and dazzling light inflicts 3D6. Full daylight reduces the Hunting Flyer to a pile of grey ash. This damage ignores armor.

Vulnerability: Susceptible to fire, which inflicts double damage. This damage ignores armor.

Special


Movement: Hunting Flyers can move 9 meters/yards in a combat round on the ground; 14


Sanity Loss: Seeing a Hunting Flyer causes a loss of 0/1D10 Sanity Points.

Leng Spiders “There were scenes of old wars, wherein Leng’s almost‐humans fought with the bloated purple

spiders of the neighbouring vales.”


Leng spiders are purple arachnid monstrosities that live in the same realms as the denizens of Leng

(in Earth’s Dreamlands). Their cunning and intellect distinguishes them from common spiders. They

never stop growing and can reach a gargantuan size over the course of a few decades.


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STR 8D6 28 26 36

CON 5D6 17‐18 18 20

SIZ 10D6 35 39 41

INT 3D6 10‐11 9 13

POW 4D6 14 10 15

DEX 3D6+6 16‐17 18 21

HP derived 27 29 31


Attacks

# Attacks per Round: 1 (either one bite or one web toss).

Bite 40%, damage 1D3 + Poison Venom (see below)

Web Toss 60%, damage Entangle in Web (see below)

Poison Venom: The bite of a Leng Spider injects an alien toxin with a Lethality Rating equal to the Spider’s CON.

Entangle in Web: A target that becomes entangled in the web of a Leng Spider is effectively helpless, unable to perform any actions until he or she is freed. The holding strength of the web equals half the Leng Spider’s SIZ – to break free the held victim must win an opposed test which compares his or her STR against this value.

Defenses

Armor: 6 points of chitin.

vs Lethal Damage: LARGE – a successful Lethality roll does not kill a Leng Spider but inflicts normal Hit Point damage equal to the Lethality Rating, less the normal armor rating (minimum 1 HP).

Special


Movement: Leng Spiders can move 8 meters/yards in a combat round.

Sanity Loss: Seeing a normal‐sized Leng Spider causes a loss of 1/1D10 Sanity Points. An especially

large specimen might cause a loss of 1/1D20.

Mi‐Go (The Fungi From Yuggoth) “... invasion from outer space ‐ this time by half‐fungous, half‐crustacean creatures from a planet

identifiable as the remote and recently discovered Pluto; creatures undoubtedly the same as those

figuring in certain whispered hill legends of the north, and remembered in the Himalayas as the Mi‐go …”


Mi‐go are a race of crustaceous humanoid space‐farers who maintain a base on the planet Yuggoth

(Pluto) at the edge of our solar system. They come to Earth to mine minerals and metals they cannot

find elsewhere and are assisted by human conspirators. Mi‐go are uncanny scientists, capable of

creating wondrous machines and performing impossible biological and chemical operations. They

use brain cylinders to maintain not only brains, but the intelligences attached to them.


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Mi‐go are the size of humans, with multiple pairs of wings and insectoid appendages ending in odd

pincers. They may use their forelimbs for locomotion or for carrying objects. In place of a definable

head, Mi‐go have a mass of tentacles which glow in weird lights and seem to be a method of

communication. When speaking to humans, they mimic human voices but with an ever‐present

buzzing or vibrating.

Mi‐go bodies do not show up on normal photographs; they dissolve rapidly once dead.


STR 3D6 10‐11 13 17

CON 3D6 10‐11 14 15

SIZ 3D6 10‐11 11 14

INT 2D6+6 13 17 18

POW 2D6+6 13 13 15

DEX 4D6 14 19 22


DB derived +0 +0 +1D4

Attacks

# Attacks per Round: two nipper attacks or one weapon attack.

Nippers 30%, damage 1D6 + target is grappled (opposed STR vs STR roll to break free)

Weapons as per Keeper’s wishes, including the invention of highly technological weapons.

Defenses

Armor: None, but physical damage only affects a Mi‐go while it is corporeal. If the attack roll used to inflict the damage was an odd number, the attack struck when the creature was out‐of‐phase; such damage is ignored altogether.

Mi‐go may also opt to wear additional Biotech Armor which grants them 5 points of Armor against physical weapons (see page 131).

vs Lethal Damage: OUT OF PHASE – Mi‐go are only sometimes corporeal in our reality. If the roll on the Lethality dice was an odd number, the attack struck at a time when the creature was insubstantial, hence the attack is ignored. Otherwise the Lethal Damage is inflicted as per normal.

Special

Spells: Each Mi‐go has a percentage chance of knowing a few spells equal to its INT × 2.

Space Flight: Mi‐go have the uncanny ability to travel through space, carried on their membranous wings.

Superhuman Surgery: Mi‐go are masters of peculiar and astonishing surgical feats, way beyond what human beings can do. Using such skills, they can remove a human brain from its body and keep it alive in a metal cylinder.

Movement: Mi‐Go can move 9 meters/yards in a combat round on the ground; 11 meters/yards

while flying.

Sanity Loss: Seeing a Mi‐go causes a loss of 0/1D6 Sanity Points.

Moonbeasts “... great greyish‐white slippery things which could expand and contract at will, and whose principal

shape — though it often changed — was that of a sort of toad without any eyes, but with a curious

vibrating mass of short pink tentacles on the end of its blunt, vague snout.”



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The cruel Moonbeasts hail from the dark side of the Dreamlands’ moon and sail black galleys

between their homeland and trade ports of the Dreamlands. Moonbeasts are mute and have no

eyes. Rather, they communicate, see, and smell by use of the mass of tentacles growing from their

snouts. They are sailors and slavers, pirates and traders, and are loathed by other Dreamlands races,

especially the cats of Ulthar who attack Moonbeasts on sight. They arm themselves with spears,

knives, clubs, and axes.


STR 3D6+6 16‐17 16 19

CON 2D6+6 13 10 14

SIZ 3D6+10 20‐21 24 26

INT 2D6+9 16 16 21

POW 3D6 10‐11 8 16

DEX 2D6+3 10 9 15

HP derived 17 17 20


Attacks


Spear 25%, damage 1D10 + 1 + damage bonus

Defenses

Armor: Takes only 1 Hit Point of damage from firearm attacks. Takes full damage from unarmed attack, melee attack, fire, explosion, magic, etc.

vs Lethal Damage: RESILIENT TO FIREARMS – a successful Lethality roll for a firearm attack does not kill a Moonbeast but inflicts normal Hit Point damage. Take the percentile roll made for Lethal Damage, treat each of the dice as a D10 and add them together. This is the amount of Hit Point damage inflicted. Non‐firearm forms of Lethal Damage are handled as per normal.

Special

Spells: Most Moonbeasts know 1‐3 spells (of the Keeper’s choice).

Movement: Moonbeasts can move 9 meters/yards in a combat round.

Sanity Loss: Seeing a Moonbeast causes a loss of 0/1D8 Sanity Points.

Night‐Gaunt “... they were the dreaded night‐gaunts, who never laugh or smile because they have no faces, and

who flop unendingly in the dark betwixt the Vale of Pnath and the passes to the outer world.”

– H. P. Lovecraft, The Dream Quest of Unknown Kadath (1927)

Night‐gaunts live primarily in the Dreamlands, acting as guardians of gates between various

dimensions. When encountered in the mundane world, Night‐gaunts are performing some task or

mission. They have rubbery, black skin, long barbed tails, clawed paws, curving horns, and bat wings.

In place of a typical face, Night‐gaunts have only an emotionless, unadorned, smooth surface.


STR 3D6 10‐11 10 17

CON 3D6 10‐11 8 14

SIZ 4D6 14 14 18


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INT 1D6 3‐4 5 6

POW 3D6 10‐11 9 13

DEX 2D6+6 13 13 15

HP derived 13 11 16


Night‐gaunts usually attack from the wing, swooping upon their enemies to attack with their claws

or their wickedly‐barbed tails. Night‐gaunts are known to employ their barbed tails to perform the

dreaded “tickle” to torture captives, causing the victims to fall into languor.

Attacks

# Attacks per Round: two claw strike attacks, one claw grapple, or one tail‐barb attack.

Claw Strike 30%, damage 1D6 + damage bonus

Claw Grapple 30%, damage target is PINNED (opposed STR vs STR roll to break free)

Tail‐Barb 30%, damage Disorient (see below)

Disorient: If a target is already held by a Night‐gaunt’s claws, it may attempt to drag its curiously‐barbed tail across their skin. This is called a Tail‐Barb attack, and if successful causes a bewildering range of sensations and responses. In some fabulous accounts this is called a “tickle” although it is difficult to imagine the wickedly sharp barbs eliciting much laughter. In general, the result of this attack is that the victim becomes bewildered, confused, and disoriented. This renders them effectively immobilized for the next 1D6+1 rounds.

Defenses

Armor: 2 points of skin.


Special

Notable Skills: Hide 90%, Sneak 90%

Movement: Night‐gaunts can move 7½ meters/yards in a combat round on ground; 15 meters/yards

while flying.

Sanity Loss: Seeing a Night‐gaunt causes a loss of 0/1D6 Sanity Points.

Rat‐Things “... it had long hair and the shape of a rat, but that its sharp‐toothed, bearded face was evilly human …”

– H. P. Lovecraft, “Dreams in the Witch House” (1932)

Small, malignantly intelligent beings that resemble rats with human faces and hand‐like paws, rat‐

things often serve as witches’ familiars. As such, some may have magical abilities or supernatural

connections to their masters.


STR 1D3 2 3 3

CON 2D6 7 8 11

SIZ 1 1 1 1

INT 3D6 10‐11 10 14

POW 2D6 7 9 11

DEX 4D6+4 20 19 21

HP derived 4 5 6

DB derived ‐1D6 ‐1D6 ‐1D6


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Attacks

# Attacks per Round: 1 (Rat‐Things attack by climbing up the legs or arms of human targets or dropping on them from a height).

Bite 35%, damage 1D3 + Cling & Bite (see below)

Cling & Bite: After a Rat‐Thing bites a victim, it will cling to it unless forcibly removed. Each subsequent round inflicts a further 1D3 Hit Points of damage to the victim.

Defenses

Armor: none.

vs Lethal Damage: SUSCEPTIBLE – any Lethal Attack successful against a Rat‐Thing automatically kills it, without the need to roll against Lethality Rating.

Scurrying About: Attempts to hit a Rat‐Thing while it is running about has a ‐40% penalty due to their small size and rapid movement. If the Rat‐Thing is attached to a larger object (e.g., a human victim) this penalty is reduced to ‐20%.

Special


Movement: Rat‐Things can move 11 meters/yards in a combat round.

Sanity Loss: Seeing a Rat‐thing normally causes a loss of 0/1D6 Sanity Points. If, however, the Rat‐

thing has the face of someone the viewer knew in life the loss is higher (1/1D8).

Serpentine Humanoids An ancient race of humanoid snakes that once controlled vast empires, the Serpentine Humanoids were

overthrown by men and driven underground, where they operate weird techno‐sorcery laboratories.

Serpentine Humanoids hate humanity and plot to one day retake the Earth. While there are many

Serpentine Humanoids individuals and small communities around the globe, most remain undetected

due to the creatures’ advanced use of spells rendering their appearance fully human.


STR 3D6 10‐11 11 15

CON 3D6 10‐11 13 18

SIZ 3D6 10‐11 13 16

INT 3D6+6 16‐17 21 23

POW 2D6+6 13 13 15

DEX 2D6+6 13 8 15



Serpentine Humanoids are experienced users of Mythos Magic, and during their long history on

Earth have also constructed a staggering array of different technological devices. This includes

weapons with technical specifications far exceeding human firearms. In combat, Serpentine

Humanoids may employ such advanced weaponry, or simply use readily‐available human weapons.

Attacks

# Attacks per Round: 2 (can bite and use a weapon in the same round).

Bite 35%, damage 1D8 + Toxic Venom (see below)

Weapons (base human chance and damage)

Toxic Venom: The bite of a Serpentine Humanoids injects a potent toxin with a Lethality Rating equal to the individual’s CON.


Page 97

Defenses

Armor: 3 points of scaly skin.

vs Lethal Damage: SUPERHUMAN QUICKNESS – Serpent Humanoids can avoid firearm attacks with a successful Dodge roll. This also applies to Lethal Damage from firearms. If the Dodge roll is not successful, the Serpentine Humanoids is affected by the Lethal Damage as normal. This ability does nothing to avoid Lethal Damage caused by explosions or Magical powers.

Special

Spells: All Serpentine Humanoids know a selection of 2D6 Mythos spells, of the Keeper’s choosing.

Illusion of Human Form: In addition to standard Mythos spells, most Serpentine Humanoids also know forms of magic which can allow them to mask their appearance, making humans see them as other members of the human race.

Movement: Serpentine Humanoids can move 10 meters/yards in a combat round.

Sanity Loss: Seeing a Serpentine Humanoids causes a loss of 0/1D6 Sanity Points.

Shantaks “Winged and whirring, those forms grew larger each moment, and the traveller knew his stumbling was at an end. They were not any birds or bats known elsewhere on earth or in dreamland, for they were larger than elephants and had heads like a horse's. Carter knew that they must be the Shantak‐birds of ill rumour, and wondered no more what evil guardians and nameless sentinels made men avoid the boreal rock desert.

"… It was hard work ascending, for the Shantak‐bird has scales instead of feathers, and those scales are very slippery.

“… a noxious horde of leering Shantaks to whose wings still clung the rime and nitre of the nether pits.”


The Shantak is a huge, red scaly dragon‐like being. Like the mythical wyvern, it has two legs and

wings, but no arms. It lives in mountains and deserts. Some other Mythos species tame Shantaks and

use them as mounts. For some unknown reason, Shantaks fear Night‐gaunts.


STR 4D6+20 34 34 40

CON 2D6+6 13 14 18

SIZ 4D6+36 50 51 56

INT 1D6 3‐4 4 5

POW 3D6 10‐11 12 15

DEX 2D6+3 10 10 13

HP derived 32 28 37


Attacks


Bite 55%, damage 2D6+2

Defenses

Armor: 9 points of hairy chitin.

vs Lethal Damage: RESILIENT – a successful Lethality roll does not kill a Shantak but inflicts normal Hit Point damage. Take the percentile roll made for Lethal Damage, treat each of the dice as a D10 and add them together. This is the amount of Hit Point damage inflicted, less the normal armor rating (minimum 1 HP).


Page 98

Special

Space Flight: Shantaks have the uncanny ability to fly through space, carried on their great leathery wings.

Fear Night‐gaunts: Shantaks have a powerful fear of Night‐gaunts and instantly flee in their presence.

Movement: Shantaks can move 7½ meters/yards in a combat round on the ground; 38 meters/yards

while flying.

Sanity Loss: Seeing a Shantak causes a loss of 0/1D6 Sanity Points.

Shoggoths “It was a terrible, indescribable thing, vaster than any subway train– a shapeless congeries of

protoplasmic bubbles, faintly self‐luminous, and with myriads of temporary eyes forming and

unforming as pustules of greenish light …”


Shoggoths were created by the Elder Things as a highly adaptable and resilient slave race, but over

time the servants gained some semblance of self‐determination and rebelled. Shoggoths are a

globular mass of ever‐changing protoplasm, which continually forms and reforms eyes, mouths,

pseudopods, and other necessary organs. Shoggoths vary in size from the size of a small auto to that

of a train. They can use their sheer bulk to engulf nearby opponents, completely enveloping them.

Engulfed victims suffer, as they are slowly crushed and chewed apart by innumerable mouths.


STR 18D6 63 57 97

CON 12D6 42 31 51

SIZ 24D6 84 73 109

INT 2D6 7 4 9

POW 3D6 10‐11 11 13

DEX 1D6 3‐4 3 4

HP derived 63 52 80


Shoggoths can survive on land as well as in water. Their resistances make them immune to extreme

cold and partially immune to fire and electricity. They are masters of mimicry and speak in a mocking

semblance of the Elder Things’ piping language.

Attacks

# Attacks per Round: 1 area attack (bash or engulf).

Bash 100%, damage Lethality Rating equal to 3% × number of D6s in the Shoggoth’s DB; area of effect = rectangle 5 yards × 1 yard.

Engulf 100%, damage Engulf Victims (see below); area of effect = square 5 yds by 5 yds.

Engulf Victims: If a victim is pulled into the plastic form of the Shoggoth it begins being dismantled by the mouths and suckers internal to the thing’s mass. Each individual trapped inside a Shoggoth must separately make an opposed test comparing his or her STR against the Shoggoth’s STR. If the test is failed, the victim takes Lethal Damage with rating equal to 3% × number of D6s in the Shoggoth’s damage bonus. Targets trapped inside a Shoggoth find it difficult to move or attack the engulfing protoplasm around them: only by making a percentile roll below their STR can such individuals make an attack while inside the beast.


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Defenses

Armor: Takes 1 HP damage from an unarmed attack, melee attack, firearm (including those which are Lethal but have Lethality < 40%), or explosion (with lethality < 40%). Fully immune to damage from fire, acids, electricity and poison. Takes full damage from Magic.

vs Lethal Damage: see above for attacks with Lethality < 40%; for attacks with higher Lethality Ratings, the Shoggoth takes an amount of damage equal to the Lethality Rating.

Regeneration: Regenerates 2 HP per round after being wounded; if the creatures HP ever reach zero it is dead and will not regenerate.

Movement: Shoggoths can move 13 meters/yards in a combat round while rolling along the ground.

Sanity Loss: Seeing a Shoggoth causes a loss of 1D6/1D20 Sanity Points.

Spectral Vampires The Spectral Vampire is a huge mass of pulsing, moving jelly with dozens of scarlet tentacular trunks.

It is an alien creature and can apparently survive in outer space. It is usually invisible, but if it drinks

blood, it becomes partly visible, as the Spectral Vampire lacks the ability to hide the drunken blood

inside its body (until it is metabolized).


STR 4D6+12 26 24 31

CON 2D6+6 13 13 15

SIZ 4D6+12 26 29 32

INT 3D6 10‐11 11 16

POW 1D6+12 15‐16 14 16

DEX 1D6+6 9‐10 10 12

HP derived 20 21 24


Attacks

# Attacks per Round: can attack with 1D4 talons per round, or attempt a bite of a held target.

Talons 40%, damage 1D6 + damage bonus + Grappled (STR vs STR to break)

Bite 80%, damage Blood Drain (see below); only against already grappled targets

Blood Drain: The bite of the Spectral Vampire drains blood from the victim each round until forcibly detached. For each round of blood loss, the victim loses 1D6 STR. If STR reaches zero the victim dies, however if he or she survives the attack, it will be slowly regained at the rate determined by the Keeper.

Defenses

Armor: 4 points of slimy invisible skin.

vs Lethal Damage: NORMAL – affected by Lethal Damage the same way humans are affected. Invisible: Attempts to hit a Spectral Vampire while it is invisible are halved. After feeding, a Spectral Vampire is visible for 1D6 rounds during which this penalty does not apply. When this period expires, the creature has effectively metabolized the blood and returns to being transparent.

Special


Movement: Spectral Vampires can move 7½ meters/yards in a combat round on the ground; 11


Sanity Loss: Seeing a Spectral Vampire or experiencing an attack causes a loss of 1/1D10 Sanity

Points.


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Star‐Spawn of Cthulhu “Another race – a land race of beings shaped like octopi and probably corresponding to the fabulous

pre‐human spawn of Cthulhu – soon began filtering down from cosmic infinity …”


Eons ago, the strange Star‐Spawn descended from the Outer Dark and infested the Earth. They are

varied in form, some are almost entirely octopoid or slug‐like with a mass of tentacles where a face

might be, while the more advanced are humanoid in general shape, with the wings and octopoid

head of their progenitor, Cthulhu.


STR 2D6 × 10 70 90 110

CON 3D6 × 5 50‐55 25 65

SIZ 3D6 × 10 100‐110 100 140

INT 6D6 21 17 31

POW 6D6 21 15 25

DEX 3D6 10‐11 14 16

HP derived 75‐83 63 103


The monstrous Star‐Spawn of Cthulhu are massive and fly via an impossible levitation. Any target

struck by one of their tentacle attacks must fight to avoid being grabbed and immobilized. Grabbed

targets are swallowed whole.

Attacks

# Attacks per Round: either a single claw attack or 1D4 tentacle attacks.

Tentacles 80%, damage = (half damage bonus) + Tentacle Grapple (see below)

Claw 80%, damage = (damage bonus)

Tentacle Grapple: If a tentacle of the Star‐Spawn strikes a victim it attempts to wrap itself around a limb, effectively placing the target in a PIN. Such attacks can be fought using the normal Grapple rules. A favorite tactic of the Spawn is to grab a victim and then pull it into its might maw. A trapped individual can attempt an opposed test pitting his or her STR against the Spawn’s STR to avoid such a terrible fate. Being swallowed inflicts Lethality 50% damage per round.

Defenses

Armor: Takes 1 HP damage from an unarmed attack, melee attack, firearm (including those which are Lethal but have Lethality < 50%), or explosion (with lethality < 50%). Fully immune to damage from fire, acids, electricity and poison. Takes full damage from Magic. vs Lethal Damage: see above for attacks with Lethality < 50%; for attacks with 50%+ Lethality Ratings, a successful attack causes the Star‐Spawn to explode in a disgusting shower of protoplasmic matter. Whether such a scattered Spawn is truly dead, or whether the millions of tiny components will slowly draw themselves together to eventually reform a body is left as a decision for the Keeper.


Special

Notable Skills: Grapple 80%.

Movement: Star Spawn can move 25 meters/yards in a combat round either on the ground or while

swimming.

Sanity Loss: Seeing a Star‐Spawn of Cthulhu causes a loss of 1D6/1D20 Sanity Points.


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Subterranean Land Serpents These enormous underground‐dwelling creatures resemble giant squid with a mass of tentacles at

one end, though it is land‐based. Its huge body is covered by noisome secretions. These curious but

destructive beings have been given a variety of names over history but remain unknown to human

science. The subterranean land serpents burrow through the very crust of the Earth. They can also,

sometimes band together in large groups and manipulate the fabric of the planet in a fashion not

understood. Subterranean land serpents avoid water but are said to be completely immune to any

form of heat and can even resist lava.


STR 3D6 × 5 50‐55 40 60

CON 3D6+30 40‐41 38 45

SIZ 3D6 × 5 50‐55 65 75

INT 5D6 17‐18 24 28

POW 5D6 17‐18 13 23

DEX 2D6 7 8 12


DB derived +5D6 or +6D6

+6D6 +7D6

Attacks

# Attacks per Round: 1‐8 tentacle attacks, or a single crush attack.

Tentacle 75%, damage = (half of damage bonus) + Blood Drain (see below)

Crush 80%, damage = Lethality 15%, to a radius = Serpent’s SIZ ÷ 10 (in yards) Blood Drain: If one of the Land Serpent’s tentacle attacks is successful the pseudopod attaches itself to the victim and continues to drain blood in subsequent rounds, until removed. For each round of blood loss, the victim loses 1D6 CON. If CON reaches zero the victim dies, however if he or she survives the attack, it will be slowly regained at the rate of 1D3 CON per day of quiet rest, up to the original value.

Defenses

Armor: 5 points of thick membrane and gristle.

vs Lethal Damage: RESILIENT – a successful Lethality roll does not kill a Subterranean Land Serpent but inflicts normal Hit Point damage equal to the Lethality Rating, less the normal armor rating (minimum 1 HP).


Special

Mental Control: Some species of Subterranean Land Serpents have the power to control humans via mental dominance. Resolve such attempts as an opposed POW vs POW roll; if the human’s will is overcome, he or she is compelled to remain in close proximity to the area where the mental control was initiated. Once controlled, a dominated human can be mentally contacted by the Land Serpent regardless of where it is, anywhere on Earth. This communication costs the Land Serpent 1 Magic Point. Create Earthquakes: Every Subterranean Land Serpent has the power to cause earthquakes. The magnitude (on the Richter Scale) of the largest quake which a given Serpent can produce is derived by dividing its POW by 4. This strength of earthquake is felt in a 100‐yard radius centered upon the point where the Serpent exercised its power. For the next 100 yards further from that point the quake magnitude is one less (on the Richter Scale), and so on for further 100‐yard increments. Several Subterranean Land Serpents can coordinate to make a larger quake – in that case, simply total the POW of all Serpents and use the same formula above to figure the force of the resulting earthquake.


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Movement: Subterranean Land Serpents can move 7½ meters/yards in a combat round along the

ground or 1½ meters/yards while burrowing.

Sanity Loss: Seeing and adult member of the Subterranean Land Serpents causes a loss of 1D3/1D20

Sanity Points. Witnessing an adolescent causes a loss of 1/1D10. There is no sanity loss for seeing a

hatchling.

Winged Servants “... out of the tartarean leagues … there flopped rhythmically a horde of tame, trained, hybrid winged

things that no sound eye could ever wholly grasp, or sound brain ever wholly remember.”

– H. P. Lovecraft, “The Festival” (1923)

Interstellar creatures that travel the solar winds on furry, membranous wings Winged Servants are

roughly the size of cows with beaked, bat‐like heads and lumpy, mole‐like bodies. Six insectoid

appendages act as legs while their necks and underbellies are bare and scabrous. Mythos scholars

summon Winged Servants via sorcery and use them as steeds.


STR 5D6 17‐18 18 24

CON 3D6 10‐11 12 17

SIZ 5D6 17‐18 21 23

INT 3D6 10‐11 11 16

POW 3D6 10‐11 11 15

DEX 3D6+3 13‐14 16 17



Attacks

# Attacks per Round: May attack with 2 claws per round or a single bite.


Bite 35%, damage 1D6 + Blood Drain (see below)

Blood Drain: If a Winged Servant’s bite is successful it attaches itself to the victim and continues to drain blood in subsequent rounds, until removed. For each round of blood loss, the victim loses 1D6 STR. If STR reaches zero the victim dies, however if he or she survives the attack, it will be slowly regained at the rate of 1D3 STR per day of quiet rest, up to the original value. Winged Servants never voluntarily release a victim until it is completely drained of blood.

Defenses

Armor: 2 points of tough, furry hide


Special

Notable Skills: Listen 50%, Spot Hidden 50%

Spells: At the Keeper’s discretion, Winged Servants with POW 14+ may know a few spells.

Space Flight: Winged Servants have the uncanny ability to travel through space, via an incomprehensible solar flight.

Movement: Winged Servants can move 6 meters/yards in a combat round along the ground or 25


Sanity Loss: Seeing a Winged Servant causes a loss of 1/1D6 Sanity Points.


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Other Creatures and Horrors Not every creature encountered during an Open Cthulhu scenario needs to be a horror of the

Cthulhu Mythos. Some of the dangers may be mundane but deadly wildlife, like lions or crocodiles.

Alternatively, you may decide to introduce some traditional non‐Mythos horrors, such as Ghosts or

Vampires, into your scenarios. The statistics in this section give you a starting point for developing

those types of threats.

Use them either verbatim or tweak them to create your own non‐Mythos (or even cross‐over

Mythos) challenges for the Investigators.

Bear One of the more powerful land mammals, various species of bears are found around the world. A

bear may charge an opponent.


STR 3D6+10 20‐21 19 26

CON 2D6+6 13 10 15

SIZ 3D6+10 20‐21 14 24

POW 3D6 10‐11 10 18

DEX 3D6 10‐11 8 15

HP derived 17 12 20


Attacks

# Attacks per Round: 2 (either 2 claw attacks, or 1 bite and 1 claw).


Claw 40%, damage 1D6 + damage bonus + possible Hold (see below)

Hold: A successful claw attack that rolled an odd number on the attack die also PINS the target as per Grapple (see page 32).

Defenses

Armor: 4 points of fur and hide.


Special

Notable Skills: Climb 30%, Listen 75%, Scent 70%.

Movement: Bears can move 20 meters/yards in a combat round.

Crocodile Crocodiles (and alligators) are found in the rivers and swamps of the tropical climes and conceal

themselves very well. They occasionally become man‐eaters. A crocodile’s keen senses grant

excellent night vision and they have an uncanny camouflage in wilderness terrain.


STR 4D6+12 26 22 31

CON 3D6+8 18‐19 17 20

SIZ 4D6+12 26 19 30

POW 3D6 10‐11 9 15

DEX 2D6 7 7 12




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Attacks


Bite 50%, damage 1D10 + damage bonus + possible Hold (see below)

Death Roll 50%, see below (target must already be held)

Hold: A successful bite attack that rolled an odd number on the attack die also pins the target as per Grapple (see page 32).

Death Roll: If a crocodile has a victim trapped within its jaws, and it is in the water, it can make a death roll twisting and rending the victim. This inflicts 2D6 damage.

Defenses

Armor: 5 points of scaly hide.


Special

Notable Skills: Hide 60%, Stealth 75% (in water) or 50% (on land).

Movement: Crocodiles can move 7½ meters/yards in a combat round along the ground or 10

meters/yards while swimming.

Ghost Ghosts are the spiritual remnant of deceased humans (usually) that manifest in the physical world.

Ghosts may come into being due to evilness in life, particularly powerful emotions, or even sorcery.

Ghosts are normally incorporeal and cannot be affected by normal weapons. Being incorporeal,

ghosts move by floating and can pass through any solid objects without hindrance.

Ghosts generally only possess two statistics: INT and POW. These are derived from the

characteristics of the individual whose death created the ghost (modified over the time that the

ghost has been haunting).

The Sanity Loss to witness a ghostly apparition depends on the specifics of the unnatural

manifestation. The Keeper should determine a reasonable penalty – only the most disturbing and

horrific manifestations should warrant the maximum Sanity Point Loss of 1D8.

A Ghost attacks by enshrouding a victim in its spectral form. The target of the attack and the Ghost

resolve an opposed test of POW vs POW. If the Ghost wins the opposed test, the target loses 1D3

points of permanent POW. If the victim wins the opposed test, the Ghost loses 1D3 POW.

Particularly terrible or ancient Ghosts might inflict 1D6 POW on victims (but still only lose 1D3 if the

test goes against them).

The only way to destroy a Ghost is by reducing its POW to 0.

Great Cat (Lion, Panther, Tiger) Panthers include jaguars, mountain lions, leopards, and other medium‐sized great cats. Lions are

native to Africa but are also common in zoos and circuses, while tigers are found in Asia. All great

cats have keen senses that grant them excellent night vision and powerful senses of smell and

hearing. They can pounce on their prey from up to 20‐feet (7 meters/yards) away.


STR 3D6+9 19‐20 18 26

CON 3D6 10‐11 10 18

SIZ 3D6+6 16‐17 15 21

POW 2D6+6 13 9 16


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DEX 2D6+12 19 18 21



Attacks

# Attacks per Round: 3 (two claws and one bite, or a single ripping rake attack).


Claw 70%, damage 1D8 + damage bonus (if two claws hit same target, it is pinned)

Ripping 80%, damage 2D8 + damage bonus (target must already be pinned)

Defenses



Special

Notable Skills: Hide 80%, Stealth 75%, Track 50%.

Movement: Great Cats can move 15 meters/yards in a combat round.

Mummy Mummies are the embalmed and preserved corpses of ancient people, commonly found in Egyptian

tombs, Andean caves, and more heinous locales. Some mummies have been granted undeath and

protect their tombs with unliving zeal.

Mummies usually attack with their fists but might also be armed with the ancient weapons of their

culture. Mummies created from the corpses of kings, priests, or sorcerers may be much more

powerful than those described here.


STR 3D6 × 2 20‐22 14 30

CON 3D6 × 1.5 15‐17 15 20

SIZ 2D6+6 13 12 15

INT 3D6 10‐11 10 14

POW 1D6+12 15‐16 13 18

DEX 2D6 7 6 8



Attacks

# Attacks per Round: Two fist attacks or one grapple.

Fist 70%, damage 1D6 + damage bonus

Grapple 25%, damage as per Grapple skill

Defenses

Armor: 2 points of leathery skin. Immune to slashing and piercing weapons (including bullets) unless they sever a limb or decapitate the mummy.

vs Lethal Damage: RESILIENT – a successful Lethality roll does not kill a Mummy but inflicts normal Hit Point damage. Take the percentile roll made for Lethal Damage, treat each of the dice as a D10 and add them together. This is the amount of Hit Point damage inflicted, less the normal armor rating (minimum 1 HP).

Vulnerability: Very susceptible to fire due to bitumen in wrappings; once alight, very difficult to extinguish.


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Special

Notable Skills: Stealth 50%, Track 40%.

Movement: Mummies can move 7½ meters/yards in a combat round.

Sanity Loss: Seeing a Mummy causes a loss of 1/1D8 Sanity Points.

Skeleton Skeletons are the horrific animated bones of dead creatures, created through dark magic. They are

mindless, obeying the commands of their creator without wavering.


STR 3D6 10‐11 10 13

CON N/A ‐ ‐ ‐

SIZ 2D6+6 13 10 14

INT 3D6 10‐11 9 16

POW 1 1 1 1

DEX 3D6 10‐11 4 14

HP N/A N/A N/A N/A

DB Derived none none +1D4

Inflicting damage to an animated Skeleton is different to attacking a normal foe, since the breaking

of one or two bones which form sections of its bulk are unlikely to adversely affect it. Rather than

tracking the Skeleton’s Hit Points, all attacks against a Skeleton are treated as Lethal Damage with a

Lethality Rating equal to 4% × the amount of damage inflicted. If the roll against this Lethality is

successful, the Skeleton is instantly killed and dispersed; if the roll fails, the Skeleton suffers no ill

effect.

Attacks

# Attacks per Round:

Hand‐to‐Hand Weapon (DEX × 3)%, damage by weapon type + damage bonus

Defenses

Armor: N/A (see above)

vs Lethal Damage: ALL OR NOTHING – if a Lethal attack rolls under its Lethality Rating the Skeleton is destroyed; otherwise the attack is ineffective and yields no damage.

Sparse: Attacks against an animated Skeleton which rely on piercing or slashing (including firearm attacks) are at half chance due to the many gaps between bones.

Movement: Skeletons can move 9 meters/yards in a combat round.

Sanity Loss: Seeing an animated human Skeleton causes a loss of 0/1D6 Sanity Points.

Snake, Huge (e.g., Python) All snakes have keen senses that allow them to see in low‐light conditions. Vipers haunt swamps and

rainforests and represent any of the smaller venomous snakes, while rattlesnakes are found in North

America. When encountering normal‐sized snakes, the main risk comes from toxic venom. It is rarely

worth running formal combat rounds against such snakes; rather the Keeper should just determine

whether poisoning occurs (to inflict Lethal Damage, see POISON AND DISEASE on page 41).


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Pythons and other large constrictors do not have poison but may constrict victims stuck with its bite

attack. The statistics below should be used for combat encounters involving large snakes of this type.


STR 3D6+12 22‐23 17 27

CON 2D6+6 13 12 15

SIZ 5D6 17‐18 15 24

POW 3D6 10‐11 10 15

DEX 2D6+6 13 11 15



Attacks

# Attacks per Round: 1 grapple or 1 crush.

Grapple 40%, damage victim is pinned; must make STR × 3 roll to free arm to attack

Crush 40%, damage 1D6 + damage bonus each round (must already be Grappled) + Constriction (see below)

Swallow, automatic if victim falls unconscious or does not struggle.

Constriction: An individual who has taken damage from a Crush attack may fall unconscious due to the tight constriction of the Python. Make a CON × 5 roll to avoid blacking out.

Defenses



Special

Notable Skills: Hide 75%, Sneak 90%.

Movement: Huge Snakes can move 7½ meters/yards in a combat round.

Vampire Some of the most powerful of undead creatures, vampires are also one of the most ancient.

Vampires can shape‐change into a gaseous form or into a giant bat at will.

Vampires master the creatures of the night and can summon a horde of bats or wolves. A vampire

may dominate living creatures with its gaze (see below).

Despite their power, vampires have some weaknesses. They can be killed by immersing them in

running water, exposing them to sunlight, or driving a wooden stake through the heart and severing

its head. They retreat from the smell of garlic, the sight of a mirror, or the sight of “good” holy

symbols.


STR 3D6 × 2 20‐22 18 30

CON 2D6+6 13 10 14

SIZ 3D6 10‐11 7 15

INT 2D6+6 13 11 16

POW 2D6+6 13 11 17

DEX 3D6 10‐11 9 14

HP derived 12 9 15



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Vampires are hard to kill. When they are reduced to zero Hit Points, they usually transform into mist

form and retreat to a location where they can use their Regeneration ability to restore themselves.

Only if a Vampire is reduced to 0 HP at the end of a round and at least some of that damage was to

the creature’s head, the Vampire falls to the ground. At this point, a stake driven through its heart

will kill it forever.

Attacks


Bite 50%, damage 1D4 (first round) + Drain Blood (see below)

Claw 50%, damage 1D4 + damage bonus + Drain Magic Points (see below)

Gaze, damage Hypnotize (see below)

Drain Blood: A victim who loses Hit Point damage due to a Vampire’s bite becomes instantly passive, uninterested in pulling free of the creature. For each subsequent round that the Vampire feeds on the victim’s blood, he or she loses 1D6 points of permanent STR. Whether these points are regained by rest is at the Keeper’s discretion.

Drain Magic Points: The touch of a Vampire can drain Magic Points from a victim. Make an opposed test comparing the victim’s current Magic Points versus the Vampire’s MP. If the victim loses the opposed test, 1D3 MPs are lost. These points are added to the Vampire’s MPs. These stolen points are only temporary: if not used by the creature they evaporate in a number of hours equal to the Vampire’s POW.

Hypnotize: The gaze from a Vampire can render a victim in a trance‐like state. When a victim locks eyes with the beast, he or she makes an opposed POW vs POW roll with the fiend. If the target loses the opposed test, a hypnotic state quickly descends. Humans controlled in this way will always follow simple instructions. If the commands are inherently self‐destructive or injurious to the controlled person, an INT × 5 roll can be attempted at the beginning of each round – success means the person snaps out of the trance.

Defenses

Armor: none but see Regeneration below.

vs Lethal Damage: LETHAL ROLL ALWAYS FAILS – regardless of the roll against the Lethality Rating, the Vampire will not be instantly killed but will take damage as per the sum of the dice.

Regeneration: While in its mist form, a Vampire can regenerate 1 Hit Point of damage per round, up to its original value. The same power can be used while the creature is in physical form but the regeneration is much slower – 1 Hit Point per hour.

Special

Notable Skills: Psychology 60%, Scent 75%.

Movement: Vampires can move 12 meters/yards in a combat round.

Sanity Loss: Being attacked by a Vampire causes 0/1D4 Sanity Points. Seeing a vampire transform

from one state to another costs 1/1D3. Vampires who seem human cost no sanity to encounter.

Werewolf Werewolves have haunted the world for eons and are mentioned in the earliest myths of man. Their

relationship to the Mythos is unclear, but some scholars conjecture that lycanthropes of all kinds are

the remaining members of an ancient race. Werewolves can shape‐change from their normal human

form to that of a wolf‐man hybrid or to that of a large wolf at will. The statistics below describe the

wolf form of a Werewolf.


Page 109

Silver is poisonous to Werewolves (see Defenses, below). Victims bitten by a werewolf are at risk of

also contracting lycanthropy.


STR 6D6 21 16 27

CON 2D6+6 13 11 15

SIZ 3D6+1 11‐12 9 17

POW 2D6+6 13 10 17

DEX 2D6+6 13 10 14


DB derived +1D4/6 +1D4 +2D6

Attacks


Bite 30%, damage 1D8 + damage bonus + Lycanthropic Infection (see below)

Lycanthropic Infection: If a Werewolf’s bite breaks a target’s skin, the victim must make a CON × 5 roll to avoid becoming a Werewolf at the next full moon.

Defenses

Armor: 1 point of hide, plus Regeneration (see below).

vs Lethal Damage: SUSCEPTIBLE TO SILVER – treat Lethal Damage dealt by firearms loaded with silver bullets as a special case. Such attacks have their Lethality Rating doubled. All other forms of Lethal Damage are treated as per normal for a human target.


Vulnerability: Silver – Whenever a Werewolf suffers Hit Point damage from an impaling or slashing weapon made of silver (including being shot with a silver bullet), the creature must make an opposed test comparing its CON vs the amount of damage dealt. If it does not win the opposed test, the Werewolf dies instantly. Otherwise the Werewolf takes half the rolled damage and cannot regenerate this Hit Point loss.

Special

Notable Skills: Hide 60%, Track 90%.

Movement: Werewolves can move 15 meters/yards in a combat round.

Sanity Loss: Seeing a Werewolf causes a loss of 0/1D8 Sanity Points. Witnessing a transformation

costs 0/1D3.

Zombie Zombies are animated corpses created through foul necromancy, called up to perform the sorcerer’s

commands. During the ritual to create a Zombie, a point of POW is sacrificed by the spellcaster – this

is the lifeforce that drives the creature. A Zombie has no will of its own and follows the directions it

was given by its creator.


STR 3D6 × 1.5 15‐17 11 23

CON 3D6 × 1.5 15‐17 14 20

SIZ 2D6+6 13 8 17

POW 1 1 1 1

DEX 2D6 7 9 11


DB derived +1D4 none +1D6


Page 110

Attacks



Large Club 25%, damage 1D8+1 + damage bonus

Defenses

Armor: none, but all weapons that work by piercing or slashing only yield 1 HP damage per successful attack. Firearms which do not deliver Lethal Damage, or which deliver Lethal Damage with a rating less than 40%, similarly only yield 1 HP damage. All other forms of non‐magical attack yield half the normal amount.

vs Lethal Damage: see above for firearm attacks with Lethality < 40%; for firearm attacks with higher Lethality Ratings, the Zombie takes an amount of damage equal to the Lethality Rating. The same is true for Lethal Damage caused by explosions. Zombies take no damage from poisons.

Movement: Zombies can move 7½ meters/yards in a combat round.

Sanity Loss: Seeing a Zombie causes a loss of 1/1D8 Sanity Points.


Page 111

NPCs from Lovecraft’s Fiction Lovecraft’s short stories and novellas are packed with personalities which are typical examples of

classic “investigators” of the Cthulhu Mythos. Keepers may wish to drop some of those individuals

into a scenario or campaign as an NPC. The following statistic blocks will assist. However, Keepers

are always advised to go back and re‐read the short stories which introduce the characters as this

will give far greater insight into their quirks and characteristics – much more than a stat block will.

Armitage, Dr. Henry “In the end the three men from Arkham – old, white‐bearded Dr. Armitage, stocky, iron‐grey

Professor Rice, and lean, youngish Dr. Morgan, ascended the mountain alone.”

– H. P. Lovecraft, “The Dunwich Horror” (1928)

STR 11 CON 08 SIZ 12 INT 18 POW 16 DEX 10 CHA 13 EDU 24 SAN 55 HP 10 Damage Bonus: +0

Weapons: none

Skills: Art (Literature) 75%, Cryptography 75%, Cthulhu Mythos 18%, Library Use 95%, Occult 25%,

Other Language (French) 80%, Other Language (German) 70%, Other Language (Greek) 68%, Other

Language (Latin) 75%, Persuade 75%, Psychology 48%.

Carter, Randolph “He knew only that he wished to cross the barrier to the untrammeled land of his dreams and the

gulfs where all dimensions dissolved in the absolute.”

– H. P. Lovecraft and E. Hoffman Price, “Through the Gates of the Silver Key”

(1933)

[also mentioned by Lovecraft in “The Statement of Randolph Carter” (1919), “The Silver Key” (1926),

The Case of Charles Dexter Ward (1927), The Dream Quest of Unknown Kadath (1927)]

STR 15 CON 17 SIZ 15 INT 18 POW 19 DEX 14 CHA 15 EDU 21 SAN 50 HP 15 Damage Bonus: +1D4

Weapons: .45 Revolver 60%, damage 1D10+2 Scimitar 75%, damage 1D8+1 + damage bonus

Skills: Archaeology 14%, Art (Philosophy) 88%, Art (Vintage Books) 79%, Credit Rating 60%, Cthulhu

Mythos 10%, Dreaming 62%, Dream Lore 70%, History 48%, History (Colonial Architecture) 59%,

Library Use 55%, Navigate 65%, Other Language (Cat) 35%, Other Language (Chinese) 25%, Other

Language (French) 57%, Other Language (Zoog) 20%, Own Language (English) 90%, Persuade 55%,

Psychology 70%, Ride 45%.

Notable Possessions: Large silver key, Hyperborean scroll.


Page 112

Curwen, Joseph “the picture was a three‐quarter‐length one … the subject was a spare, well‐shaped man with dark‐blue

coat, embroidered waistcoat, black satin smallclothes, and white silk stockings, seated in a carved chair

against the background of a window with wharves and ships beyond. When the head came out it was

observed to bear a neat Albemarle wig, and to possess a thin, calm, undistinguished face …”

– H. P. Lovecraft, The Case of Charles Dexter Ward (1927)


Weapons: Dagger 35%, damage 1D4 Flintlock Pistol 70%, damage 1D6+1

Skills: Accounting 15%, Anthropology 30%, Bargain 80%, Chemistry 10%, Conceal 60%, Credit Rating

(as Ward) 70%, Cthulhu Mythos 29%, Fast Talk 65%, Hide 45%, History 67%, Library Use 55%, Occult

50%, Occult (Alchemy) 40%, Occult (Astrology) 55%, Other Language (Greek) 45%, Other Language

(Hebrew) 48%, Other Language (Latin) 58%, Persuade 45%, Persuade (Blackmail) 80%, Persuade

(Interrogate) 75%, Persuade (Torture) 75%, Pharmacy 20%, Psychology 70%, Sneak 35%.

Spells: Resurrection, Voorish Sign, plus others.

De La Poer, the last of the “The rats continued their riot, stampeding with such force and distinctness that I could finally assign to

their motions a definite direction. These creatures, in numbers apparently inexhaustible, were engaged in

one stupendous migration from inconceivable heights to some depth conceivably or inconceivably below.”

– H. P. Lovecraft, “The Rats in the Walls” (1923)


Weapons: Claw & Chew 35%, damage 1D4

Skills: Accounting 45%, Bargain 70%, Credit Rating 75%, History 40%, Listen 40%, Listen (Hear Rats)

85%, Psychology 40%, Spot Hidden 55%.

Derby, Edward Pickman “Blond and blue‐eyed, he had the fresh complexion of a child; and his attempt to raise a moustache

were discernible only with difficulty. His voice was soft and light, and his unexercised life gave him a

juvenile chubbiness rather than the paunchiness of premature middle age. He was of good height,

and his handsome face would have made him a notable gallant had not his shyness held him to

seclusion and bookishness.”

– H. P. Lovecraft, “The Thing on the Doorstep” (1933)


Weapons: none


Page 113

Skills: Art (Literature) 60%, Art (Poetry) 85%, Credit Rating 75%, Cthulhu Mythos 33%, Drive

(Automobile) 0%, History 45%, Library Use 65%, Lore (Arkham) 95%, Occult 65%, Persuade 75.

Legrasse, Inspector John Raymond “It must not be fancied that Inspector Legrasse had the least interest in archaeology. On the

contrary, his wish for enlightenment was prompted by purely professional considerations. The

statuette, idol, fetish, or whatever it was, had been captured some months before in the wooded

swamps south of New Orleans during a raid on a supposed voodoo meeting; and so singular and

hideous were the rites connected with it, that the police could not but realise that they had stumbled

on a dark cult totally unknown to them, and infinitely more diabolic than even the blackest of the

African voodoo circles.”

– H. P. Lovecraft, “The Call of Cthulhu” (1926)


Weapons: .38 Revolver 45%, damage 1D10

Skills: Climb 35%, Credit Rating 30%, Cthulhu Mythos 2%, Dodge 34%, History 27%, Law 35%, Library

Use 31%, Listen 80%, Other Language (French) 44%, Other Language (Spanish) 18%, Own Language

(English) 72%, Persuade (Interrogate) 85%, Psychology 70%, Ride 45%, Sneak 39%, Special Gear

(Photography) 22%, Spot Hidden 59%, Track 40%.

Malone, Detective Thomas E. “In youth he had felt the hidden beauty and ecstasy of things, and had been a poet; but poverty and

sorrow and exile had turned his gaze in darker directions, and he had thrilled at the imputations of

evil in the world around. Daily life had fur him come to be a phantasmagoria of macabre shadow‐

studies …”

– H. P. Lovecraft, “The Horror at Red Hook” (1925)


Weapons: Fist/Punch 65%, damage 1D3 + damage bonus Nightstick 38%, damage 1D6 + damage bonus .38 Revolver 70%, damage 1D10

Skills: Bargain 65%, Climb 55%, Credit Rating 35%, Dodge 36%, Drive (Automobile) 35%, Fast Talk

70%, History 30%, Jump 50%, Law 40%, Lore (Streets of New York City) 85%, Library Use 55%, Listen

55%, Occult 16%, Other Language (Greek) 20%, Other Language (Hebrew) 8%, Other Language

(Latin) 38%, Persuade 20%, Psychology 60%, Sneak 25%, Throw 45%.


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Mason, Keziah “Old Keziah, he reflected, might have had excellent reasons for living in a room with peculiar angles;

for was it not through certain angles that she claimed to have gone outside the boundaries of the

world of space we know?”

– H. P. Lovecraft, “Dreams in the Witch House” (1932)


Weapons: Butcher Knife 65%, damage 1D6 + damage bonus

Skills: Astronomy 35%, Cthulhu Mythos 81%, Fast Talk 70%, Hide 65%, History 40%, Occult 65%,

Persuade 85%, Pharmacy 70%, Psychology 50%, Sneak 30%, Sneak (Kidnap) 65%.

Spells: Contact Nyarlathotep, Create Gate, Dread Curse of Azathoth, Voorish Sign, plus others.

Sanity Loss: 0/1D4 SAN to see Keziah Mason.

Brown Jenkin, Keziah’s Familiar

STR 03 CON 05 SIZ 03 INT 14 POW 12 DEX 18 CHA N/A EDU 03 SAN 0 HP 4 Damage Bonus: ‐1D6

Weapons: Bite 80%, damage 1D2

Skills: Hide 85%, Listen 70%.

Sanity Loss: 0/1D4 to see Brown Jenkin.

Pickman, Richard Upton “Pickman was showing what happens to those stolen babes – how they grow up – and then I began

to see a hideous relationship in the faces of the human and non‐human figures. He was, in all his

gradations of morbidity between the frankly non‐human and the degradedly human, establishing a

sardonic linkage and evolution. The dog‐things were developed from mortals!”

– H. P. Lovecraft, “Pickman’s Model” (1926)

[Also mentioned by Lovecraft in “A History of the Necronomicon” (1927), The Dream Quest of

Unknown Kadath (1927)]


Weapons: .45 Revolver 55%, damage 1D10+2

Skills: Art (Oil Painting) 90%, Cthulhu Mythos 12%, Fast Talk 55%, History (Colonial Architecture)

30%, Jump 50%, Other Language (Latin) 25%, Special Gear (Photography) 25%, Psychology 90%.


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Son of Yog‐Sothoth (Wilbur Whateley’s brother) “… it was mostly a kind of force that doesn't belong in our part of space; a kind of force that acts and

grows and shapes itself by other laws than those of our sort of Nature.”


STR 35 CON 30 SIZ 50 INT 21 POW 24 DEX 21 CHA N/A EDU N/A SAN 0 HP 40 Damage Bonus: +2D6

Weapons: Grasp & Suck 100%, damage 1D6 per round (crushing) plus 1D10 each subsequent

round (from blood loss)

Armor: none, but impervious to physical weapons; enchanted weapons do minimum; invisible

except when feeding

Spells: Call Yog‐Sothoth, Voorish Sign, plus others.

Sanity Loss: encountering the Son while it is invisible costs 1/1D8 SAN. While it is visible costs

1D8/3D10 SAN. An individual may lose SAN twice; once for invisible, once for visible.

Waite, Asenath “She was dark, smallish, and very good‐looking except for overprotuberant eyes; but something in

her expression alienated extremely sensitive people. It was, however, largely her origin and

conversation which caused average folk to avoid her. She was one of the Innsmouth Waites, and dark

legends have clustered for generations about crumbling, half‐deserted Innsmouth and its people.”

– H. P. Lovecraft, “The Thing on the Doorstep” (1933)


Weapons: Fist/Punch 60%, damage 1D3 Head Butt 50%, damage 1D4 Grapple 35%, damage special Dagger 45%, damage 1D4+2

Skills: Cthulhu Mythos 72%, Drive (Automobile) 70%, Library Use 70%, Occult 55%, Other Language

(Arabic) 60%, Swim 85%.

Spells: Dread Curse of Azathoth, plus any six “call” and “contact” spells of the Keeper’s choice.

West, Dr. Herbert “a small, slender youth with delicate features, yellow hair, … clean‐shaven, soft‐voiced, and

spectacled, with only an occasional flash of a cold blue eye to tell of the hardening and growing

fanaticism of his character under the pressure of his terrible investigations.”

– H. P. Lovecraft, “Herbert West: Reanimator” (1921)



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Weapons: Scalpel 90%, damage 1D4 Hypodermic 80%, no damage but if attack was a critical success victim injected with

a poison delivering Lethality Rating 20%

Skills: Bargain 75%, Chemistry 65%, Credit Rating 40%, Dodge 55%, Electrical Repair 55%, Fast Talk

50%, First Aid 65%, Hide 40%, Library Use 60%, Listen 5%, Mechanical Repair 45%, Medicine 79%,

Medicine (Anatomy) 80%, Persuade 60%, Pharmacy 60%, Sneak 39%, Special Gear (Photography)

20%, Spot Hidden 70%, Track 18%.

Whateley, “Wizard” “all the rotting ancient books and parts of books which during his own day had been heaped

promiscuously in odd corners of the various rooms. ‘I made some use of 'em,’ he would say as he

tried to mend a torn black‐letter page with paste prepared on the rusty kitchen stove, ‘but the boy's

fitten to make better use of 'em …’”



Weapons: Staff 80%, damage 1D8+1

Skills: Cthulhu Mythos 22%, Drive (Sleigh) 65%, First Aid 25%, History 15%, Library Use 10%, Occult

25%, Persuade 25%.

Spells: Bind Winged Servant, Bind Spectral Vampire, Call Yog‐Sothoth, Contact Nyarlathotep, Dread

Curse of Azathoth, Summon Winged Servant, Summon Spectral Vampire, Voorish Sign, Withering,

plus others.

Whateley, Wilbur “…though he shared his mother's and grandfather's chinlessness, his firm and precociously shaped

nose united with the expression of his large, dark, almost Latin eyes to give him an air of quasi‐

adulthood and well‐nigh preternatural intelligence. He was, however, exceedingly ugly despite his

appearance of brilliancy; there being something almost goatish or animalistic about his thick lips,

large‐pored, yellowish skin, coarse crinkly hair, and oddly elongated ears.”



Weapons: Fist/Punch 65%, damage 1D3 + damage bonus Kick 45%, damage 1D4 + damage bonus Head Butt 55%, damage 1D4 + damage bonus .45 Revolver 30%, damage 1D10+2

Skills: Astronomy 25%, Climb 65%, Cthulhu Mythos 38%, Dodge 55%, Drive (Wagon) 55%, Hide 55%,

History 35%, Jump 65%, Library Use 25%, Listen 90%, Occult 45%, Other Language (Aklo) 65%, Other


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Language (Arabic) 25%, Other Language (Greek) 45%, Other Language (Latin) 65%, Own Language

(English) 75%, Psychology 45%, Sneak 45%, Spot Hidden 75%.

Spells: Bind Winged Servant, Bind Spectral Vampire, Call Yog‐Sothoth, Contact Nyarlathotep, Create

Gate, Powder of Ibn‐Ghazi, Summon Winged Servant, Summon Spectral Vampire, Voorish Sign, plus

others.

Zann, Erich “He was a small, lean, bent person, with shabby clothes, blue eyes, grotesque, satyrlike face, and

nearly bald head.”

– H. P. Lovecraft, “The Music of Erich Zann” (1921)


Weapons: none

Skills: Art (Know Music) 93%, Art (Play Viol) 99%, Listen 90%, Other Language (French) 11%, Other

Language (German) 63%, Other Language (Musical Notation) 99%, Spot Hidden 0%.

Quick NPCs for Open Cthulhu From time‐to‐time the Keeper will need to quickly create game statistics for an NPC that

Investigators encounter in play. In general, most characteristics of an NPC should be average or

unremarkable with just a handful of attributes being exceptional (based on the individual’s role in

the story). The tables below provide a quick way to build NPC stats: the first shows values for the

typical and important attributes based on the individual’s level of seniority or experience. The

second provides some helpful examples of applying those principles to common classes of

professions likely to be encountered by Investigators.

NPC Seniority / Experience Most Stat Ratings

Important Stat Ratings

Most Skill Ratings

Important Skill Ratings

Child / Inexperienced 5 7 None above 10% 20%

Youth / Mildly Experienced 7 9 None above 30% 30%

Novice 10 12 Base 40%

Ordinary / Average 10 12 Base 50%

Expert / Highly Experienced 10 14 Base 60%

NPC Type Important Stats Important Skills

Academic (humanities) INT, EDU Anthropology, Archaeology, Other Language, Occult

Artist, Author, Musician DEX, POW, and/or CHA Art, Persuade, two others

Bureaucrat / Clerical Worker INT Accounting, Law, Library Use, Persuade

Burglar / Thief DEX Climb, Hide, Locksmith, Sneak

Cult Leader POW, CHA Fast Talk, Occult, Persuade, Psychology

Detective or Private Eye CON, INT Law, Persuade, Spot Hidden, Ranged Weapon

Doctor / Nurse INT, EDU Biology, First Aid, Medicine, Pharmacy


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NPC Type Important Stats Important Skills

Farmer / Primary Producer STR, CON Mechanical Repair, Natural World, Ranged Weapon, Ride

Gangster STR, possibly POW Drive, Fist/Punch, Locksmith, Ranged Weapon

Journalist INT, CHA Library Use, Own Language, Special Gear (Photography), Persuade or Fast Talk

Laborer STR Mechanical Repair, Operate Heavy Machinery, Special Gear

Lawyer INT, CHA Accounting, Fast Talk, Law, Persuade

Military (Soldier, Sailor, etc.) CON Climb, Jump, Melee Weapon, Ranged Weapon

Pilot DEX, INT Navigate, Listen, Pilot, Spot Hidden

Police Officer STR, CON Drive, Melee Weapon, Ranged Weapon, Spot Hidden

Psychiatrist, Alienist, or Therapist

INT, EDU Anthropology, Psychoanalysis, Psychology, Persuade

Salesperson / Con Artist / Politician

POW Accounting, Bargain, Fast Talk, Psychology

Scientist INT, EDU Library Use, selection of sciences (Biology, Chemistry, Geology, Pharmacy, Physics)

Technical Expert INT, possibly DEX Locksmith, Electrical Repair, Mechanical Repair, Special Gear


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Grimoire of Mythos Spells As described in CASTING SPELLS (page 71), supernatural effects – or “Magic” – makes an appearance

in several of H.P. Lovecraft’s tales of horror. However, the types of spells that are described are

vastly different from the styles of magic found is most Roleplaying Games, in that they are not flashy

but rather take the form of long and difficult rituals intended to bring about some supernatural

effect. Most of the magic described in Lovecraft’s fiction involves making contact with extra‐

dimensional creatures or gods and attempting to commune with them or compel them to action.

In the spirit of Lovecraft’s conception of magic, the spells described in this Grimoire follow the same

patterns. Spells are divided into seven broad groups:

1. Spells which aim to contact a member of a Mythos race or species and bring it to the

spellcaster’s location (these are called “summoning spells”);

2. Spells which aim to compel a member of a Mythos race or species to follow the instructions

of the spellcaster (these are called “binding spells”);

3. Spells which aim to open mental contact to one of the major Mythos Powers to commune

with the entity or gain wisdom from it (these are called “contact spells”);

4. Spells which aim to open a conduit by which one of the major Mythos Powers may physically

travel to the spellcaster’s location (these are called “calling spells”). Often these spells can

be used in reverse to banish the nominated Mythos Power from the Earth (when used like

this, such spells are called “dismiss spells”);

5. Spells which permit some form of extra‐dimensional or impossibly rapid travel to a far‐

distant location in our Universe or elsewhere (these are called “traversal spells”);

6. Spells which create an invisible barrier of protection which cannot be easily crossed by

certain Mythos creatures and/or Powers (these are called “warding spells”); and

7. Spells which fall into no clear category and provide a miscellaneous set of effects.

Note that while spells in the Grimoire are given standard names in a logical lexicon, this is for game

purposes to make things easier for the Keeper. If these same spells are described as part of in‐world

documents or tomes, they will certainly not be given such mundane titles – rather they will be

described in arcane and vague terms (e.g., “To call forth the great Lord of Wind and Ice”).

The following spells are not intended to be an exhaustive list of every type of magic, but rather a set

of supernatural effects inspired by fiction. These can be used as‐is, or the Keeper can extrapolate

from them to produce new spells applicable to his or her own Open Cthulhu game.

Spells of Summoning In the same way that devotees of the occult sometimes partake in rituals to try to “summon up a

devil from Hell,” there are mad adherents of the Cthulhu Mythos who have created special rituals to

call forth certain alien creatures of the Mythos. Such spells are called “summoning spells” and each

is based upon an elaborate ritual designed to attract one type of Mythos creature – that is, a spell

designed for one species has no influence over any other species.

Despite being discrete and disconnected rituals, all summoning spells are handled in a common way

in terms of the Open Cthulhu game mechanics. Each ritual is led by an individual who must know the

summoning spell and sacrifice at least one Magic Point. He or she may choose to sacrifice more. The

basic chance of the summoning succeeding is 10% per Magic Point spent by the caster. If other

people are participants in the ritual (e.g., performing chants taught to them by the ritual leader),


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they can also choose to sacrifice some of their Magic Points; each point sacrificed adds 2% to the

chance of success.

The ritual lasts 5 minutes for every MP spent by the ritual leader. At the end of that time, all

participants lose 1D3 Sanity and a D100 roll is made against the accumulated success chance derived

from the Magic Points spent. If the roll is below the success chance, a representative member of the

creature species has been compelled to come to the ritual location (either by extra‐dimensional

means or via mundane travel). The creature arrives 2D10 minutes after the ritual has been

completed.

Mythos Creatures summoned using these spells always arrive in an entirely uncontrolled

(“unbound”) state and are as likely to attack the ritual participants as follow their instruction. It is

usually necessary for them to be bound using a separate ritual – see the following section.

The notes below provide some details on some summoning spells known to exist, and specific

requirements or limitations to their casting. This is not intended to be an exhaustive list and the

Keeper is encouraged to invent additional spells of his or her own devising.

MP/POW Sacrifice MPs: Caster’s choice SAN loss 1D3

Summon Dimensional Guardian This ritual involves the use of a dagger which has been created from a pure elemental form of metal

(pure silver, pure iron, etc). If the blade has been enchanted (see ENCHANT ITEM on page 129), each

point of POW invested in the enchanting adds +10 percentiles to the chance of success. Regardless

of this bonus, a fumbled roll still results in failure.

The bonus derived from an enchanted dagger also applies to attempts to bind a Dimensional

Guardian.

Summon Fire Devil This ritual must be performed around a bonfire, or some other large source of open flame.

Constraints: The spell may only be cast at night when the star Fomalhaut is visible above the

horizon.

Summon Hunting Flyer This ritual involves a blood sacrifice of some form of sentient being. The spellcaster does not

perform the sacrifice, rather the poor unfortunate being is left for the Hunting Flyer to devour upon

arrival. If for some reason the sacrifice is no longer present when the Horror arrives, it will target the

spellcaster instead.

Constraints: This spell may only be cast outside at night‐time.

Summon Night‐Gaunt This ritual involves a stone engraved with a specific emblem – the so‐called “Elder Sign” sigil.

Constraints: This spell may only be cast at night, at a time when the moon is not visible in the sky

(new moon, or not yet risen).

Summon Spectral Vampire This ritual involves the use of a written book which contains the words of the spell. If the book has

been enchanted (see ENCHANT ITEM on page 129), each point of POW invested in the enchanting


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adds +10 percentiles to the chance of success. Regardless of this bonus, a fumbled roll still results in

failure.

The bonus derived from an enchanted book also applies to attempts to bind a Spectral Vampire.

Constraints: This spell may only be cast on a clear night, when no clouds obscure the sky.

Summon Winged Servant This ritual involves both a chant and the use of a whistle. If the whistle is enchanted (see ENCHANT

ITEM on page 129), each point of POW invested in the enchanting adds +10 percentiles to the

chance of success. Regardless of this bonus, a fumbled roll still results in failure.

The bonus derived from an enchanted whistle also applies to attempts to bind a Winged Servant.

Constraints: The spell may only be cast when Aldebaran is above the horizon.

Spells of Binding When faced with an uncontrolled member of one of the Cthulhu Mythos species – whether as the

result of a successful summoning or simply via stumbling upon the beast during a scenario –

knowledgeable spellcasters can attempt to “bind” the monstrosity. This brings the creature under

(limited) control of the spellcaster, who is not only immune from its ferocious attacks but may also

direct its activities to an extent.

The list of Binding spells known to exist includes:

Bind Dimensional Guardian

Bind Fire Devil

Bind Hunting Flyer

Bind Night‐Gaunt

Bind Spectral Vampire

Bind Winged Servant

As with summoning spells, the chants to bind each species are different. Thus, knowledge of one

spell does not help when confronted with a different species.

In terms of Open Cthulhu game mechanics, an attempt to bind a creature using a binding spell is

handled as a series of Opposed Tests (see OPPOSED TESTS on page 26). The spellcaster and any

other ritual participants who have been taught the proper chants spend a combat round intoning

the proper words. The spellcaster then spends one Magic Point and all participants lose a point of

Sanity. The spellcaster then makes an Opposed Test comparing his or her current Magic Points with

the MP of the Mythos creature. For some spells, the presence of special artifacts may increase this

chance. If the roll succeeds, the creature is bound. If it fails, the creature will attack the spellcaster.

It is not possible to bind a creature that is currently attacking the spellcaster, or one that is already

bound by somebody else’s binding spell. Also, it is not possible to bind a creature that is far distant

(more than 100 yards away).

A failed casting of a binding spell does not prevent the spellcaster from casting the spell again in a

round when he or she is not the subject of the creature’s attacks.


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Once bound, the creature is compelled to follow one command of the spellcaster’s choosing, after

which it is freed from the spell’s influence. Note that creatures of low intelligence may struggle to

successfully grasp complex instructions; and those of high intelligence may try to find tricky ways to

meet the letter of the instruction rather than the spirit.

MP/POW Sacrifice 1 MP per attempt SAN loss 1 per attempt

Spells to Contact Mythos Powers Small communities of people – usually called “cults” by more mainstream society, if discovered –

worship several of the Mythos Powers. For the unhinged members of these groups, one of the most

revered of all experiences is the chance to mentally commune with their god. This is possible

through a range of rituals called “contact spells.”

Connecting one’s brain to the extra‐dimensional and alien intelligence embodied by a Mythos Power

is an amazingly dangerous thing to attempt. While worshippers hope to reach a kind of spiritual

insight from such an experience, or at least learn key information or hidden secrets, it is just as likely

they will find madness. After all, the Powers of the Mythos have no kinship or interest in humanity

and have no reason to listen to supplications of feeble human minds that claim to “worship” them.

Each of the contact spells described below is a ritual which may potentially grant communion with

one Mythos Power. Knowledge of one spell provides no ability to contact a different Power.

In terms of Game Mechanics, all contact spells are handled in the same way. The spellcaster must

first sacrifice 1 permanent point of POW to initiate the connection attempt. A sanity loss of 1D6 is

applied to anybody who participates in the ritual. Once the point of POW has been subtracted, the

spellcaster should recalculate his or her Luck rating and then attempt to make a roll under half of the

new Luck score. If the roll succeeds, the ritual has succeeded. If it fails, the spellcaster can make

additional attempts, but each requires the sacrifice of 1 POW and 1D6 Sanity.

If the ritual succeeds, mental contact between the spellcaster and the Mythos Power will occur at

sometime within the next few hours or days. The spellcaster has no control over the exact moment

it occurs and may even find themselves in a public place when the moment of communion arrives.

The Keeper should be careful in describing the experience of communing with a Mythos Power; it

should in general be highly abstract and corrosive to sanity. It should also be terrifying. See MENTAL

CONTACT WITH THE INFINITELY ALIEN on page 74 for some guidelines. In terms of game mechanics,

each Mythos Power has a nominated Sanity Loss for mental contact – see the statistic blocks in

MYTHOS POWERS FROM FICTION, beginning on page 76. This Sanity Loss should be applied to the

spellcaster once he or she has made a connection with the Power.

MP/POW Sacrifice 1 POW SAN loss 1D6

Contact Nyarlathotep Constraints: This spell may be cast anywhere, but Nyarlathotep chooses to only make contact at

times when the spellcaster is present at a meeting of “worshippers” or during ceremonies of

initiation to one of his “cults.”

Contact Cthulhu Constraints: This spell may be cast anywhere, but Cthulhu chooses to only make contact with the

spellcaster at night while he or she is dreaming (or having a nightmare).


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Spells to Open Conduits to Mythos Powers (Call/Dismiss) For truly devoted (and usually thoroughly insane) groups that worship a Cthulhu Power, the

opportunity to mentally commune with their god is not enough – their ambition is to come face‐to‐

face with a physical manifestation of their extra‐dimensional master. Over the history of mankind a

few deranged individuals have discovered rituals to open conduits through which Powers can be

brought to earth – these are called “Call” spells. Needless to say, the Mythos Powers which are

obliged by these rituals to manifest on Earth care nothing for the human race nor our planet, and

thus are equally likely to mindlessly destroy everything in the vicinity as listen to their summoner.

Each call spell only has influence over one Mythos Power; it provides no abilities relating to any

other Mythos Power.

There is no known ritual by which any Mythos Power can be “bound” into submission – their power

is simply too vast and too alien to human understanding of the Universe.

The rituals to open a conduit to bring Powers to Earth are long and significant undertakings,

requiring great preparation and a group of trained participants. The spellcaster acts as the ritual

leader. In game terms the caster chooses the number of Magic Points he or she is willing to sacrifice

to fuel the ritual. Each point so sacrificed gives 1% chance of the ritual succeeding. Others

participating in the ritual can each add only one MP; each such point sacrifices also adds 1% to the

chance of success.

For each MP sacrificed in total, the ceremonial chants must continue for at least 1 minute. If the sum

of MPs is greater than 100, duration is 100 minus the excess MPs above 100 MPs. (So, for example if

90 MPs are sacrificed the ritual lasts 90 minutes, but if 120 MPs are sacrificed the ritual takes 100‐20

= 80 minutes).

Once the ritual reaches its climactic conclusion, the spellcaster loses 1D10 Sanity Points; other

participants lose no Sanity directly (although may suffer ill‐effects if the Mythos Power actually

arrives). At this point a D100 is rolled – if the number is less than or equal to the total of sacrificed

MPs, the ritual has succeeded.

MP/POW Sacrifice MPs: Caster’s choice SAN loss 1D10 (caster only)

Dismissing a Mythos Power Call spells can be performed in reverse to attempt to banish the specific Mythos Power back to

wherever it normally dwells. When used in this way the spells are called “Dismiss” spells. Dismissing

a Mythos Power is a difficult thing to achieve and will usually involve a group of people coordinating

their efforts to perform the reverse ritual. For a dismissal to have any chance of success it must be

performed within sight of the physical manifestation of the Power.

In terms of game mechanics, dismiss spells work similarly to call spells: the spellcaster chooses a

number of Magic Points to sacrifice, and other participants can each add 1 MP of their own. The

main difference is the way in which the chance of success is calculated. To have any chance of

success, the total of MP sacrificed must be at least equal to the Mythos Power’s POW divided by 5

(round up). Expending that minimum amount gives 5% chance of success. For every MP above that

amount, a further 5% is added.

Performing a ritual to dismiss a Mythos Power cost no Sanity Points (beyond that inflicted by being

in the vicinity of the Power).


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(So, an attempt to dismiss Nyarlathotep (POW 100) would require at least a sacrifice of 20 MP from

the spellcaster and associates. Such a sacrifice would yield a 5% chance of success, but a sacrifice of

30 MP would grant a 55% chance of success. For a 100% chance of success, the ritual participants

would need to sacrifice 39 MP).

The descriptions below provide special places, items or conditions which must exist before the call

spell can be attempted. Note that these limitations do not apply to the corresponding dismiss spell –

these can be attempted at any time and place.

MP/POW Sacrifice MPs: Caster’s choice SAN loss nil

Call/Dismiss Azathoth Bringing Azathoth to Earth is extremely dangerous and potentially massively destructive; it should

only be attempted in the most dire circumstances.

Constraints: This spell may only be cast outdoors at night.

Call/Dismiss Shub‐Niggurath This ritual involves the construction of a huge stone altar, which must then be consecrated by means

of a time‐consuming process of ritual preparation. This involves thoroughly coating the altar in blood

– the blood from creatures or humans totaling at least 200 SIZ. After consecration, the altar may

potentially be used multiple times over.

The altar must be located in dense woodland where little light filters through. The spellcaster must

stand atop the altar while intoning the incantation. Further blood must be spilled during the actual

ceremony, equivalent to that held within 40 SIZ points of animals or humans.

If properly prepared, the altar adds 20 percentiles to the chance of the ritual succeeding. If there are

any of Shub‐Niggurath’s children present at the site of the ritual, each adds a further 10 percentiles

to the chance of the conduit being successfully opened.

Constraints: This ritual may only be performed at night, at a time when the moon is not visible in the

sky (new moon, or not yet risen).

Call/Dismiss Wendigo This ritual must be performed atop a large mound of snow.

Constraints: This spell can normally only be performed in Arctic or Antarctic climates. It may

potentially be undertaken in other places, but only when the temperature is well below freezing.

Call/Dismiss The Yellow King There are several variants of this ritual, some of which involve the creation of enchanted items or

standing‐stones. For those variants, the correct creation and enchantment (see ENCHANT ITEM on

page 129) add +30 percentiles to the chance of success.

Constraints: This spell may only be cast at night‐time when Aldebaran is visible in a cloudless sky.

Call/Dismiss Yog‐Sothoth This ritual involves the creation of a stone tower at least 30 feet high. During construction, the

spellcaster may sacrifice one or more points of permanent POW to enchant the tower. Once

constructed this tower may be used for multiple castings of the spell. The spellcaster stands atop the


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tower while leading the ritual. He or she must also designate a human sacrifice – this person is not

killed during the ritual but is marked for Yog‐Sothoth to consume once it arrives on Earth.

For each point of POW that was invested during the creation of the tower, an additional +5

percentiles are added to the chance of the ritual succeeding. Note that this bonus may be used

multiple times for different castings of the spell.

Constraints: The tower must be built in an open area. The ritual may only be performed under a

cloud‐free sky.

Spells of Dimensional Traversal Some of the styles of magic described by H.P. Lovecraft and his successors are those which

specifically aim to provide humans with abilities to travel through the vastness of time and space.

Whether these are the products of alien technology or supernatural manipulation of the fabric of

reality is left as a question for the Keeper.

Create Gate There exist techniques by which gateways can be established between two fixed points – perhaps

light‐years apart – that individuals can traverse to achieve instantaneous travel from place‐to‐place.

Whether such portals exist as the result of hyperdimensional science or arcane magic is uncertain.

Rituals exist for the creation of Gates. These all involve the permanent sacrifice of POW, the amount

of the sacrifice being determined by the distance the gateway traverses. The table nearby shows the

POW sacrifice required based on miles traversed by the Gate.

Creating a Gate costs no Sanity.

The exact physical form of a Gate can vary: it might be a curious set of runes carved into a rockface,

an odd arrangement of pebbles on a cave floor, or many other similar configurations.

Any person that comes into contact with the Gate may potentially be drawn into it and transported

to the location at its far end. Travelling in such a way always costs 1 Sanity Point plus a variable

amount of Magic Points (see the table nearby).

If an individual wants to traverse a Gate but has insufficient Magic Points to do so, the Keeper may

rule that he or she simply cannot access the Gate, or alternatively can use POW points in place of

Magic Points, or use Hit Points in place of Magic Points, or some other desperate measure.

There are rumors of more elaborate Gates that can transport individuals to multiple different

locations or transform them during the process of translocation. The creation and operation of such

variants are left for the Keeper to define.

MP/POW Sacrifice to produce

POW: Varies according to the distance traversed

SAN loss to produce

nil

MP/POW Sacrifice to use

MPs: Varies according to distance traversed

SAN loss to use

1 Sanity Point


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<box>Costs to Create and Traverse a Gate

POW to create/ Magic to traverse

Maximum distance (in Miles)

1 100

2 1,000

3 10,000

4 100,000

5 1,000,000

6 10,000,000

7 100,000,000

For each additional point of Magic/Sanity, multiply the maximum distance by 10.

Costs of Gates to Extraterrestrial Places

Place POW to create/ Magic to traverse

Earth’s Moon 5

Mercury 8

Venus 8

Mars 8

Jupiter 8

Saturn 8

Uranus 9

Neptune 9

Pluto (Yuggoth) 9

Proxima Centauri 13

Sirius 13

Fomalhaut 14

Vega 14

Aldebaran 14

Far side of the Milky Way 17

Galaxy M31 (Andromeda) 18

Distant Quasar 25

</box>

Create Time Gate In the same way that techniques exist to create a portal between two locations, other (even more

tightly‐guarded) rituals exist to create gateways which can be used to travel in time.

In game terms, the creation of a Time Gate is much the same as for a regular Gate. However, both

ends of the temporal portal have fixed positions in space and are separated by a fixed period of

time. Thus, for example a Time Gate that was created in 1919 in a basement in Soho and linked to

London of 200 years previous, would remain as a persistent Gate with fixed endpoints and a 200‐

year time differential. If an individual were to enter the Time Gate in 1946 (assuming it hadn’t been

destroyed) he or she would be transported to London of 1746, since that is 200 years prior to the

current year. Traversing the Time Gate in reverse operates in the same way, transporting one the

same fixed number of years in the opposite direction.


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As with regular Gates, the creation of a Time Gate requires the permanent sacrifice of POW, the

amount being dictated by the number of years to be traversed. The geographical distance between

the two endpoints can vary slightly, but typically must be in the same general location (e.g., within

the same city).

Creating a Time Gate costs no Sanity.

Any person that comes into contact with the Time Gate may potentially be drawn into it and

transported to the time and place at its far end. Travelling in such a way always costs 1 Sanity Point

plus a variable amount of Magic Points (see the table nearby).

If an individual wants to traverse a Time Gate but has insufficient Magic Points to do so, the Keeper

may rule that he or she simply cannot access the Time Gate, or alternatively can use POW points in

place of Magic Points, or use Hit Points in place of Magic Points, or some other desperate measure.


POW: Varies according to the years traversed

SAN loss to produce

nil

MP/POW Sacrifice to use

MPs: Varies according to years traversed

SAN loss to use

1 Sanity Point

<box>Costs to Create and Traverse a Time Gate

POW to create/ Magic to traverse

Maximum temporal displacement

1 ± 1 century

2 ± 1,000 years

3 ± 10,000 years

4 ± 100,000 years

5 ± 1 million years



For each additional point of Magic/Sanity, multiply the maximum displacement by 10.

</box>

Spells of Warding and Protection In general, the creatures and Powers of the Cthulhu Mythos are unperturbed by traditional “good

luck” charms or sigils of warding. However, certain arcane symbols – known only to devout Mythos

scholars – can affect some entities to a degree. The creation of such symbols typically requires a

ritual. Two such spells are described below.

Dread Curse of Azathoth The Dread Curse of Azathoth is a ritual incantation which may provide a limited protection against

any being (or individual) which is intelligence and has a deep knowledge of the Cthulhu Mythos. This

includes most creatures of the Mythos. The Dread Curse has no effect on Mythos Powers, however.

The ritual involves simply intoning Azathoth’s secret name – known to only a few. Such deep

knowledge implies the caster is worthy of respect by Mythos entities. For this reason, the spell has


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traditionally been used by Mythos magicians as a way to try to demand respect from upstart Mythos

creatures.

Once the spellcaster has spoken the name, he or she can make an opposed test comparing current

Magic Points with the creature’s Magic Points. If the caster wins the contest, the target of the spell

loses 1D3 permanent points of POW.

Each time this spell is used, and the secret name is spoken, the caster loses 4 Magic Points and 1D6

Sanity Points.

MP/POW Sacrifice 4 Magic Points SAN loss 1D6 Sanity Points

Elder Sign The Elder Sign is an arcane sigil which has power to prevent certain types of Mythos creatures from

passing the barrier or entrance‐way upon which it is carved. The exact form of the Elder Sign is a

source of endless bickering amongst scholars of the Mythos, but all agree that its linear design can

be carved into rocks, on sand, or even into lead seals which serve as stoppers to containers.

Creatures of the Cthulhu Mythos cannot generally touch or pass an Elder Sign once it has been

carved and activated. It has no effect on Mythos Powers, whose power is far too vast to be warded

off by such simple magic.

Although brave scholars have experimented with “portable Elder Signs” that can be worn upon an

individual’s body, these are generally not effective. While an Elder Sign pendant may protect the

piece of skin immediately beneath it, the remainder of the wearer’s body may still be attacked and

devoured by a Mythos creature.

Creating a new Elder Sign requires a complex ritual which requires hours to perform. The spellcaster

must sacrifice 2 points of permanent POW. Creating an Elder Sign costs no Sanity Points.


2 points of POW SAN loss to produce

nil

Voorish Sign The Voorish Sign is a complicated set of hand movements that, when performed in conjunction with

a ritual incantation, has powers to make normally‐invisible Mythos entities temporarily visible. The

movements and incantations only take a few seconds, and the effects are instantaneous.

In addition to its effects on invisible entities, the Voorish Sign also serves to slightly increase the

chance of success of other spells cast at the same time. Any such spellcasting benefits from +5

percentiles to its chance to succeed.

Performing the Voorish Sign ritual costs the spellcaster 1 Magic Point and 1 Sanity Point.

MP/POW Sacrifice 1 Magic Point SAN loss 1 Sanity Point

Miscellaneous Spells The following spells are described in Mythos Tomes and constitute styles of magic that do not

readily fall into the six categories presented above.


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Where necessary for the plot of an Open Cthulhu scenario, the Keeper might consider inventing

additional “miscellaneous magics” of his or her own devising. These should follow the general

guidelines described in GENERAL PRINCIPLES OF MYTHOS MAGIC on page 71. This will avoid

creating “pulp‐like” powers that can easily destroy a carefully‐constructed game of tense Mythos

investigation.

Enchant Item There are, in fact, an entire family of known rituals each intended to imbue an inanimate item with

an aura of magic, thereby making it “enchanted.” When learned from a Mythos Tome (or any other

source), the caster is likely to learn only one of these variants (e.g., “Enchant Knife”). This should be

noted on an Investigator’s character sheet accordingly.

Enchanting an item does not make it perform its mundane purposes any better (e.g., an enchanted

knife does not cut any better than an ordinary one). However, certain other Cthulhu Mythos rituals

require the use of enchanted items and some Cthulhu Mythos creatures have immunity to non‐

enchanted weapons.

The process of enchanting an item, in game terms, involves the spellcaster making some form of

blood sacrifice and sacrificing 1 permanent point of POW. Performing the spell also causes the loss

of 1D4 Sanity Points. The entire ritual consumes about a day.

MP/POW Sacrifice 1 permanent POW SAN loss 1D4 Sanity Points

Powder of Ibn‐Ghazi This ritual allows the spellcaster to create a special powdered concoction which, when blown across

an invisible Mythos entity, will render that entity fully visible to all.

Creating the Powder involves a time‐consuming process. First the spellcaster must collect three

obscure ingredients – the Keeper can decide exactly what these are, and how difficult they are to

obtain. These are compounded together to exacting procedures, while intoning a ritual incantation.

At the end of the process the spellcaster will have one dose of the Powder of Ibn‐Ghazi.

As mentioned above, blowing the powder (whether from one’s hand or through a special tube)

make invisible creatures visible. It also serves to make visible the intangible lines of force that

surround a place consecrated for a Mythos spell or empowered as a Gate.

The effect of the Powder is short‐lived, lasting only ten heartbeats.

Preparing or using the Powder of Ibn‐Ghazi costs no Magic Points or POW, nor does it directly cause

a loss of Sanity – although, naturally, the things it reveals may themselves shake the Sanity of

viewers.

MP/POW Sacrifice nil SAN loss nil (but things made visible may cause losses)

Withering Of all the known spells in the standard Cthulhu Mythos grimoire, this is the closes to an outright

supernatural “attack” on an opponent. The successful application leaves a target blackened by

invisible fire.


Page 130

Casting it consumes two entire rounds, during which the spellcaster must be completely

uninterrupted. The caster can choose how many Magic Points he or she wishes to invest in the spell.

At the end of the incantation, the caster makes an opposed test comparing his or her current MP

total against the target’s MP. If the caster wins the opposed test, the target instantly takes a number

of Hit Points damage equal to the number of MPs spent by the caster. This damage takes the form of

blackening and burning from some unseen source.

Performing the Withering ritual causes the spellcaster to lose Sanity Points equal to half the number

of Magic Points he or she invested in the blast (rounded up).

MP/POW Sacrifice MPs: Caster’s choice SAN loss Half the number of MPs


Page 131

Mythos Artifacts In Lovecraft’s tales, occasional references are made to items with supernatural powers. Rather than

“magic items” in a traditional Roleplaying Game sense, these are usually examples of alien

technology whose use by humans can yield highly‐unpredictable and dangerous results.

The selection below shows a few examples of such Mythos Artifacts which a Keeper can use in his or

her games of Open Cthulhu as desired.

Mi‐Go Biotech Armor Mi‐go scientists mastered bio‐mechanical cybernetics millennia ago and learned to merge

technology with biological material. One use of this technology – bio‐tech armor – is a wearable

device that, once activated, releases a stream of spidery nanobot‐like organisms that cover the

user’s skin.

When active, the biotech armor can offer an Armor rating of 5. It is designed for Mi‐go bodies and if

used by humans will still function but will fuse with the wearer’s flesh. Removing the biotech armor,

even once it is deactivated, costs the human wearer 1D3 damage.

Mi‐Go Brain Cylinders These metal and glass cylinders stand about 1 foot tall and display on their surface a number of

unusual buttons and ports. They are created and used by the mi‐go to hold and transport living

brains. Brains placed within a brain cylinder are basically immortal and can be placed into other

bodies with the proper apparatus. The ports are used to connect the cylinder to brain cylinder

sensory devices, allowing the brain to speak, see, and hear. When not connected to sensory devices,

the brain is in a state of hibernation.

Brain Cylinder Sensory Devices

These weird electronic boxes have cables running from them which may be plugged into brain

cylinders to allow the dormant brain to sense its environment. Separate devices are needed for

speech, vision, and hearing.

Shining Trapezohedron A 4‐inch diameter, roughly spherical black gem with innumerable flat, trapezoid facets, the Shining

Trapezohedron is likely the most powerful artifact to ever curse the Earth. It is traditionally kept in a

rune‐covered box of unearthly, yellowish metal and is activated by staring into its black depths for

one round. After doing so, the user may employ the following powers:

By plunging the Shining Trapezohedron into darkness immediately after activating it, the

Haunter of the Dark (an avatar of NYARLATHOTEP, see page 77) will soon manifest within

the nearest area of complete darkness. The Haunter and summoner will share a mental link,

knowing the location of one another. The Haunter must remain within 300 feet of the

Trapezohedron but will seek to possess the summoner’s body.

The Shining Trapezohedron acts as a window into all time and space. The gazer may view

any time or place of which he knows but is unable to interact with the environment. The

viewing lasts for 1D10+10 rounds. The gazer must make a SAN test (Sanity Loss is up to the

Keeper; recommended at least 1D3/1D6).

Once per month, the Shining Trapezohedron may be used to CONTACT NYARLATHOTEP (as

per the spell, page 122).


Page 132

Yithian Lightning Gun The Great Race of Yith designed these weapons to be used in their war against the Flying Polyps.

These “guns” are camera‐like in shape with one side acting as a handle while the opposite sports a

short, cone‐shaped “barrel.” When the firing switch is depressed, a blast of electrical energy erupts

from the barrel causing 1D10 damage with a range of 100 feet. Each blast uses up a charge; when

found, lightning guns usually have 1D6 charges remaining. See also page 87.


Page 133

Open Gaming License v1.0a The following text is the property of Wizards of the Coast, Inc. and is Copyright 2000 Wizards of the Coast, Inc (“Wizards”). All Rights Reserved. 1. 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System Reference Document, © 2000–2003, Wizards of the Coast, Inc.; Authors Jonathan Tweet, Monte Cook, Skip Williams, Rich baker, Andy Collins, David Noonan, Rich Redman, Bruce R. Cordell, based on original material by E. Gary Gygax and Dave Arneson.

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Eldritch Tales: Lovecraftian White Box Role‐Playing, © 2018, Joseph D. Salvador III

PRODUCT IDENTITY: The following items are hereby identified as Product Identity, as defined in the Open Gaming License Version 1.0a, Section 1(e), and are not Open Game Content: nil. OPEN GAME CONTENT: The following items are hereby designated as Open Gaming Content under the terms of the Open Game License Version 1.0a, Section 1(d): all text and tables.

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