DARK HERESY WARP TRAVEL

INTRODUCTION

The Imperium of mankind is massive on a scale that cannot even be imagined. The distances that can be measured between the planets of the Imperium are such that even the fastest sub-light spaceships, at the mind boggling speeds they are capable of achieving, would take generations to travel between even the closest linked stars. The distances involved are truly, awesomely huge, but the immaterium provides travellers with a means to cover those distances in practical times.

Travel through the immaterium, that alternate reality which exists alongside the physical one of the Imperium, is dangerous and unpredictable, but is also necessary, as it provides the only time-practical way to travel between the stars and planets of the Imperium. To enter the immaterium a ship uses a warp engine, a huge machine that only the most experienced and high ranking tech-priests even begin to understand. The warp engine wraps the ship in a Geller field, a protective energy field that protects the ship from the touch of the warp, and forces the vessel across the barrier that separates the physical world from the immaterium. Once in the immaterium, the ship rides along the flows and eddies of energy that writhe within the warp, being carried along in the waves much like a sailing ship being carried on a wild ocean. Once the ship has travelled the required distance, it falls back into realspace, and a few days in the warp have translated into light years of distance in realspace. By this method, vast distances can be covered. The immaterium is the home of Chaos, the source of the corrupt, twisted, inhuman abominations that plague the Imperium. Its very essence is made up of the stuff of Chaos, and to catch even a glimpse of the roiling madness that makes up the warp can twist and destroy the strongest of human minds, open them to the taint of Chaos and give them over to possession. When a ship is in the immaterium its windows must be covered, so that none on board may accidentally catch a glimpse of the madness around them.

The chart on the last page of this article shows all of the planets of the Calixis Sector. The chart is divided into squares, each measuring 2 light years across. The rules presented here use this 2-light-year square as the basic unit of measurement for space travel.

HOMOPOLAR GENERATORS

A ship that is to be capable of travelling through the immaterium must be equipped with a warp engine, a massive technological wonder beyond the understanding of most people. The power that these engines consume is staggering, and they cannot simply be turned on with the flick of a switch when the ship’s captain decides to enter the warp. They must first be prepared, and their power cells charged up ready for use. The largest part of a warp engine is the Homopolar Generator (HPG); this is where all of the power for the jump is collected, stored and prepared for use.

When a warp jump is imminent, the captain signals for the charging of the HPGs to begin. This process takes a few minutes to complete, as power is drawn into the generator from all over the ship.

Only once the HPG is fully charged is the warp engine capable of summoning a Geller field and folding the ship through the barrier that separates the material world from that of the immaterium.

In game terms, if it is ever required to determine how long an HPG takes to charge, simply roll 1d5, and that is how many minutes it takes. The time is never constant or predictable, due to variations in the levels of power available on the ship at any given time, and environmental factors – like temperature – which affect the machine’s efficiency. Once the HPG is fully charged and ready, it must be used soon. The sheer amount of power stored in the generator and coursing through its coils and conduits, and the immense heat generated while storing that power, starts to damage the containment devices if the power is held captive for too long; cables incinerate, valves blow and seal melt as the energy contained in the HPG strives for release. For every full minute that passes following the charging of the HPG, the GM should roll 1d10. If the number rolled is ever less than the number of rolls that have been made, the generator has lost the power necessary to create a Geller field, the stored energy has started to leak away and dissipate, and the process must be started again.

THE GELLER FIELD Basically, what a warp engine does is envelope the ship in a Geller field; a pulsating sheath of energy which serves three functions. First, the Geller field brings about the folding, warping, twisting and reforming of space around the ship which translates it from the material world into the immaterium. The Geller field’s natural disposition is to translate to the immaterium, and the ship encased within is simply dragged along with it. Once in the immaterium, the Geller field’s second role comes into play. It maintains the stability of the protective aura around the ship, fends off the corrupting touch of the stuff of the warp, and allows the ship to exist – for a short time – in the warp. The third role of the Geller field is that of sail and rudder. Just as sheets of canvas billowing in the wind and wooden rods forced against the waves power and steer a sailing ship through the water, so does the Geller field power a warp ship through the immaterium. The waves and eddies of the warp push at the Geller field, and the malleable surface of the field catches the forces and directs them in such a way that the energy created pushes the ship through the stuff of the warp. Careful manipulation of the Geller field, and controlling how it reacts to the touch of the warp, is what provides control over a ship’s direction of travel through the warp. As soon as a Geller field is activated, it pushes into warp space, tears apart the fabric of reality and allows the materium and immaterium to briefly touch. Once the field has entered the immaterium – taking the ship encased within with it – the wound in reality closes. This translation can only happen as smoothly and seamlessly as it must if the ship is stationary. If the ship is moving when the Geller field is activated, the field will open a gash through reality that will be dragged along with the momentum of the ship, tearing a long rend into the immaterium through which uncontrolled and untapped energy would rush forth with dramatic and dangerous consequences. To prevent this from happening, a warp engine has safety cut-offs built in that prevent a Geller field being created from onboard a moving vessel. WARP ZONES Entering the warp is not a simple matter of powering up a warp engine whenever you want. The massive energies created – and released – can have a dramatic effect on nearby gravitational bodies, and forcing a rend in the materium-immaterium barrier too close to a star can have devastating consequences.

Warp travel protocols, and electronic failsafe systems, mean that warp travel can only happen at a safe distance from a star, or other massive gravitational body. The distance from a star that warp travel becomes safe is known as the warp zone.

Ships leaving a system must first travel a safe distance under their plasma drives before entering the warp, and incoming vessels must likewise drop into real space a safe distance away and trundle in under plasma power.

This stretch of space travel between the inner system and the warp zone is often long and boring. Depending on the size of the local star and the power of a ship’s engines, the warp zone journey can take anything from a week to a few months.

Boredom and lost time are the least of a captain’s worries though, as the warp zone is the hunting ground of pirates. Fleets of marauders and corsairs linger in the outer planets, moons and asteroids of star systems, watching and waiting for likely prey.

One of the common duties of the Imperial Navy is to patrol the warp zones and ward against such space bandits. Important planets will have permanently stationed system patrol craft, but less important and more isolated systems will see only the occasional passing patrol craft.

The Imperial authorities make use of the warp zones themselves to accost other vessels. Customs and security checks are made while ships make the journey through the warp zone. Similarly to the security vessels that ward against pirates, the custom vessels are common at important systems but pass through lesser systems only infrequently. The extent of any given warp zone is determined by many different factors all acting on each other, the most significant factor being the size of the local star, and the extent of the gravity well it therefore projects. The time that will be consumed by a warp zone journey, either inbound or outbound, is determined by the size of the star, and the speed of the ship. The table below summarises the time a warp zone journey will take, is expressed as a number of days, and depends on the size of the local star, and the Very Fast combat speed of the ship. WARP ZONE TRAVEL TIMES Star Ship Speed Size 20 30 40 50 60 70 80 90 100 Tiny 20 18 16 14 12 10 8 6 4 Small 40 36 32 28 24 20 16 12 8 Medium 60 54 48 42 36 30 24 18 12 Large 80 72 64 56 48 40 32 24 16 Huge 100 90 80 70 60 50 40 30 20 Giant 120 108 96 84 72 60 48 36 24

WARP GATES For some reason that human science has never managed to explain, there exists the occasional stable warp gate. These gates provide easy pathways into the warp and doorways to warp routes that can be accessed from inside a warp zone. For a system to have a stable warp gate in close proximity means that vessels coming and going from that system can do so without the need to travel through the warp zone, and wasting all the time and facing the extra dangers which that entails. The economical benefits of a nearby warp gate are obviously tremendous, as merchants, passengers and charter ships can visit without the need for the warp zone journey. With the benefits though, comes a risk: if any enemy fleet were to attack a system via a warp gate, they could do so suddenly and with far greater surprise than would be possible if their ships had to travel through a warp zone on the way.

WARP ROUTES & JUMP POINTS Thankfully, the haphazard nature of the

warp can be tamed a little over time. But only a little, and only over a long time.

Established routes become tamer, less wild and unpredictable. The immaterium along these routes gets trampled down so continually and frequently that a path is worn through the warp and there is less turbulence and crossing flows along these routes. Like a field of long grass blowing wildly in the wind, a path that gets used often will become flattened and easier to traverse.

It is worthy of note here that there is an alternate branch of thought concerning established warp routes. Some theorists maintain that the established routes exist not due to excessive use, but that they have in fact seen heavy use because of their existence. The analogy of a river being a convenient means of transport is the obvious parallel to draw here.

Whatever their origin, whether they were created through use, or used because of their existence, these established routes through the warp link the most important planets with each other, and journey times along these routes are quicker and safer than travel through the warp outside of common routes.

There are 3 degrees of established routes, each providing a quicker and easier path through the warp. Minor routes are those which have been travelled only recently and infrequently; they are not yet widely known or used, and are perhaps used only by local military patrol craft. Common routes are used more often, and have been established for

longer, maybe even for centuries; chartist vessels and military craft use common routes on their cycle of journeys through the years. Major routes are those that link the largest and most important planets of the Imperium, and take centuries of heavy traffic to establish; the capital of a sector will have major routes radiating from it to the other most important planets of the sector. The use of common routes also means that there are well established points of space where warp journeys will be started and ended. When a ship travels through a warp zone on the way to make a jump, it does not head towards a completely arbitrary point in space; it heads for a jump point, the starting point of an established route. Likewise, when the ship leaves the warp at the end of its voyage, it will emerge at a jump point. Imperial security and custom forces can make use of these warp routes and jump points, as there will be well recognised areas of space around a system where ships commonly come and go. Unfortunately, pirates have the same knowledge.

WARP TRAVEL TIMES

The table below can be used to determine how long a journey will take under normal circumstances, outside of the effects of time distortion or poor calculation.

Cross reference the number of squares that are to be travelled with the type of route being used, and the number given is how many days (d) and hours (h) it takes for each square of the route on the Calixis Sector Navigation Chart. Simply multiply the given time by the number of squares being travelled to find the total time the journey will take.

The time given for a journey is always the time that will be experienced by the ship, no matter what time distortion affects the immaterium around the ship and alters the ship’s relation to time in realspace. Seven days in the warp is seven days in the warp, even if only one day or fourteen days have passed in realspace when the ship leaves the warp. A peculiar effect of warp travel is that the longer a ship travels through it, the faster that ship will move. A lengthy jump not only saves time because there is less time spent back in realspace recalculating the next jump, but also because the ship increases warp speed while in the immaterium and covers each subsequent section of a certain length quicker than the previous. Every 10 light years of travel made through the immaterium in a single jump results in an increase in speed.

WARP TRAVEL TIMES PER SQUARE (2 LIGHT YEARS) Length of Jump Route Type Squares Light Years No Route Minor Route Common Route Major Route 1-5 2-10 10d, 4h 8d, 4h 6d, 4h 4d, 4h 6-10 11-20 10d 8d 6d 4d 11-15 21-30 9d, 20h 7d, 20h 5d, 20h 3d, 20h 16-20 31-40 9d, 16h 7d, 16h 5d, 16h 3d, 16h 21-25 41-50 9d, 12h 7d, 12h 5d, 12h 3d, 12h 26-30 51-60 9d, 8h 7d, 8h 5d, 8h 3d, 8h 31-35 61-70 9d, 4h 7d, 4h 5d, 4h 3d, 4h 36-40 71-80 9d 7d 5d 3d 41-45 81-90 8d, 20h 6d, 20h 4d, 20h 2d, 20h 46-50 91-100 8d, 16h 6d, 16h 4d, 16h 2d, 16h 51-55 101-110 8d, 12h 6d, 12h 4d, 12h 2d, 12h 56-60 111-120 8d, 8h 6d, 8h 4d, 8h 2d, 8h 61-65 121-130 8d, 4h 6d, 4h 4d, 4h 2d, 4h 66-70 131-140 8d 6d 4d 2d 71-75 141-150 7d, 20h 5d, 20h 3d, 20h 1d, 20h 76-80 151-160 7d, 16h 5d, 16h 3d, 16h 1d, 16h 81-85 161-170 7d, 12h 5d, 12h 3d, 12h 1d, 12h 86-90 171-180 7d, 8h 5d, 8h 3d, 8h 1d, 8h 91-95 181-190 7d, 4h 5d, 4h 3d, 4h 1d, 4h 96-100 191-200 7d 5d 3d 1d

CALCULATED NAVIGATION The flows of the warp are unsteady and unpredictable. No reference charts can be made of them, and no record kept of their direction or speed, as they are forever changing. Navigation through the warp must be done on the spot immediately prior to the journey being started, and to get exactly where you wish to be, and in a predicted time, is almost impossible. It is a fact of warp travel that the captains of warp ships must accept that they are at the mercy of the warp, and they will be delivered to their destination with an accuracy and time outside of their control. The flows of the warp can be examined by a ship’s sensors while the ship is still in realspace. The route can be plotted according to what can be seen of the warp, and the time that will be required for the warp to carry the ship the required distance calculated based on the speed of the warp’s waves. The ship then enters the immaterium, and gives itself up to the uncertainty of the warp. Once in the immaterium, a ship’s sensors are blind, can detect nothing of the flows of the warp, and it must simply be hoped that the waves are continuing in the same direction, and at the same speed, as they were when the warp was entered. Once the predetermined time has elapsed the ship drops back into realspace; the captain must then calculate the exact location of the ship and work out how far off course it has drifted while in the warp. Due to this uncertainty, ships cannot safely travel great distances by this means of navigation. Going a distance of 4 light years at

a time is generally considered to be the limit of acceptable safety. Due to this limit, it is necessary to make long voyages is short steps, dropping back to realspace to take a bearing and make necessary adjustments to the ship’s heading before making the next jump. When a warp jump is being calculated the person responsible for doing so must make a Navigation (Stellar) skill check. An accurately calculated jump brings the ship out of the warp right where it was intended, but a bad calculation can result in the ship being off course quite dramatically. The Navigation (Stellar) check to calculate a jump has a difficulty assigned to it based on how long the jump being calculated is, as shown on the Calculated Navigation table. CALCULATED NAVIGATION Length of Jump Difficulty 1 Square (2 LY) Easy (+30) 2 Squares (4 LY) Ordinary (+10) 3 Squares (6 LY) Difficult (-10) 4 Squares (8 LY) Very Difficult (-30) 5+ Squares Ridiculous (-50) If the check is passed, the warp jump is calculated successfully and the ship re-enters the materium at the correct point. A failed calculation will result in the ship being off target. The extent of the error depends on how much the Navigation (Stellar) skill check was failed by, and the length of the jump that was being made; a longer jump has a larger margin for going farther off course than

does a smaller jump. The various effects are summarised on the Failed Calculation table, and are expressed as a number of ‘hours’ or ‘squares’.

If a result of ‘hours’ is given, then this time must simply be added to the length of the next jump to bring the ship back in line. In the case of the final jump to reach a system, the ‘hours’ should be added to the length of the warp zone journey to make up for the fact that the ship has come into realspace farther away than planned.

A result of ‘squares’ means that the ship has made a drastic error in its jump, and has actually come into realspace a number of light years away from its intended destination. Roll 1d10 on the Off Target Direction table to determine in what direction the ship is off target. A result of ‘1d5-2’ squares has a minimum result of 1 square. FAILED CALCULATION 1 Square Jump: Fail: 1d5 hours. Fail by 3 Degrees: 1d10 hours. Fail by 5 Degrees: 2d10 hours. 2 Square Jump: Fail: 1d10 hours. Fail by 3 Degrees: 2d10 hours Fail by 5 Degrees: 1 square. 3 Square Jump: Fail: 2d10 hours. Fail by 3 Degrees: 1 square. Fail by 5 Degrees: 1d5-2 squares. 4 Square Jump: Fail: 1 square. Fail by 3 Degrees: 1d5-2 squares. Fail by 5 Degrees: 1d5 squares. 5+ Square Jump: Fail: 1d5-2 squares. Fail by 3 Degrees: 1d5 squares. Fail by 5 Degrees: 1d5+1 squares.

OFF TARGET DIRECTION d10 Direction 1-2 Spinward

3 Diagonal Spinward/Rimward 4 Rimward 5 Diagonal Rimward/Trailing

6-7 Trailing 8 Diagonal Trailing/Coreward 9 Coreward 0 Diagonal Coreward/Spinward

GUIDED NAVIGATION Voyages much longer than the calculated jumps are practical thanks to the Navis Nobilite; the Navigators. The Navigators are a breed apart from normal humankind, vast noble houses tracing their lineage back through the years for as long as the Imperium has existed. The houses are all interlocked with each other through marriage, to keep the Navigator gene alive and unpolluted.

That Navigator gene is what makes them so valuable and necessary to the Imperium. The Navis Nobilite may be called mutants by some people, but their particular mutation is stable, and passed on from parent to child. They have, in the centre of their forehead, a third eye, an eye that is capable of looking upon the warp and reading its flows. As long as they use their third eye, the Navigators are immune to the detrimental visual effects of the warp. They can sit on their observation decks, watch the flow of the warp around the ship and feed information back to the captain and pilot of the ship so that adjustments can be made to keep the ship on course. This alone though is not enough to reliably steer a ship through the warp for long distances; the Astronomican must also be used.

The Adeptus Astronomica on Holy Terra, assembled in a vast choir and guided by the Emperor himself, send out the Astronomican, a pulsing psychic beacon that radiates out from Terra and extends to the outer limits of the Imperium. In fact, it is the limit of the Astronomica which defines the extent of the Imperium; beyond the beacon are the Halo Stars, the outside edge of the Imperium of Mankind.

All Navigators are Psykers, and can pick up on the Astronomican. They use the beacon as a reference point, a directional indicator so that they always know in what direction Holy Terra lies.

By combining the guidance of the Astronomican with their ability to look upon the warp, Navigators can reliably guide ships through the immaterium. Without the Astronomican and the Navigators, the Imperial Navy would simply not be able to reach as far as it does, or to travel quickly enough to maintain the authority of the Emperor.

Most Navigators serve in the Imperial Navy, being bound to the aristocratic officer ranks through long traditions of honour and patronage. When a Navigator is guiding a ship through the warp, he or she must make regular Navigation (Stellar) skill checks to keep the ship on course. Monitoring of the flows of the

warp and listening to the Astronomican are also being done constantly, but these tasks are so intuitive and natural to a Navigator that no skill checks are required to do so; the Navigation (Stellar) skill check is made in order to relate the information thus gathered to realspace charts and guide the ship through the Immaterium to the required destination. For the sake of simplicity and speed, no matter how long a warp journey is, the Navigator must make only a single Navigation (Stellar) skill check to determine how successfully they steer the ship through the voyage. The difficulty of the check is determined by how long the journey is, as shown on the Guided Navigation table.

The result of this check provides a jump time which is expressed, on the Navigation Results table, as a percentage of the time the journey should take as defined by the Warp Travel Times table. A good result means the Navigator has spied a shortcut or beneficial flow and steered the ship into it to take advantage, but a bad roll indicates a miscalculation or mistake by the Navigator which results in the ship’s progress being slowed or veered off course and requiring subsequent correction. GUIDED NAVIGATION Length of Jump Difficulty 1-5 Square (2-10 LY) Easy (+30) 6-10 Squares (12-20 LY) Routine (+20) 11-20 Squares (22-40 LY) Ordinary (+10) 21-30 Squares (42-60 LY) Chall’ing (+0) 31-40 Squares (62-80 LY) Difficult (-10) 41-50 (82-100 LY) Hard (-20) 51+ Squares (102+ LY) V Diff. (-30) NAVIGATION RESULTS Skill Test Jump Time Fail (5 degrees) 150% Fail (4 degrees) 140% Fail (3 degrees) 130% Fail (2 degrees) 120% Fail 110% Pass 100% Pass (2 degrees) 90% Pass (3 degrees) 80% Pass (4 degrees) 70% Pass (5 degrees) 60%

TIME DISTORTION A disturbing effect of travel in the warp is

time distortion. Those on board the ship feel no difference; they experience a warp journey of normal duration, but when they return to realspace they find that more or less time has actually passed than they themselves experienced while in the warp. Sometimes the journey has been made days, weeks, months or even years quicker than expected. It is even possible to arrive at a destination days before the journey was begun. At the other end though, a journey can last longer, even to the rare extent of centuries having passed since the ship entered the warp. When a jump is made, roll d100 on the table below to randomly determine if any time distortion transpires. Those on the ship experience no relative difference in their journey time though; they must determine by themselves how much time has passed in realspace while they were in the warp. The effect given is a modifier that you apply to the journey time to determine what time has passed in realspace (for example, if a jump of 6 days duration was made, and an effect of –d10 days was rolled which resulted in –8, the ship would actually arrive at its destination 2 days before it departed!) Effects far more extreme than this do happen sometimes, but for the purpose of game play this is a manageable limit. Longer distortion times can of course be used by the GM as plot tools. TIME DISTORTION d100 Effect

01 -2d10 days 02 -1d10 days 03 -1d5 days 04-92 No Effect 93 +1d5 days 94 +1d10 days 95 +2d10 days 96 +3d10 days 97 +1d5 months 98 +1d10 months 99 +1d5 years 100 +1d10 years