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FUNDAMENTALS OF GAME DESIGNGAME BALANCING

Sayed AhmedBSc. Eng. in CSc. & Eng.

MSc. in CSc.

http://sayed.justetc.net

http://www.justETC.net

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Presented at the University of Winnipeg, Canada

Just E.T.C for Business, Education, and Technology Solutions

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INTRODUCTION

To be enjoyable A game must

Be well balanced Be not too easy nor too difficult Feel fair to competing players Feel fair to the individual player itself

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TOPICS Qualities of a well balanced game How to balance your game How to set up and balance both

Transitive and intransitive relationships among player choices

Make them simultaneously Interesting and well-balanced

Dominant strategies and how they affect balancing Ways to incorporate chance into games

Where the better player still enjoy better rewards Will focus on two major issues of game balance

Fairness and difficulty Fairness

Player versus player Player versus environment

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TOPICS

Difficulty Player versus environment Various factors that affect the player’s

perception of difficulty How to manage the factors

Role of positive feedbacks How to use it How to control it

Investigate the problems of Stagnation Trivialities

Design games so that the tuning stage is still easier

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WHAT IS A BALANCED GAME

Balanced Game Fair to the player (players) Neither too easy nor too hard Skill of the player is the most important factor to

win the game What makes a balanced game

Several different features together make the game balanced

A collection of design and tuning process create those balancing qualities in a game

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WHAT IS A BALANCED GAME

Techniques for balancing may differ for Player versus player (may be artificial opponent) Player versus environment

A well balanced game posses the following characteristics The game provides meaningful choices The role of chance is not that extreme that player

skill becomes irrelevant Well balanced PvP posses the following

The players perceive the game to be fair Any player who falls behind early in the game gets

reasonable opportunities to catch up again before the game ends

The game seldom or never results in a stalemate

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WHAT IS A BALANCED GAME: PVE

A Well Balanced PvE game posses the following The player perceives the game to be fair The game’s level of difficulty must be consistent

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AVOIDING DOMINANT STRATEGIES

What is a strategy The plan to play the game for victory Can be aggressive Can be defensive Two player may prefer two different strategy Ideally, they should have equal chance of winning

Dominant Strategy A strategy that results the best outcome

A player may achieve No matter what her opponent does

Are undesirable – makes all other choices useless Worse: if one player can use the strategy – others

cannot Happens in asymmetric games

Makes the game unfair

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AVOIDING DOMINANT STRATEGIES

One single choice can be a dominant strategy

Strategies that avoid loss or prevent an opponent from scoring points May qualify as dominant Before 1955, a basket ball player could use

endless tactics - dominant

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DOMINANT STRATEGIES IN VIDEO GAMES

Some video games permit dominant strategies Command and Conquer: Tank Rush Madden NFL Fighting games prone to dominant strategies Fighting and football games

Large number of offensive and defensive actions Difficult to test (for fairness and balancing)

Bad character design may lead to dominant strategies Super street fighter II turbo

Akuma: Air fireball

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TRANSITIVE RELATIONSHIPS AMONG PLAYER OPTIONS

Transitive Relationship among three or more entities A> B, B>C, A>C Example: Strategic options

Aggressive > Defensive > Stealth Aggressive > Stealth Smart player will always choose Aggressive mode

To address the imbalance You may assign direct costs to each strategy

That may lead to players to consider the weak strategies as well Riding horse may be more fun but costlier than riding bi-cycle Traveling with a Hummer will cost more than travelling with Ford

Shadow cost PvE players find shadow costs are unfair

Designers use transitivity to reward players as well Can be back and forth

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INTRANSITIVE RELATIONSHIPS Here the relationships among strategies, or options

are intransitive A beats B, B beats C,

Does not mean that A beats C Rock->paper->Scissors

Paper beats rock, rock beats scissors, scissors beat paper Balanced three way intransitive relationship

Classic design technique to avoid dominant design strategies Forms the basis for balancing player strategies in many games Virtua Fighter 3 (David Sirlin) uses RPS for players movements

Attacking beats throwing, throwing beats blocking, blocking beats attacking

The ancient art of war: RPS three unit types: Knights, Archers, Barbarians K>b, b>a, a>k

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INTRANSITIVE RELATIONSHIPS RPS simple

Not suited to modern war games Offers no interesting choices Needs some variation

Adjust system to produce different benefits Give players different amount of money to win with

Rock, paper, or scissor Target to earn the most money

So make your choices like One choice is better than others in some situations but not in all

Implement it in the core-mechanics Example: Race game: lizard, frog, mouse

Advantages remain slight than overwhelming Course complex mixture of rock, swamp, grass Partial freedom to select routes Add some shadow costs Careful adjustment will make the game balanced

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ORTHOGONAL UNIT DIFFERENTIATION

Each type of unit a player can control in a game Should be orthogonally different from all others Each unit unlike than the others in a different

dimension Not in the same dimension

Race: ford, dodge – speed – differ in only one dimension

Make the units differ in power at one aspect but offer different qualities with each unit To offer a large variety of strategies To make the choice more interesting Every unit should have capabilities that others don’t

have Each unit plays a distinct role Little point to offer weaker units only upgradable to

more powerful unit

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ORTHOGONAL UNIT DIFFERENTIATION

The more diverse your challenges are The easier to offer orthogonally different units Racing games are not good places as all the

players will face similar challenges War games can easily offer orthogonal units

Such units also help to prevent dominant strategies Define the victory condition in such a way

The player must use a variety of different units to win the game

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DOMINANT STRATEGIES IN PVE GAMES One action to surmount all challenges

Makes a dull game Games usually offer more challenges than actions

With a smaller set of actions players can Experiment with the actions to overcome the challenges

Fewer actions does introduce a potential problem Powerful esp.

Actions that can overcome several different kinds of challenges You risk to create exploits Actions so powerful that the player may become unstoppable

No straight forward rule But testing will help Try to play with as many actions and combinations possible to

defeat a challenge Smaller actions offer testability Be careful with power ups and special actions that gives the player

more power than usual

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INCORPORATING THE ELEMENTS OF CHANCE

Use chance sparingly Chance affects only minority of actions

Balance the effect of chance as follows Use chance in frequent challenges with small

risks and rewards Allow the player to choose actions to use the

odds to his advantage Allow the player to decide how much to risk

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MAKING PVP GAMES FAIR

Fairness in PvP Games The rules give each player equal chance of

winning At the beginning of the game The rules do not give advantages or disadvantages to

players unequally during the game in ways that they cannot influence

or prevent apart from the operation of chance

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BALANCING GAMES WITH SYMMETRY

Decide the game to be symmetric or asymmetric At the beginning All PvE games are asymmetric Symmetric PvP games are easier to create Whatever you do for one player

You do it for all players Give similar resources and power in the

beginning Also same condition

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BALANCING ASYMMETRIC GAMES

Fox and Geese Example Testing all possible combinations

Be lengthy

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MAKING PVE GAMES FAIR The game should offer the player challenges at a consistent

maximum levels of difficulty No sudden spikes

The player should not suddenly lose the game Without warning And through no fault of his own Learn by dying

The immortal Give warning of danger

A stalemate should not occur A condition from where both win or lose is impossible

The game should not ask for critical decision without informing the player with all information Monty on the run

All the factual knowledge required to win the game should be contained within the game

The game should not require the player to meet challenges not normally presented in the game’s genre Puzzle in Simulation Game

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MANAGING DIFFICULTY

Flow State Ability balances with the difficulty Peak Productivity

Too Much Challenging Causes anxiety

Too Easy Causes boredom

Absolute Difficulty Perceived Difficulty

The perceived difficulty of a well balanced game should remain within a certain range

Should not have sudden spikes or dips

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OTHER BALANCE CONSIDERATIONS

Balance Consideration Avoiding Stagnation Avoiding Trivialities

Avoiding Stagnation The player is stuck – he does not know what to do The game did not give him enough information to act

Hidden switch concept in first person shooter games PvP: happens rarely

Stagnation can happen if the resource level is too low to act

PvP Hidden boss enemy (after all enemies are destroyed)

Set a separate victory condition Destroy the headquarter

Try to give some guide/hints at stagnation points Gentle nudge

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AVOIDING TRIVIALITIES

Avoid uninteresting details Example

Fuel Consumption, Where to store gold Police Game

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DESIGN TO MAKE TUNING EASY

Design to make tuning easy Use generalized mechanics Separate the code from data Tune the mechanics for each entity separately

Fine tuning your game Modify only one parameter at a time

Changing multiple parameter at once makes it difficult to understand which change affected the outcome

When modifying parameters, make big adjustments, not small ones Double or half the value of a test parameter

Keep records Focused on tester and testing

Be sure your programmers use pseudo-random numbers To regenerate the issue

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MANAGING DIFFICULTY

Perceived Difficulty Hard to compare difficulty level of different types of

challenges Even with the same type of challenges, it’s difficult to

compare difficulty level Complexity differs from person to person

Factors Outside the Control of the Designer How much time the player has spent playing the game Or faced similar challenges in similar games How much native talent the player brings to the game In multiplayer games, it’s the skills of the opponents

that make the game hard or easy Though if the game is fair not much effort to manage difficulty Set difficulty of the challenges as posed by the environment

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TYPES OF DIFFICULTY

It is the perceived difficulty that matters most

To design a challenge of your perceived difficulty You should consider the following

Intrinsic skills required The stress Power provided In-game experience

Absolute Difficulty By using the absolute difficulty

you will be able to compare the difficulty level of different challenges

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TYPES OF DIFFICULTY

Reactive Difficulty and Power Provided In addition to measuring absolute difficulty

You need to measure The power the player has been given

Relative difficulty Difficulty of a challenge relative to the player’s power

to meet the challenge

Perceived Difficulty and In-Game Experience In-game experience:

The amount of time the player has spent to overcome any particular type of challenge

Level designers can keep this in mind for designing the difficulty level of games

Perceived difficulty = absolute difficulty – (power provided + in game experience)

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MANAGING DIFFICULTY

Creating a Difficulty Progression The difficulty should increase with time

Increase absolute difficulty Also increase power of the user

increase relative difficulty as well Make the perceived difficulty also increasing

In a balanced game the perceived difficulty either should not change or will increase

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ESTABLISHING DIFFICULTY MODES

Games with multiple difficulty level The perceived difficulty will not go above a

certain point for a level Action and Action Adventure Games

Designers normally Give the enemies more health, allow them to do more damage Make them more numerous Adjust the AI of the enemies

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DYNAMIC DIFFICULTY ESTABLISHMENT

Max Payne: First Person Shooter game: Adjust enemy power according to player’s

performance Half-life

Check the state of the health of the avatar

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UNDERSTANDING POSITIVE FEEDBACK

Benefits of Positive Feedback Positive feedback discourages stalemate Positive feedback rewards success

Controlling Positive Feedback Don’t provide too much power as a reward for

success Introduce negative feedback Raise the absolute difficulty level of challenges as

the player proceeds Allow collusion against the leader Define victory in terms unrelated to the feedback

cycle Use the effects of chance to reduce the size of the

player’s rewards