Game balancing
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FUNDAMENTALS OF GAME DESIGN GAME BALANCING Sayed Ahmed BSc. Eng. in CSc. & Eng. MSc. in CSc. http://sayed.justetc.net http://www.justETC.net s a y e d @ j u s t e t c . n e t W w w . J u s t E T C . n e t Presented at the University of Winnipeg, Canada Just E.T.C for Business, Education, and Technology Solutions 1
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Transcript of Game balancing
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FUNDAMENTALS OF GAME DESIGNGAME BALANCING
Sayed AhmedBSc. Eng. in CSc. & Eng.MSc. in CSc.http://sayed.justetc.nethttp://www.justETC.net
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Presented at the University of Winnipeg, CanadaJust 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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ww.JustETC.netDOMINANT 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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ww.JustETC.netDOMINANT 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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ww.JustETC.netINCORPORATING 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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ww.JustETC.netUNDERSTANDING 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
