F UNDAMENTALS OF G AME D ESIGN G AME B ALANCING Sayed Ahmed BSc. Eng. in CSc. & Eng. MSc. in CSc Presented at the University of Winnipeg, Canada Just E.T.C for Business, Education, and Technology Solutions 1

I NTRODUCTION 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 2

T OPICS 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 3

T OPICS 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 4

W HAT IS A B ALANCED G AME 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 5

W HAT IS A B ALANCED G AME 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 6

W HAT IS A B ALANCED G AME : P V E 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 7

A VOIDING D OMINANT S TRATEGIES 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 8

A VOIDING D OMINANT S TRATEGIES 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 9

D OMINANT STRATEGIES IN V IDEO G AMES 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 10

T RANSITIVE RELATIONSHIPS AMONG P LAYER O PTIONS 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 11

I NTRANSITIVE 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 12

I NTRANSITIVE 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 13

O RTHOGONAL U NIT D IFFERENTIATION 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 14

O RTHOGONAL U NIT D IFFERENTIATION 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 15

D OMINANT S TRATEGIES IN P V E G AMES 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 16

I NCORPORATING THE E LEMENTS OF C HANCE 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 17

M AKING P V P G AMES F AIR 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 18

B ALANCING G AMES WITH S YMMETRY 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 19

B ALANCING A SYMMETRIC G AMES Fox and Geese Example Testing all possible combinations Be lengthy 20

M AKING P V E G AMES F AIR 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 21

M ANAGING D IFFICULTY 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 22

O THER B ALANCE C ONSIDERATIONS 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 23

A VOIDING T RIVIALITIES Avoid uninteresting details Example Fuel Consumption, Where to store gold Police Game 24

D ESIGN TO M AKE T UNING E ASY 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 25

M ANAGING D IFFICULTY 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 26

T YPES OF D IFFICULTY 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 27

T YPES OF D IFFICULTY 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) 28

M ANAGING D IFFICULTY 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 29

E STABLISHING D IFFICULTY M ODES 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 30

D YNAMIC D IFFICULTY E STABLISHMENT 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 31

U NDERSTANDING P OSITIVE F EEDBACK 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 32