alex graciov and devon gasparotto. overview what is a balanced game? dominant strategies element...

GAME BALANCING

Alex Graciov and Devon Gasparotto

Overview

What is a Balanced Game? Dominant Strategies Element of Chance Making PvP Games Fair Managing Difficulty Understanding Positive Feedback Other Balance Considerations

What is a Balanced Game? A Fair Game

Is not too easy nor too hardMakes player skill the most important factor

in determining success Balance differs between PvP and PvE

Balanced PvE/PvP Characteristics

The Game Provides Meaningful Choices The Role of Chance is Not so Great that

Player Skills becomes Irrelevant

Well-Balanced PvP Charactersitics The Players Perceive the Game to be Fair Any Player who Falls Behind Early in the

Game gets an Opportunity to Catch up The Game Seldom or Never Results in a

Stalemate, Particularly Among Players of Unequal AbilityExample: ChessLeft with King vs King

Well-Balanced PvE Characteristics

The Player Perceives the Game to be FairComplicated due to lack of human players

The Game’s Level of Difficulty Must be Consistent

Dominant Strategies

Strategy is plan for playing a game, according to an approach that player believes will be successful

Dominant Strategy, is a strategy that reliably produces best outcome no matter what opponent does, thus eliminating all other options

Transitive Relationships Among Player Options

Is a relationship between 3 or more entitiesIf A is greater than B and B is greater than

C then A is greater than CMaking A the Dominant StrategyThis imbalance can be fixed by imposing a

Direct Cost on the entities

Direct Cost

Making A cost the most, and B cost more than C will eliminate the Dominant Strategy, forcing the player to choose appropriate strategy depending on the Cost.

Shadow Cost

Costs that are hidden from the playerSmaller fuel tank on the Car, will cause

more money wasted on fuelIn PvE this may seem unfair.

Intransitive Relationships

Rock Paper ScissorsIf A beat B and B beats C, can’t assume A

beats C

Orthogonal Unit Differentiation

Each type of unit should be orthogonally different from all others.

Each unit should display different qualities and possibilities.

A unique feature In war games:

Some units may fly, travel on water, or groundEach unit has it’s on purpose and unique

ability

Design Rule

Differentiate All Your Units

Design Rule

Test Thoroughly to Eliminate Dominant Strategies

Incorporating the Element of Chance Use Chance Sparingly Use in Frequent Challenges with Small

Risks and Rewards Allow Player to Choose Actions to use

Odds to their Advantage Allow Player to Decide How Much to

Risk

Making PvP Games Fair

PvP is fair whenRules give each player equal chance of

winning at startRules don’t allow advantages/disadvantages

to player unequally during game in ways that they cannot influence or prevent outcome

Balancing Games with Symmetry In PvP

All players play by the same rules and try to achieve same victory condition.

Both sides are identical (TF2, CS)

Balancing Asymmetric Games Different players play by different rules Must test mechanics for all combinations

of types of competitors to ensure non-existence of dominant strategies (in-house testers, beta testers)

Testing Sucks!

Project Managers

Developers

Cheating AI and Secret Symmetry Some games have AI that is not good

enough to beat human players This is solved be letting AI cheat (go out

of bound of game rules) to make AI more interesting

This is allowed to a certain extentAs long as the player doesn’t notice or isn’t

too obvious.

The Point Assignment System Assign players identical quantities of

resources or points to delegate to attributes at the beginning

Assigned points to offered units must be orthogonally related

Attributes should scale in the same way to avoid imbalance that may lead to dominant strategy

Starcraft – Perfect Example Perfect example of asymmetrically

balanced game Each race offers flying, construction,

infantry units All units between races cost different

and have different attributes, but all are balanced with each other.

Making PvE Games Fair Game Offers Player Challenges with consistent

difficulty increasing (No sudden spikes) Player should not suddenly lose game without

any warning and through fault of his own (learn by dying, Dark Souls)

Making PvE Games Fair

Stalemate should not occurDeadlock

Game shouldn’t ask player to make critical decisions without adequate information

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

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

Managing Difficulty

Factors Outside Designer’s Control Previous Experience

Uncertain how long player has played similar games

Native TalentPlayer’s natural talent to use during

challenges Multiplayer

Cannot control the player’s opponents’ skill.

Absolute Difficulty

Compare the amount of ISR (intrinsic skill required) to meet challenges and stress it imposes on a trivial challenge of the same typeTwice the difficulty for an enemy with twice

the health

Relative Difficulty

Power ProvidedMeasures player’s strength (player statistics)

Difficulty of a

challenge relative

to the player’s

provided power to

meet that

challenge.

Eg. Skyrim

Relative Difficulty

In Skyrim, the difficulty depends on the player’s Level, the higher it is, the more damage AI enemy inflicts on the player.

So leveling up just on Thief skills (lockpicking, sneaking etc.) and getting a level +80 in the process will not end well for you.

In persistent worlds, warn players against trying a mission that is too difficult

Perceived Difficulty & In-Game Experience

Player learn to handle user interface and mechanics more efficiently as they play

The difficulty the player actually senses The type we are most concerned with

Perceived Difficulty = Relative Difficulty – Player’s experience

where

Relative Difficulty = Absolute Difficulty – Power Provided

The formula doesn’t use quantified values, but can certainly be converted to use.

Creating Difficulty Progression

ConsiderPlayer’s in-game ExperienceIncreasing Power

Perceived Difficulty should not change for young children/infrequent gamers

Evolving the Player

Increase Absolute Difficulty of challenges Increase Power available Ensure player doesn’t gain experience,

such that challenges get easier

Design Rule

Don not jump difficulty from level to level

Difficulty Modes Easy, Medium, Hard

They should not overlap with each other Accounts for native talent and previous

experience

Potentially increase market

Design Rule

Easy Mode Means Easy

Dynamic Difficulty Adjustment Detect player skill and adapt experience Mechanisms:

Performance-EvaluationAdjustment Mechanism

Approaches:Adjust enemies and other characteristics

based on performance

Dynamic Difficulty Adjustment Approaches:

Rubber banding in racing

Training Tutorials

Dynamic Difficulty Adjustment Approaches:

Detect when player is dying frequently and offer bonuses

Positive Feedback

Player achievements changes game to make subsequent achievements easier

Positive Feedback

Examples:Give Advantage to Leader – easier to

maintain leadDiscourage StalemateReward Success, provide Reward in a

Useful form

Control Positive Feedback Should not occur quickly – prevents

players from catching up Ways to control:

Don’t Provide too much power as rewardRestrict player’s powerCosts and Benefits with player

achievements

Control Positive Feedback Ways to Control:

Raise Absolute Difficulty as player proceedsCollaborate against Leader

Control Positive Feedback Ways to Control:

Chance to reduce size of rewardsDefine Victory in terms unrelated to

feedback cycle (i.e. distractions)

Positive Feedback Applied

Avoiding Stagnation

Stagnation: player doesn’t know what to do nextLack of info to proceed

Help Player:Hide clues on how to proceed (in plain sight)Give guidance to wandering

player

Avoid Trivialities

Let Computer handle Can use trivialities, but should be

Infrequent

Make Tuning Easy

Entity has its own mechanicsMust be tuned separately to prevent

imbalance Tweaking should not unpredictably

throw off balance Separate Code from Data