CSCE 590E Spring 2007

Game Design

By Jijun Tang

Announcements

We will NOT have lab on Wednesday Some groups have not sent me the

names First small game is due before spring

break Our first presentation of game design

is scheduled before spring break

Group Ideas

Let’s share some ideas

Definitions

Some time lack standard (concrete) definitions

Game: Object of rule-bound play Play: Interactions to elicit emotions Aesthetics: Emotional responses during play Frame: The border of a game’s context

Inside the frame is in the game Outside the frame is real life

The Language of Games

Why do we play? Not a designer’s problem

What is the nature of games? Not a designer’s problem

How is a game formed of parts? A designer’s problem

Approaching Design

Computer games are an art form Digit arts

Game design practices can be taught You do not need to be genius to design games

Technical discipline like music, film, poetry

Approaching Design

Mental/Cognitive Concepts Beliefs Maps

Examples: Locations Relationships

Mathematical Equations Formulas Algorithms

A model represents something

Approaching Design

Abstract model Conceptual and idealized A tool for investigating specific questions Simplifies thinking to help understand problems May include assumptions thought to be false

Abstract game One rule

The piece is moved to the open square

A Player-Game Model

A model of the player – game relationship

M e c hanic s Inte r fac e Sys te m

P LAYER G AM E

A Player-Game Model

Mechanics Things the player does

Interface Communication between player and

game System

Underlying structure and behavior

Control and State Variables

Control variables Inputs from players

State variables Quantities indicating game state

Play Mechanics

Gameplay Feelings of playing a particular game Activities engaged in a particular game

(Play/game) Mechanics Specific to game activities “What the player does”

Actions

Actions not often in discrete stages Not all actions progress through all

stages

Seven Stages of Action

Execution Intention to act Sequence of action Execution of action

sequence

Evaluation Evaluating

interpretations Interpreting perceptions Perceiving states

P e rc e ivings tate s

Inte rpre t ingpe rc e ptio ns

E valuat inginte rpre tat io ns

E xe c utio n o fac t io n s e que nc e

Se que nc e o fac t io n

Inte nt io nto ac t

G o als

T H E GA M E

Seven Stages of Action

A goal is formed Models the desired state The desired result of an action Examples:

Have a glass of water in hand Capture a queen Taste ice cream

P e rc e ivings tate s

Inte rpre t ingpe rc e ptio ns

E valuat inginte rpre tat io ns

E xe c utio n o fac t io n s e que nc e

Se que nc e o fac t io n

Inte ntio nto ac t

G o als

T H E GA M E

Seven Stages of Action

Goals turned into intentions to act Specific statements of what is to be done

P e rc e ivings tate s

Inte rpre t ingpe rc e ptio ns

E valuat inginte rpre tat io ns

E xe c utio n o fac t io n s e que nc e

Se que nc e o fac t io n

Inte ntio nto ac t

G o als

T H E GA M E

Seven Stages of Action

Intentions put into an action sequence The order internal commands will be performed

P e rc e ivings tate s

Inte rpre t ingpe rc e ptio ns

E valuat inginte rpre tat io ns

E xe c utio n o fac t io n s e que nc e

Se que nc e o fac t io n

Inte ntio nto ac t

G o als

T H E GA M E

Seven Stages of Action

The action sequence is executed The player manipulates control variables

P e rc e ivings tate s

Inte rpre t ingpe rc e ptio ns

E valuat inginte rpre tat io ns

E xe c utio n o fac t io n s e que nc e

Se que nc e o fac t io n

Inte ntio nto ac t

G o als

T H E GA M E

Seven Stages of Action

The state of the game is perceived State variables are revealed via the interface

P e rc e ivings tate s

Inte rpre t ingpe rc e ptio ns

E valuat inginte rpre tat io ns

E xe c utio n o fac t io n s e que nc e

Se que nc e o fac t io n

Inte ntio nto ac t

G o als

T H E GA M E

Seven Stages of Action

Player interprets their perceptions Interpretations based upon a model of the system

P e rc e ivings tate s

Inte rpre t ingpe rc e ptio ns

E valuat inginte rpre tat io ns

E xe c utio n o fac t io n s e que nc e

Se que nc e o fac t io n

Inte ntio nto ac t

G o als

T H E GA M E

Seven Stages of Action

Player evaluates the interpretations Current states are compared with intentions and goals

P e rc e ivings tate s

Inte rpre t ingpe rc e ptio ns

E valuat inginte rpre tat io ns

E xe c utio n o fac t io n s e que nc e

Se que nc e o fac t io n

Inte ntio nto ac t

G o als

T H E GA M E

Designer and Player Models

Systems are built from designer mental models Design models may only anticipate player goals

Designer U ser

Us er 'sM o d el

D es ig nM o d el

S y s tem I m ag e

System

Designer and Player Models

Players build mental models from mechanics Based upon interactions with the system image

The reality of the system in operation Not from direct communication with designers Player and designer models can differ significantly

Designer U ser

Us er 'sM o d el

D es ig nM o d el

S y s tem I m ag e

System

Core Mechanics

Typical patterns of action Fundamental mechanics cycled repeatedly

Examples: Action shooters – run, shoot, and explore Strategy game – explore, expand, exploit, exterminate

referred to as the “four X’s”

Premise

The metaphors of action and setting Directs the player experience

Provides a context in which mechanics fit Players map game states to the premise

Premise

Story is the typical example of premise Time Place Characters Relationships Motivations Etc.

Premise

Premise may also be abstract Tetris operates under a metaphor

The metaphor: arranging colored shapes

Encompasses all game elements Player discussions use the language of

the premise

Premise

Games are models Activities being modeled form premise

Actions may appear similar in model Usually are fundamentally quite different Sports games are good examples:

Playing video games isn’t like playing the sport

Premise

Goes beyond setting and tone Alters the players mental model

Basis of player understanding and strategy Possible: Capable of happening in the real

world Plausible: Possible within the unique world of

premise “Makes sense” within the game’s premise Consistent with the premise as understood

Choice and Outcome

Choice A question asked of the player

Outcome The end result of a given choice

Possibility space Represents the set of possible events A “landscape” of choice and outcome

Choice and Outcome

Consequence or Weight The significance of an outcome

Greater consequences alter the course of the game more significantly

Choices are balanced first by consequence

Choice and Outcome

Well-designed choice Often desirable and undesirable effects Should relate to player goals Balanced against neighboring choices

Too much weight to every choice is melodrama

Orthogonal choices – distinct from others Not just “shades of grey”

Qualities of Choice

Terms in which to discuss choices Hollow – lacking consequence Obvious – leaves no choice to be made Uninformed – arbitrary decision Dramatic – strongly connects to feelings Weighted – good and bad in every choice Immediate – effects are immediate Long-term – effects over extended period Orthogonal – choices distinct from each other

Goals and Objectives

Objectives Designed tasks players must perform

Rigid requirements – formal

Goals An intentional outcome

Notions that direct player action Scales all levels of motivation

From selecting particular strategies… …to basic motor actions (e.g. pressing a button)

Goals and Objectives

Objectives and goals can differ Players goals reflect their understanding of the game Designers must consider how the game communicates with

players Affordances – the apparent ways something can be used

D esigner U serSystem

F in d s w o r dKill d r ag o nR es c u e p r in c es s

F in d s w o r dR es c u e d r ag o nKill p r in c es s

Resources/Economies

Resources Things used by agents to reach goals To be meaningful, they must be…

Useful – provide some value Limited – in total or rate of supply

Economies Systems of supply, distribution, consumption Questions regarding game economies:

What resources exist? How and when will resources be used? How and when will resources be supplied? What are their limits?

Player Strategy

People usually reason with commonsense A view of linear causation – cause and effect

Complex systems do not behave linearly Players need information to support linear

strategy

Situat io n R e s ultAc tio n

Game Theory

Game Theory Branch of economics Studies decision making

Utility A measure of desire associated with an outcome

Payoffs The utility value for a given outcome

Preference The bias of players towards utility

Game Theory

Rational Players Abstract model players – not real people

Always try to maximize their potential utility Solve problems using pure logic Always fully aware of the state of the game

Game Theory

Games of skill One-player games Outcomes determined solely by choices

Games of Chance One-player games Outcomes determined in whole or part by nature (chance)

Games of Strategy Competitions between two or more players

Game Theory

Decision under certainty Players know the outcome of any

decision Risky decisions

Probabilities of nature are known Decision under uncertainty

Probabilities of nature are unknown

Interface

Interface Input, presentation, and feedback.

Input Player to game

Output Game to player

Interface

Contains both hardware, software, and performance elements. Hardware such as game pads Software such as engines Performance such as pressing a button

Graphical user interface (GUI) A visual paradigm of control GUI is the first impression of the game And hard to be cross-platform First: 1984 Macintosh GUI with mouse

Interface

Typical perspectives: First-person Over-the-shoulder (OTS) Overhead (top-down) Side Isometric

First person

OTS

Overhead and Side

Isometric

Audio Interface

General categories of audio Music

Powerful tool for establishing mood and theme

Pay attention to license issues The campus is cited 960 times last year

Sound effects Dialog

Input Interface

Controls Physical input devices: mouse, key,

motion, etc Control inputs

User manipulations of the controls They are not strategies

Example: a sequence of buttons to perform a combo

Strategies involve deciding when to perform

Keys

Key map or control table A diagram showing control input, action,

and context Mapping: An understood relationship

between two things Map keys by looking at your own hand Suit your targeted players: small/big

Key maps

Complex games have many keys and combinations

Ship your game with a detailed key map Control diagrams

Show input, action, and context

Example

Front End Interface

Front-end In application software

The visible portion of the application In games

GUI elements not displayed during play Used mainly for input/configure/choice

Hud Interface

HUD (Head-Up Display) Displays during play

Shows and other information difficult to present directly in the game environment

Examples Scores Resource levels Mini Map Chat Alerts Level

Huds