2.1 game design

1. Chapter 2.1
Game Design

2. 2
Overview
 Game design as…
 full-time occupation is historically new
 field of practical study – even newer

3. 3
Overview
 Folk games [Costikyan]
 “Traditional” games with cultural origins
 Examples:

Tic-Tac-Toe (Naughts and Crosses)

Chess

Go

Backgammon

Poker

4. 4
Overview
 This introduction covers:
 Terms
 Concepts
 Approach
 All from a workaday viewpoint

5. 5
Overview
 There is no one “right” way to design
 There are many successful approaches
 Specific requirements and constraints of
each project and team determine what
works and what does not.
 This introduction is but a scratch

6. 6
The Language of Games
 Game development – a young industry
 Standards are still being formulated
 Theory
 Practice
 Terminology

7. 7
The Language of Games
 Debate continues over high-level views
 Lack of standard (concrete) definitions
 Game
 Play
 High-level concepts tricky to articulate

8. 8
The Language of Games
 Workplace differences usually low-level
 Working terminology

Example
 “actors” instead of “agents”
 “geo” instead of “model”
 Workflow – how things get done

Individual responsibilities

Processes under which work is performed

9. 9
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

10. 10
The Language of Games
 Our simplistic high-level definitions
 Easy to modify to fit multiple cultures
 Practical over metaphysically true
 play
 game
 aesthetics

11. 11
Play and Game
 Play
 Interactions to elicit emotions
 Game
 Object of rule-bound play
 General enough to cover everything

12. 12
Aesthetics and Frame
 Aesthetics
 Emotional responses during play

Naïve practical approach, not classical
 Frame
 The border of a game’s context

Inside the frame is in the game

Outside the frame is real life

13. 13
Approaching Design
 Computer games are an art form
 Game design practices can be taught
 Technical discipline like music, film, poetry
 The art of making dynamic models

14. 14
Approaching Design
 Mental/Cognitive
 Concepts
 Beliefs
 Maps

Examples:
 Locations
 Relationships
 Mathematical
 Equations
 Formulas
 Algorithms
 A model represents something

15. 15
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

16. 16
A Player-Game Model
 A model of the player – game relationship
M e c h a n i c s I n t e r f a c e S y s t e m
P L A Y E R G A M E

17. 17
A Player-Game Model
 Mechanics
 Things the player does
 Interface
 Communication between player and game
 System
 Underlying structure and behavior

18. 18
Control and State Variables
 Defined by Isaacs in Differential Games
 Control variables
 Inputs from players
 State variables
 Quantities indicating game state

19. 19
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”

20. 20
Seven Stages of Action
 Execution
 Intention to act
 Sequence of action
 Execution of action
sequence
 Evaluation
 Evaluating interpretations
 Interpreting perceptions
 Perceiving states
P e r c e i v i n g
s t a t e s
I n t e r p r e t i n g
p e r c e p t i o n s
E v a l u a t i n g
i n t e r p r e t a t i o n s
E x e c u t i o n o f
a c t i o n s e q u e n c e
S e q u e n c e o f
a c t i o n
I n t e n t i o n
t o a c t
G o a l s
T H E G A M E

21. 21
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 r c e i v i n g
s t a t e s
I n t e r p r e t i n g
p e r c e p t i o n s
E v a l u a t i n g
i n t e r p r e t a t i o n s
E x e c u t i o n o f
a c t i o n s e q u e n c e
S e q u e n c e o f
a c t i o n
I n t e n t i o n
t o a c t
G o a l s
T H E G A M E

22. 22
Seven Stages of Action
 Goals turned into intentions to act

Specific statements of what is to be done
P e r c e i v i n g
s t a t e s
I n t e r p r e t i n g
p e r c e p t i o n s
E v a l u a t i n g
i n t e r p r e t a t i o n s
E x e c u t i o n o f
a c t i o n s e q u e n c e
S e q u e n c e o f
a c t i o n
I n t e n t i o n
t o a c t
G o a l s
T H E G A M E

23. 23
Seven Stages of Action
 Intentions put into an action sequence

The order internal commands will be performed
P e r c e i v i n g
s t a t e s
I n t e r p r e t i n g
p e r c e p t i o n s
E v a l u a t i n g
i n t e r p r e t a t i o n s
E x e c u t i o n o f
a c t i o n s e q u e n c e
S e q u e n c e o f
a c t i o n
I n t e n t i o n
t o a c t
G o a l s
T H E G A M E

24. 24
Seven Stages of Action
 The action sequence is executed

The player manipulates control variables
P e r c e i v i n g
s t a t e s
I n t e r p r e t i n g
p e r c e p t i o n s
E v a l u a t i n g
i n t e r p r e t a t i o n s
E x e c u t i o n o f
a c t i o n s e q u e n c e
S e q u e n c e o f
a c t i o n
I n t e n t i o n
t o a c t
G o a l s
T H E G A M E

25. 25
Seven Stages of Action
 The state of the game is perceived

State variables are revealed via the interface
P e r c e i v i n g
s t a t e s
I n t e r p r e t i n g
p e r c e p t i o n s
E v a l u a t i n g
i n t e r p r e t a t i o n s
E x e c u t i o n o f
a c t i o n s e q u e n c e
S e q u e n c e o f
a c t i o n
I n t e n t i o n
t o a c t
G o a l s
T H E G A M E

26. 26
Seven Stages of Action
 Player interprets their perceptions

Interpretations based upon a model of the system
P e r c e i v i n g
s t a t e s
I n t e r p r e t i n g
p e r c e p t i o n s
E v a l u a t i n g
i n t e r p r e t a t i o n s
E x e c u t i o n o f
a c t i o n s e q u e n c e
S e q u e n c e o f
a c t i o n
I n t e n t i o n
t o a c t
G o a l s
T H E G A M E

27. 27
Seven Stages of Action
 Player evaluates the interpretations

Current states are compared with intentions and goals
P e r c e i v i n g
s t a t e s
I n t e r p r e t i n g
p e r c e p t i o n s
E v a l u a t i n g
i n t e r p r e t a t i o n s
E x e c u t i o n o f
a c t i o n s e q u e n c e
S e q u e n c e o f
a c t i o n
I n t e n t i o n
t o a c t
G o a l s
T H E G A M E

28. 28
Seven Stages of Action
 Donald Norman’s approximate model
 Actions not often in discrete stages
 Not all actions progress through all stages

29. 29
Seven Stages of Action
 Scales to…
 …an individual mechanic

A “primary element”
 Examples:

Move

Shoot

Talk
 …an entire game

A generalized model of interaction

30. 30
Designer and Player Models
 Systems are built from designer mental models
 Design models may only anticipate player goals
D e s i g n e r U s e r
U s e r 's
M o d e l
D e s ig n
M o d e l
S y s t e m I m a g e
S y s t e m

31. 31
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
D e s i g n e r U s e r
U s e r 's
M o d e l
D e s ig n
M o d e l
S y s t e m I m a g e
S y s t e m

32. 32
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”

33. 33
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

34. 34
Premise
 Story is the typical example of premise
 Time
 Place
 Characters
 Relationships
 Motivations
 Etc.

35. 35
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

36. 36
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

37. 37
Premise
 Goes beyond setting and tone
 Alters the players mental model
 Basis of player understanding and strategy

38. 38
Premise
 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

39. 39
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

40. 40
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

41. 41
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”

42. 42
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

43. 43
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)

44. 44
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 e s i g n e r U s e rS y s t e m
F in d s w o r d
K ill d r a g o n
R e s c u e p r in c e s s
F in d s w o r d
R e s c u e d r a g o n
K ill p r in c e s s

45. 45
Resources
 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

46. 46
Economies
 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?

47. 47
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
S i t u a t i o n R e s u l tA c t i o n

48. 48
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

49. 49
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

50. 50
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

51. 51
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

52. 52
Interface
 Interface
 Input, presentation, and feedback.
 Input
 Player to game
 Output
 Game to player

53. 53
Interface
 Contains both hardware, software, and
performance elements.
 Hardware such as game pads
 Software such as engines
 Performance such as pressing a button

54. 54
Interface
 Graphical user interface (GUI)
 A visual paradigm of control

55. 55
Interface
 Typical perspectives:
 First-person
 Over-the-shoulder (OTS)
 Overhead (top-down)
 Side
 Isometric

56. 56
Interface
 General categories of audio
 Music
 Sound effects
 Dialog

57. 57
Interface
 Music
 Powerful tool for establishing mood and theme

58. 58
Interface
 Controls
 Physical input devices
 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

59. 59
Interface
 Key map or control table
 A diagram showing control input, action,
and context

60. 60
Interface
 Control diagrams
 Show input, action, and context
A c t io n C o n t r o l C o n t e x t
L e f t a ll
R ig h t a ll
F o r w a r d a ll
B a c k w a r d a ll
S p r in t a ll
P a s s O f f e n s e
L o b O f f e n s e
S h o o t O f f e n s e
S t e a l D e f e n s e
B lo c k D e f e n s e
H it D e f e n s e

61. 61
Interface
 Front-end
 In application software

The visible portion of the application
 In games

GUI elements not displayed during play

62. 62
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
2
> n e e d b a c k u p !!!
> N o
> . . .

63. 63
Interface
 Mapping
 An understood relationship between two things

Especially the relationship of a model to its subject

Examples

64. 64
HCI and Cognitive
Ergonomics
 HCI – Human-Computer Interaction
 Study of…

Communication between users and computers

How people design, build, and use interfaces

Better support for cooperative work
 Cognitive Ergonomics
 Analyzes the cognitive representations and
processes involved with performing tasks

65. 65
Design of Everyday Things
 Norman’s five principles of design
 Visibility

Making the parts visible
 Mappings

Understandable relationships between controls and
actions
 Affordances

The perceived uses of an object
 Constraints

Prevent the user from doing things they shouldn’t
 Feedback

Reporting what has been done and accomplished

66. 66
Systems
 System
 A set of interrelated components

Their function and relationships form a whole
 Architecture
 The particular arrangement of system elements
 Game systems exist to enable play
mechanics
 Relationships between components
determine how the system works to produce
results

67. 67
Systems
 Objects
 Pieces of a system
 Attributes
 Properties determining what objects are
 Behaviors
 Actions the objects can perform
 Relationships
 How the behavior and attributes of objects affect
each other while the system operates

68. 68
Systems
 Two general approaches to design
 Special case

Experiences built one scene/level at a time

Anticipate states while pre-scripting events

Solved by discovering the intentions of the designer
 Systemic

General behaviors are designed

Scenes/Levels are specific configuations

Some events may still be pre-scripted

Solved by understanding the system

69. 69
Systems
 Emergent complexity
 Behaviors that cannot be predicted simply
from the rules of a system
 Emergence
 Coined by George Henry Lewes in 1873
 See: John Conway’s Game of Life

70. 70
Systems
 Dynamics
 The behavior of systems over time
 Generalizing dynamic behavior is hard
 Dynamics determined by a given
architecture

71. 71
Systems
 Cybernetics
 Study of communication, control, and regulation

72. 72
Systems
 A basic cybernetic system has:
 Sensor – detects a condition

Thermometer
 Comparator – evaluates the information

Switch
 Activator – alters the environment when triggered by the
comparator
S e n s o r
C o m p a r a t o r
A c t i v a t o r

73. 73
Systems
 Feedback
 The portion of a system’s output that is returned into the
system
 Feedback Loop
 The path taken by the feedback
L e v e l
G o a l
In f o r m a t i o n
A c t i o n
R a t e

74. 74
Systems
 Positive feedback
 Leads to runaway behavior
 Difficult to make use of
 Negative feedback
 Leads to goal seeking behaviors
 Most common form in systems
P o s i t i v e F e e d b a c k N e g a t i v e F e e d b a c k
g o a l

75. 75
Systems
 Negative feedback
 Stabilizes the game
 Forgives the loser
 Prolongs the game
 Magnifies late successes
 Positive feedback
 Destabilizes the game
 Rewards the winner
 Can end the game
 Magnifies early
successes
 Marc Leblanc

76. 76
Systems
 System Dynamics
 Created by Jay Forrester 1956, MIT
 A discipline for modeling and simulation

Originally a tool for policy analysis
 Applicable to any system

77. 77
Constraints
 Platform
 General description of hardware and software

Personal computer – PC, Mac, etc.

Console – Game Cube, PlayStation, Xbox, etc.

Handheld – DS, Game Boy Advance, PSP, etc.

Mobile device – Cel Phones, NGage, PDA, etc.

Arcade – custom vending games (e.g. Time Crisis)

78. 78
Constraints
 Game Saves
 Save triggers
 Save-anywhere
 Save points
 Coded text saves

79. 79
Genres
 Genre – a category describing
generalities of conventions, style, and
content

80. 80
Genres
 Action
 Adventure
 Arcade
 Casual
 Education
 Fighting
 First-person shooter
 Platform
 Racing
 Rhythm
 Role-Playing (RPG)
 Simulation
 Sports
 Strategy
 Puzzle
 Traditional

81. 81
Audiences
 Target audience
 Group of expected consumers
 Demographics
 Study of relevant economic and social
statistics about a given population
 Demographic variables
 The relevant factors

82. 82
Audiences
 Market
 Demographic segmentation of consumers

Market segments
 Smaller sub-segment of the market; more tightly defined
 Demographic profile
 Typical consumer attributes in a market

83. 83
Audiences
 Heavy Users
 Those of the numeric minority of potential users responsible
for majority of sales of any product
 “80/20 rule”
 Hardcore gamer
 Game industry term for heavy video game users
 Casual gamer
 Game industry term for all other gamers

84. 84
Audiences
 Typically assumptions of the hardcore:
 Play games over long sessions
 Discuss games frequently and at length
 Knowledgeable about the industry
 Higher threshold for frustration
 Desire to modify or extend games creatively
 Have the latest game systems
 Engage in competition with themselves, the game, and
others

85. 85
Audiences
 Why We Play Games – Nicole Lazzaro
 Internal experience

Enjoyment from visceral activities
 Hard fun

Challenge of strategy and problem solving
 Easy fun

Intrigue and curiosity – exploration and adventure
 Social experience

Stimulating social faculties – competition, teamwork,
bonding, and recognition

86. 86
Iterating
 Waterfall method
 Development methodology
 Design and production are broken into phases
 Iterative development
 Practice of producing things incrementally

Refining and re-refining the product

87. 87
Iterating
 Prototypes
 Early working models of the product
 Used to test ideas and techniques
 Physical prototypes
 Non-electronic models; physical materials
 Software prototypes
 Used regularly during iterative development

88. 88
Iterating
 Software testing
 Process of verifying performance and reliability of a software
product
 Tester
 Person trained in methods of evaluation
 Bug
 Discrepancy between expected and actual behavior
 Problem/Bug report
 Description of the behavior of the discrepancy

89. 89
Iterating
 Focus test
 Testing session using play-testers
 Testers represent the target audience
 Lots of feedback at one time
 Data can be compromised by group think

90. 90
Iterating
 Tuning
 Developing solutions by adjusting systems
 Iterations are faster
 Changes are less dramatic
 Balance
 Equilibrium in a relationship

Player relationships, mechanics, systems, etc.

91. 91
Iterating
 Intransitive relationships
 Multiple elements offer weaknesses and strengths relative to
each other as a whole
 Balanced as a group
 Example: Rock-Paper-Scissors (RPS)
H e a v y
I n f a n t r y
C a v a l r yA r c h e r s

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Creativity
 Ability to create
 Ability to produce an idea, action, or
object considered new and valuable

93. 93
Creativity
 Classic approach - Graham Wallace
 Preparation

Background research and comprehension
 Incubation

Mulling things over
 Insight

Sudden illumination – Eureka!
 Evaluation

Validating revealed insights
 Elaboration

Transforming the idea into substance

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Creativity
 Brainstorming
 Generating ideas without discrimination
 Evaluation after elaboration
 Can be unfocused

95. 95
Creativity
 Six Thinking Hats
 White Hat – neutral and objective
 Red Hat – intuition, gut reaction
 Black Hat – gloomy, naysayer
 Yellow Hat – Pollyannaish, optimistic
 Green Hat – growth and creativity
 Blue Hat – process and control
 Symbolize perspective worn by people involved in the
creative endeavor
 Edward de Bono

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Inspiration
 Board games
 Spatial relationships
 Card games
 Resource management
 Paper RPGs
 Dynamic narratives
 Books
 Fantasy and agency
 Sports
 Team competition
 Film
 Continuity techniques
 Television
 Serialized stories
 Music
 Temporal systems
 Martial arts
 Discipline in action
 Children
 Invention

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Communication
 Documentation
 Methods vary widely
 Written, descriptive model of the game

Depth varies according to the needs of the game

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Communication
 Treatment
 A brief, general description of the game and the
fundamental concepts
 May include:

Concept statement

Goals and objectives

Core mechanics and systems

Competitive analysis

Licensing and IP information

Target platform and audience

Scope

Key features

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Communication
 Other document types may include:
 Preliminary design document
 Initial Design Document
 Revised Design Document
 General Design Document
 Expanded Design Document
 Technical Design Document
 Final Design Document

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Communication
 Flowcharts
 A typical technique for diagramming steps in a
process
 Most developers are familiar
S t a r t / E n d
P r o c e s s /
A c t i o n
D e c i s i o n
Y / N D e l a y

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Communication
S t a r t
W a n d e r i n g
C i t y
S e a r c h f o r
Q u e s tQ u e s t
Q u e s t D e t a il sA c c e p t
G a t h e r P C A ll ie s E m b a r k /S p l it G o t o
W il d e r n e s s
C i ty
N o
Y e s
Y e s
N o
R e c r u i ts
R e c r u it
E q u i p
G e a r
G a th e r
S e e k A id
A r t if a c t s
A ss i s ta n c e
R e g r o u p
E n c o u n t e r

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Communication
 Associative diagram
 Drawing that helps manage and organize information visually
 Mind Map
 A style of associative diagram
 Key words and figures are placed on branches
w e a p o n
f i g h t i n g
r a n g e

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Psychology
 Working Memory
 Holds roughly 7 ± 2 items at one time while
other cognitive operations on them

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Psychology
 Attention
 Method of enhancing perceptions relative
to other stimuli in the same environment
 How we focus on important things
 Limited capacity

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Psychology
 Classical conditioning
 Reaction to stimulus is conditioned by pairing with another
stimulus that elicits the desired response naturally
C o n d i t i o n i n g A f t e r c o n d i t i o n i n g
B e f o r e c o n d i t i o n i n g

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Psychology
 Unconditioned stimulus – Meat
 Unconditioned response – Salivation over meat
 Conditioned stimulus – Tone
 Conditioned response – Salivation over tone
C o n d i t i o n i n g A f t e r c o n d i t i o n i n g
B e f o r e c o n d i t i o n i n g

107. 107
Psychology
 Operant conditioning
 Learning by encouraging or discouraging
 Operant
 A response; the action in question

Example: pressing a button
 Reinforcement contingency
 Consistent relationship between the
operant and a result in the environment

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Psychology
 Reinforcers
 Increase the probability an action will be repeated
 Positive reinforcement
 Positive stimulus that reinforces the behavior

Ex. Use umbrella and be dry
 Negative reinforcement
 The removal or prevention of a negative stimulus

Ex. Use umbrella and keep from getting wet
 Punishment
 Reduces the likelihood of a behavior with a stimulus

Ex. Being burned by a hot stove