Computer Game Development By Jijun Tang

Announcements groups.google.com/group/csce552 Groups must be formed this week, please give me your group members’ names after the class or later Game design should be started, we will have our first presentation on Feb 3rd

Ox Game Engine for XNA

JigLibX for Physics

What is a game A game is a form of art in which participants, called players, make decisions in order to manage resources through game tokens in the pursuit of a goal. (Greg Costikyan) A game is a system in which players engage in an artificial conflict, defined by rules, that results in a quantifiable outcome. (Salen and Zimmerman)

Game Design Early game design practices resemble the authoring of folk tales:  The game elements and rules evolve over time by the effort of countless nameless “ designers ” Game design has developed towards systematic practices, games designed on purpose Craft vs. Design  Characteristics of a craft product: combination of the methods and materials available as well as the situations in which the product has been used over a longer period of time  Characteristics of a designed product: the result of a trying to reach a design goal by using methods and materials available From The Book’s slides

Factors (Crawford) Crawford: The Art of Computer Game Design (1984) Identifies four common factors between all games:  Representation  Interaction  Conflict  Safety

Features (Costikyan) “ I Have No Words & I Must Design ” (1994) Identifies design choices that have to be made when games are designed And the main features necessary for games:  Decision making  Goals  Opposition  Managing resources  Game tokens  Information

MDA (Hunicke, LeBlanc, Zubek ) Mechanics, Dynamics, and Aesthetics Three main components:  Mechanics that describe the parts of a game at the level of data representation and algorithms  Dynamics that describe the run-time behavior of the game  Aesthetics that describe desirable emotional responses evoked in the player during gameplay Sensation, game as sensory pleasure Fantasy, game as make-believe Narrative, game as drama Challenge, game as obstacle course Fellowship, game as social framework Discovery, game as uncharted territory Expression, game as self-discovery Submission, game as pastime Provide a framework to span game design, development, game criticism and research

400 Projects (Rules) The rules consist of five parts  An imperative statement of the rule  A description of the domain of the rule  Rules which take precedence over the rule  Rules that the rule takes precedence over  A description of examples and counter- examples The rules are meant to be tools which can be used in different phases of the design process

Areas and Challeges (Adams, Rollings) Three different areas  Core mechanics  Interactivity  Storytelling  Narrative Categorizing different types of challenges:  Pure challanges (logic and inference, lateral- thinking, memory, intelligence-based, knowledge-based, pattern-recognition, etc.)  Applied challenges (races, puzzles, exploration, conflict, economies and conceptual challenges)

Basic Elements (Game Design Workshop) Identify eight basic formal elements:  Players  Objective  Procedures  Rules  Resources  Conflicts  Boundaries  Outcomes The design method is to use the formal elements to describe the current design and make sure that all aspects of a game design are taken into consideration

CSCE 552 Spring 2008 Understanding Fun

What is Fun? Game is all about fun Dictionary: Enjoyment, a source of amusement It is important to consider underlying reasons Funativity – thinking about fun in terms of measurable cause and effect

Why fun? It ’ s deep in our evolution root, and we must look to our ancestors (200 yrs of tech advancement haven ’ t changed our instinct) Cats, dogs, etc play to learn basic survival skills (physical and social) Games are organized play Human entertainment is also at its heart about learning how to survive Social rules are also critical to us

Surviving Life is all either work, rest, or fun To survive, we must work  Our ancestors were those who survive  The survive skills are passed down Who is more likely to survive?

People working too hard?

People resting too much?

We must play to gain skills

Learning is fun Fun is about practicing or learning new survival skills in a relatively safe setting People who didn ’ t enjoy that practice were less likely to survive to become our ancestors

Hunting and Gathering Basic skills are hunting and gathering Current popular games reflect this It ’ s a good start point to design games Shooters, wargames = hunting Powerups, resources = gathering Sims, MMO = social, tribal interaction

Gathering and hunting

Natural Funativity Theory All funs are derived from practicing survival and social skills  Key skills relate to early human context  Often in modern guise: play chess, football, dance, etc Three overlapping categories  Physical  Social  Mental

Physical Fun Sports  Enhance our strength, stamina, coordination skills  Winning is also a mental fun Exploration  Knowledge of surrounding areas  Explore unknown Hand/eye coordination and tool use are often parts of fun activities – crafts Physical aspect to gathering “ stuff ”

Wii Sports

Social Fun Storytelling is a social activity  First virtual reality  Learn important lessons from others Gossip, sharing info Flirting Showing off

Social funs

Mental Fun Humans have large brains Abstract reasoning practice Pattern matching and generation  Music  Art  Puzzles Gathering also has mental aspect, categorizing and identifying patterns Gambling

Casino/Online Gambling

Multipurpose Fun Many fun activities have physical, social and mental aspects in combination Games that mix these aspects tend to be very popular Incorporate ways to practice these skills to increase the popularity of games

Game 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

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

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

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

Seven Stages of Action Intentions put into an action sequence The order internal commands will be performed

Seven Stages of Action The action sequence is executed The player manipulates control variables

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

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

Seven Stages of Action Player evaluates the interpretations Current states are compared with intentions and goals

Designer and Player Models Systems are built from designer mental models Designer models may only anticipate player goals

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

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

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

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  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