Game Design: Theory & Practice- P20 pptx

CTF: Typically refers to Capture the Flag multi-player games, though it may also refer to Valve Software’s Classic Team Fortress game.. Cut-Scene: A non-interactive portion of a game typ

Beta: The state games reach after passing through Alpha, and the last step before agame is published or otherwise released to the public In Beta, changes made to a gameare supposed to be strictly limited to bug fixes Some developers define Beta to be

when they first have what they consider to be a release candidate See also Alpha and Release Candidate.

Bible: Used in the gaming industry to refer to various reference materials used during

a game’s development See Art Bible and Story Bible.

Boss Monster: An enemy in a game, though not necessarily a “monster” per se,which is much larger or simply more difficult to defeat than the other opponents in thegame Typically boss monsters are placed at the end of levels and provide a climax forthat level’s gameplay

’Bot: Short for “robot,” this refers to artificial intelligence agents that are designed toappear to play similarly to humans, typically designed to work in first-person shooter

death-match games Quake III Arena and Unreal Tournament both feature ’bots as the

player’s only opposition in the single-player game

BSP: Short for Binary Space Partition A method for storing and rendering 3D spacewhich involves dividing the world into a tree of space partitions, most famously used in

id Software’s games Doom and Quake.

Builder Games: One term used to describe games in which the player is responsiblefor building lasting structures in the game-world In a sense, in builder games, the play-

ers are responsible for the level design Examples of this type of game are SimCity, Civilization, RollerCoaster Tycoon, and The Sims.

Burn Rate: The amount of money a company, typically a developer, spends in amonth to keep itself in business This typically includes all of the employees’ salaries,rent, utilities, and other persistent expenses Sometimes publishers will try to fund adeveloper only to the extent of its burn rate, so that the developer does not have anyspare cash and remains forever beholden to the publisher

Candidate: See Release Candidate.

Capture the Flag: A game involving two teams, both of which have a flag The flag

is kept at a specific location and possibly guarded, while the players on both teams try

to grab the other team’s flag through stealth or brute force In computer games, this isoften a game variant offered in first-person shooter multi-player cooperative games,

such as Quake or Unreal.

Choke-Point: A point in a game past which a player can progress only by passingthrough a particular area, completing a particular puzzle, or defeating a particular mon-ster Often the areas preceding and following a choke-point allow the player morefreedom of play, while the choke-point presents a task the player absolutely mustaccomplish before proceeding

Team-Fly®

Classic Arcade Game: Does not necessarily mean a game that is a classic, but anygame which was released during the early period of arcade games or which exhibits thetraits typical of those games Classic arcade games include simple, single-screen-player

games such as Space Invaders, Centipede, Robotron 2084, or Pac-Man Classic arcade game is defined more fully in Chapter 4 See also Arcade Game.

Code: When used in reference to games, code is the lines of text that programmersenter into the computer and which the computer then compiles into the functionalgame A talented programmer is sometimes referred to as a code-jockey

Color: Beyond the obvious definition, in terms of game design this may also refer to

the specific content and setting of a game Monopoly, for instance, includes the street

names of Atlantic City and a depression era real-estate mogul theme as a means of viding color Color is separate from the gameplay itself

pro-Concept Document: Also known as a pitch document This is a short document thatincludes text and concept sketches and that is used to initially sell the idea of a project

to a publisher or other financier A concept document gives the reader an idea of whatthe game will involve without including sufficient detail to actually develop the game

If accepted, the concept document is usually expanded into the design document

Concept Sketch: A sketch of a particular game art asset which is used to show one what the art will look like, approximately, before that graphic or model is actuallycreated May also be a sketch of a scene from the game as it will appear once the game

road in The Wizard of Oz.

CRPG: A computer version of a role-playing game See also Role-Playing Game.

CTF: Typically refers to Capture the Flag multi-player games, though it may also

refer to Valve Software’s Classic Team Fortress game See Capture the Flag.

Cut-Scene: A non-interactive portion of a game typically used to communicate to theplayer information about the game’s story line, sometimes involving pre-rendered orlive action full-motion video, other times using the game’s real-time graphics engine.Cut-scenes often come between levels in a game, and are sometimes used as rewardsfor the player having finished a particularly challenging portion of the game

Death March: When a development team, particularly the programmers, worksevery waking moment on a project for a long period of time, typically trying to make anunachievable deadline of some sort Often the death march is entered into thinking itwill be over soon enough, but it then drags on long beyond what anyone thoughtpossible

Death-Match: A multi-player game in which the players’ only goals are to kill each

other Usually refers to games of that sort in first-person shooters such as Doom, Unreal, or Duke Nukem 3D.

Design Document: The textual reference used in developing a game which attempts

to describe in detail every important aspect of the game’s design Sometimes referred to

as the Functional Specification Described more completely in Chapter 17, “The DesignDocument.”

DM: Depending on context, see Dungeon Master or Death-Match.

Dungeon Master: The term for the Game Master used in conjunction with Dungeons

& Dragons games See Game Master.

Engine: The core code that handles the most basic functionality of the game, but notincluding the code which governs specific gameplay functionality Sometimes theengine is split up into the rendering engine, the sound engine, the behavior engine, and

so forth Each of these components can be considered to be part of the game’s engine as

a whole Engines are typically more general than a particular game, which allows them

to be reused for multiple different projects However, some developers use the termEngine to refer to the entirety of a game’s source code For example, id Software has

licensed their Quake engine for use in a broad range of games, from Half-Life to dier of Fortune to Heavy Metal: FAKK 2.

Sol-Finite State Machine: See State-Based AI.

First-Person Shooter: The type of game exemplified by Doom, Half-Life, Unreal, Marathon, Quake, and Duke Nukem 3D In first-person shooters, the player’s perspec-

tive of the world is from the first person and her objective is to shoot everything insight, though some first-person shooters offer some subtle variations on this goal

Flight Simulator: Often shortened to flight sim, this is a type of game whichattempts to model the flight of a real-world aircraft The amount of realism involvedvaries from game to game; some games are extremely realistic and difficult, while oth-

ers prevent the player from crashing entirely Examples include Microsoft Flight Simulator, F-15 Strike Eagle, Flight Unlimited, and Hellcats Over the Pacific.

FMV: See Full-Motion Video.

Focus: A brief, three- to five-sentence description of the most important conceptsguiding a game’s development Described in detail in Chapter 5, “Focus.”

FPS: Depending on the context, this may refer to the first-person shooter genre of

games or to the frames per second that the game’s engine is currently rendering See

First-Person Shooter

FSM: Stands for finite state machine See State-Based AI.

Full-Motion Video: Any non-real-time graphics in a game which are displayedquickly in a sequential order to create a movie-like effect Full-motion video can be of

live actors, computer-generated environments, or a combination of the two.

Functional Specification: The sister document to the Technical Specification, in that

it describes how the game will function from the user’s perspective, as opposed to howthe programmer will implement that functionality In game development, typically

referred to as the Design Document See also Design Document.

Fuzzy Logic: A type of AI that introduces some degree of randomness into the sion making process This means that, given the exact same inputs, an AI agent willmake different decisions based on chance

deci-Game: The Oxford Universal Dictionary includes a number of definitions for

“game.” The definition we are most interested in for this book reads as follows: “Adiversion of the nature of a contest, played according to rules, and decided by superiorskill, strength, or good fortune.” To rephrase, a game presents an entertaining challenge

to the player or players, a challenge which the player or players can understand andmay be able to succeed at using their wits, dexterity, luck, or some combination thereof

To expand, in order for that challenge to be meaningful, the player must be presentedwith a number of interesting choices for how to succeed at the game, and those choicesmust be non-trivial And in order for the challenge to be truly meaningful, the game

must define the criterion for success This excludes “software toys” such as SimCity

from being games Of course, one could write an entire book about the nature of agame, but this is not that book

Game Design: The game design establishes the shape and form of the gameplay in agame The game design may be communicated through a design document, or it may

only exist in the head of the implementors of the game See also Gameplay.

Game Designer: The game designer is the person on a project who is responsible for

establishing the form of the gameplay through the game design See also Gameplay and

Game Design

Game Engine: See Engine.

Game Flow: The chain of events that make up the playing of a given game A gamecan be said to flow between its action, exploration, puzzle-solving, and storytellingcomponents The proportional amount of time spent in each of these components andthe pace at which the game takes place contributes to its overall flow

Game Master: In a pen and paper role-playing game, the game master is the playerwho governs the actions of all of the other players in the game-world The game masteroften has also dreamt up the adventures that the players are going on, and continues todynamically create this story as the players navigate through it

Game Mechanic: A specific way in which a part of the gameplay is implemented

For instance, the mechanic for doing an attack-jump in Crash Bandicoot is to hold

down the “down” or “crouch” button while in mid-jump The mechanic for sending a

unit to a new location in WarCraft is to click on the unit in question with the left mouse

button, move the pointer to the desired position on the map, and then to click there withthe right mouse button The gameplay as a whole is made up of a number of differentgame mechanics combined together.

Gameplay: The gameplay is the component that distinguishes games from all otherartistic mediums The gameplay defines how the player is able to interact with thegame-world and how that game-world will react to his actions One could consider thegameplay to be the degree and nature of a game’s interactivity Of course many differ-ent people have different definitions for gameplay, but as far as this book is concerned,gameplay does not include the game’s story, graphics, sound, or music This is easy tounderstand if one recalls that gameplay is what separates games from other artisticmediums; each of these components is found in literature, film, or theater Gameplayalso does not include the code used to make the game run, the game’s engine, thoughthat engine does necessarily implement the gameplay The gameplay, however, could beimplemented using a completely different engine while remaining identical

Game-World: This is the space in which a game takes place In a board game such

as The Settlers of Catan, the game-world is represented by the board the game takes

place on For a sports game, the game-world is the real-world but is limited to theextent of the field the game is played on For a role-playing game, the game-world ismaintained within the imaginations of the game master and the players For a computergame, this is a “virtual” space which is stored in the computer’s memory and which theplayers can view via the computer screen The actions the player makes in a game arelimited to the game-world, as are the reactions of either the game itself or the otherplayers

GM: Depending on the context, see Gold Master or Game Master.

Going Gold: The time when a team completes a game and is thereby able to create

the Gold Master which is sent to the duplicators See also Gold Master.

Gold Candidate: See Release Candidate.

Gold Master: The version of the game, typically recorded onto gold CDs, which isgoing to be used by the duplicator to create copies of the actual shipping game In otherwords, the final version of the game

Graphical User Interface: This is any communications method the player has ofinteracting with the computer that is primarily graphical in nature For instance, theMacintosh has always had a graphical user interface, as opposed to the text-orientedone available in MS-DOS or UNIX Games use GUIs for starting up new games, load-ing saved games, and choosing other options from the main menu, but also for

communicating information to the player not readily apparent from their view of thegame-world: the player character’s health, currently equipped weapon, amount ofammo, number of lives, score, and so forth

GUI: See Graphical User Interface.

Heads Up Display: A type of graphical user interface which is overlaid on top of theplayer’s game-world view This may include the player character’s health, a mini-map

of the area, or radar of some sort, and typically communicates vital information towhich the player must always have easy access Heads up displays take their name fromthe displays used by jet fighter pilots, which constantly convey crucial flying informa-

tion to those pilots while they are navigating the plane See also Graphical User

Interface

High Concept: An idea for a game which attempts to merge disparate types ofgameplay or setting into one game, without regard to whether those different ideas willwork well together An example might be making a first-person shooter which is also aracing game, or a wargame which includes a golf simulator Usually synonymous with

“bad concept.”

HUD: See Heads Up Display.

IF: See Interactive Fiction.

IK: See Inverse Kinematics.

Input/Output: Often shortened to I/O, this refers to the systems a computer uses toallow the player to input information (typically a keyboard and a mouse) in combina-tion with how it communicates information back out to the user (typically the monitor)

In terms of computer games, the I/O refers to the controls with which the player ulates the game and the way the game then communicates to the player the currentnature of the game-world

manip-Interactive: An interaction is when two systems, be they a human and a human, ahuman and a computer, or a computer and a computer, are mutually active in a givenprocess For instance, a television show is not interactive, since only the television out-puts data and completely ignores whatever the user/audience does A conversationbetween two people is interactive, however, since both parties listen to what the otherhas to say and will then say something related or in response to that As another exam-ple, a strict lecture is not interactive since the lecturer reads a prepared speech withoutany input from the audience A discussion group, however, is interactive, since the pro-fessor or leader of the discussion will answer the students’ questions and listen to andevaluate their ideas Games are interactive since they allow both the player and thecomputer to determine the shape of that particular game Computer games are not beingespecially interactive when they play long cut-scenes over which the player has nocontrol

Interactive Fiction: A term originally coined by Infocom, which is an alternatename for text adventures Some people use interactive fiction to describe any gameswhich use text to describe scenes and include a text parser, even if graphics are also

included See also Text Adventure.

Interactive Movie: A term coined by those working in games who wish to call theirprofession something more glamorous than what it is, similarly to how the comic bookindustry sometimes attempts to call some of its longer and more sophisticated works

“graphic novels.” Typically, interactive movies involve more and longer cut-scenes thanyour average game Unfortunately, the makers of so-called “interactive movies” typi-cally add more movie than they do interactivity, resulting in works which are almostalways not very good movies and lack the interactivity to be good games

Inverse Kinematics: An animation technique whereby a joint in a character’s ton is moved to a desired location and the joints that depend on or are influenced bythat joint are automatically moved to the correct location For example, if animating ahumanoid, the hand could be moved toward a door handle and the elbow and shoulder

skele-would automatically move to reasonable positions See also Skeletal Animation.

I/O: See Input/Output.

Isometric: Isometric is defined to mean “equality of measure,” particularly in ence to drawing objects If one were isometrically drawing a cube from a distance withone of the points of the cube pointing directly toward the viewer, the lines of the cubewould all be of the same length and would not use any foreshortening Games such as

refer-Civilization II, SimCity 2000, SimCity 3000, and StarCraft are drawn isometrically.

This allows a game to be drawn from a somewhat 3D overhead view which can then bescrolled around in all directions, without actually needing to involve a 3D renderingengine The perspective on the world is technically wrong, but players do not seem tomind Also referred to as a “three-quarters” view of the game world

LAN: An acronym for a Local Area Network These networks typically consist of asmall number of computers in a specific area networked to each other but not necessar-ily to the Internet or other networks

LAN Party: Held when a bunch of friends get together, bring their computers to onecentral location, and play multi-player games over them Typically the fast “Ping” timesallow players to have much faster and more lag-free games than are available over theInternet or other long-distance networks

Linear: When the only one way to get from point A to point B is via the line segmentwhich connects them, we say that the movement is linear Linear implies a lack ofchoice outside of a single dimension: forward or backward In gaming, a linear game isone that does not give the player much choice in what he does For some games, linearmay mean no choice at all, since backward is often not even an option

Lone Wolf: Term used to describe game developers who do practically everythingthemselves in the development of a game: the design, programming, art, sound, andwriting At the very least, a lone wolf developer must do all of the game’s design andprogramming herself A lone wolf does not typically develop commercially releasedsoftware any more, though there are exceptions For example, Chris Sawyer designed

and programmed all of RollerCoaster Tycoon by himself, with a contractor completing

the art to his specifications Though he did not do the art himself, Sawyer can still bedescribed as a lone wolf developer

Massively Multi-Player: Strictly, a multi-player game involving a very large number

of people playing it at once, at least 100 or more Typically such games are also

persis-tent and played over the Internet Ultima Online and Ever Quest are examples of massively multi-player games See also Multi-Player and Persistent.

Media: Go out and buy Marshall McLuhan’s Understanding Media Read it Come

back only when you fully understand it

Metagame: According to Richard Garfield, creator of Magic: The Gathering, the

metagame is “how a game interfaces with life.” This means what the player takes toand brings away from a particular playing of a game and how that impacts his subse-quent playings of that game This is particularly applicable to multi-player games Take,

for example, a game of Quake III Arena on the Internet If one player is known to play

unethically through camping and other undesirable tactics, players will be likely tomake a special effort to eliminate him in subsequent games This means that the playermay end up losing subsequent games because of his behavior in previous games Thisinteraction between the players from game to game is not part of the playing of thegame itself, but is part of the metagame that the playing creates For another example,

in Magic: The Gathering the time a player spends preparing his deck before a game,

though not part of the game itself, is part of the metagame

Milestones: A term often used in contracts between publishers and developers Amilestone is an agreement of how much work on a project will be done at a specificdate, with the publisher only paying the developer when that milestone (usually in theform of a current build of the game) is delivered to the publisher

Mod: Short for “modification,” mods are user-created add-ons or changes to an ing game Mods were popularized by id Software’s open-architecture policy which

exist-allowed players to make their own levels for Doom Beyond levels, mods also often

include new AI, new weapons, new art, or some combination of all three, potentiallycreating a radically altered gameplay experience from what was found in the originalgame

MUD: Stands for Multi User Dungeon MUDs resemble a text adventure with heavyRPG elements in their central play mechanics, with the important difference being thatthey take place in persistent, massively multi-player worlds MUDs were set up and run

by college students starting in the 1980s Players of the games, when they reached ahigh enough experience level or rank, would become the creators of the games’ contentfor other, more inexperienced players to explore The primary interest many playershave in MUDs is the social component, preferring to chat with people they have never

seen before to going on Dungeons & Dragons style adventures In many ways, Ultima Online is a carefully regulated graphical MUD Another popular variant are MOOs,

which stands for MUD, Object Oriented In terms of game design, MOOs and MUDsare identical; only the way they are programmed and set up is different.

Multi-Player: A game that involves more than one player Today, this typically alsomeans “networked multi-player” where each player has his own computer and com-petes with the other players over a network, such as the Internet

Non-Linear: Obviously, the opposite of linear In terms of gaming, this means thatthe player is not locked into achieving different goals in a specific order or in achievingall of the goals she is presented with Instead, the player is able to move through thegame in a variety of paths and can be successful in a variety of ways Non-linearity

leaves the player with more choice to play the game her own way See also Linear and

On a Rail.

Non-Player Character: Any character in a computer game which is not controlled

by the player Typically this refers to game-world characters who are not hostile to theplayer, such as townspeople in an RPG

NPC: See Non-Player Character.

NURBS: Stands for non-uniform rational B-splines A 3D graphics technique for ating curved surfaces, a detailed explanation of which should be sought out in a 3Dgraphics programming book

cre-On a Rail or cre-On Rails: A game is said to be on a rail when a player is forced tomove through the game in a very specific, carefully controlled way, as if he werelocked onto a rail that ran through the game Games which are said to be “on a rail” or

“on rails” are very linear games A specific type of game called a “rail shooter” is onrails to such an extent that the flight path of the player’s vehicle is completely predeter-

mined, and the player is only able to shoot at targets as they pass by Rebel Assault is an example of a rail shooter See also Linear.

180 Degree Rule: A film technique for cutting a scene that says that the camera mustalways stay on one side of a line that extends between the two centers of attention in theframe If the camera never rotates anywhere outside of those 180 degrees, the audiencewill not become confused by the scene’s cuts from character to character

Parser: In gaming, often refers to the input method used by text adventures A parsertakes natural language words or sentences the player enters and translates them intocommands that the game logic can understand Parsers can become quite sophisticatedwhile still failing to understand many of the sentences that players attempt to use ascommands Natural language processing is a major field of AI research, one that is stillfar from perfect, so it is no wonder that parsers have as much trouble as they do Amore modern usage of the term parser is in reference to the interpreter for a game’s

scripting language See also Text Adventure.

Pathfinding: This is the portion of the AI code which allows an agent to figure outhow to get from one location to another in the game-world Ideally, pathfinding allows

the AI agent to avoid getting stuck on obstacles or other agents, yet pathfinding inmany games is less than perfect There are various algorithms, such as A*, that can beused for pathfinding which may have different results in terms of efficiency and thequality of the paths generated, though that is a topic better explored in a book about

programming See also A*.

PC: May refer either to a game’s player character or to the Intel-based personal

com-puter originally popularized by IBM and powered by MS-DOS Also see Player

Character.

Persistent: A persistent game is one which continues running and maintaining thestate of the game-world regardless of whether a particular player is actively playing it

or not Often persistent games are also massively multi-player, and vice versa MUDs

were one of the first persistent games, while commercial products such as Ultima Online and Ever Quest have made persistent games quite popular to mainstream gamers See also MUDs.

Pitch Document: See Concept Document.

Place-Holder: Typically refers to sounds or art used in a game while it is in ment but which the development team plans to replace before the game is released tothe public

develop-Platform: Often used to describe the different systems a game can be developed for.Popular gaming platforms past and present include the Apple II, Atari 800, Commodore

64, IBM PC, Commodore Amiga, Macintosh, Atari 2600, Nintendo Entertainment tem, Sega Genesis, and the Sony PlayStation

Sys-Player Character: This is the character the player controls in the game, such as

Mario in Super Mario 64, Lara Croft in Tomb Raider, or the space marine in Doom This term is a holdover from pencil and paper RPGs such as Dungeons & Dragons.

Player Surrogate: See Surrogate.

Playtesting: A term referring to the process of testing the gameplay of the game tosee how well it plays Playtesting is different from bug fixing or quality assurance ingeneral since playtesting focuses on the performance of gameplay itself instead of gen-eral bug fixing See Chapter 23, “Playtesting.”

Port/Porting: The process of converting a game from one gaming platform toanother, such as from the PC to the Macintosh, or from the Sony PlayStation to theNintendo 64 Typically, games which are ported are completed on one system first, andonly then brought over to the other system

PR: See Public Relations.

Pre-Rendered: 3D graphics which are rendered into 2D sprites or images before the

player plays the game Myst features pre-rendered 3D graphics, while Unreal features real-time 3D graphics See also Real-Time 3D.

Proposal: See Concept Document.

PSX: An abbreviation for Sony’s PlayStation console Actually based on an earlyname for the system, the PlayStation X Nonetheless, the abbreviation stuck However,Sony does not like you calling their newer system the PSX2

Public Relations: A wing of the marketing department whose primary job is to hype

a company’s upcoming games in the press by readying press releases, screenshots, andother information They also can be quite helpful in granting permission to usescreenshots in books such as this one

QA: See Quality Assurance.

Quality Assurance: This is the process of testing a game to make sure that it isbug-free and plays reasonably well The quality assurance cycle or period is the timewhen a nearly complete project is extensively tested just prior to release In large com-panies, the quality assurance department or team are the people who are going toperform that testing

Rail, On a: See On a Rail.

Real-Time: Anything that is computed or rendered for the player while he waits,such as graphics and pathfinding This differentiates something from being pre-computed before the actual gameplay is taking place Can also differentiate a game

from being turn-based See also Turn-Based.

Real-Time Strategy: A currently popular genre of games, including such titles as

Command & Conquer, WarCraft, Total Annihilation, and Myth: The Fallen Lords This

term is typically emphasized to differentiate these RTS games from turn-based strategy

games such as Civilization, X-Com: UFO Defense, and Alpha Centauri.

Real-Time 3D: Describes 3D graphics which are rendered while the player is ing at them, so that as the player moves around the world, many different views of

look-objects and configurations of the game-world can be generated on the fly Unreal uses real-time 3D graphics while Myst uses pre-rendered 3D graphics See also

Pre-Rendered.

Release Candidate: A build of the game which the development team believes may

be the one that can be shipped A release candidate is generally tested for at least a fewdays, optimally a week or two, to determine if it is bug-free enough to be acceptable tothe publisher It is not uncommon for a particular product to go through five or morerelease candidates

Role-Playing Game: Games based on the type of gameplay established by pencil

and paper role-playing games such as Dungeons & Dragons Those original

non-computer-games were so titled because in them players took on the roles of ters of their own creation and guided them through a fantasy world Much of thegameplay in RPGs depends on the players role-playing these characters who often hadpersonalities different from their own Ironically, most computer role-playing games

Team-Fly®

often contain very little of the role-playing aspect of traditional RPGs, instead choosing

to concentrate on the combat mechanics and fantasy setting

RPG: See Role-Playing Game.

RT3D: See Real-Time 3D.

RTS: See Real-Time Strategy.

Scripted: In terms of a game, scripted typically refers to AI behaviors that areplanned in advance to allow the AI agents to look clever in specific situations in a level

Scripted events play the same way every time a player plays a level Half-Life used

scripted events to produce very impressive gameplay effects that gave the illusion of avery smart AI system

Sim: Short for simulator or simulation See Simulation.

Simulation: In a game described as a simulation, the primary goal of the game’sdesigner is to model a real-life system accurately and realistically, instead of simplymaking the game as fun as possible This system could be anything, such as an aircraft

of some kind, a race car, or a city

Simulator: See Simulation.

Skeletal Animation: An alternative to vertex deformation for 3D animations With askeletal animation system, the game keeps track of an animating character’s skeleton.The animation then controls this skeleton, moving the animating character’s mesh tomatch the skeleton properly A skeletal animation system has the advantage of causinganimations to take up much less space than when they are animated using a techniquesuch as vertex deformation, as well as often leading to superior looking animations.Furthermore, the skeleton can be controlled procedurally for inverse kinematics effects

of various types See also Vertex Deformation and Inverse Kinematics.

Skin: In gaming, skin refers to the texture set being used on a 3D player character in

a game like Quake III Arena or Unreal Tournament Players will get to choose what

skin they play the game with either from the default collection that comes with thegame, or by making their own and importing it into the game This has recently become

popular outside of the realm of first-person shooters in The Sims.

SKU: Stands for stock keeping unit or shelf keeping unit It is the unique numberassociated with every bar code and used by stores to track their inventory Each uniqueversion of a game is sometimes referred to as a different SKU If one game ships for anumber of different platforms, say Macintosh and PC, then each version is a separate

SKU Similarly, Thief and Thief Gold are two different SKUs, though they are

practi-cally the same game

Software Toy: A term coined by Will Wright of Maxis to describe that company’s

first product, SimCity A software toy is quite similar to a game, except that it defines

no criterion for success The player is just left to play with the game as she wishes out ever “winning” or “losing.” Yet a player may make a software toy into a game by

with-defining her own personal conditions for success See also Game.

State-Based AI: A type of AI which uses states for each of its agents States includeactions such as idle, walking, attacking, and so forth The AI then switches the agentfrom one state to another depending on the conditions of the game-world May also bereferred to as a finite state machine or FSM

State Machine: See State-Based AI.

Story Bible: A document that contains all the information available about the storyelements of the game-world Story bibles can be quite large, especially when working

with properties with established histories, such as the Star Trek or Ultima universes.

These documents are usually used as reference works for the developers during thegame’s creation Described in detail in Chapter 15, “Game Development

Documentation.”

Surrogate: A term used to describe the entity that the player controls in the game,

also known as the player character or the player’s avatar See also Avatar and Player Character.

TDD: See Technical Design Document.

Technical Design Document: This document takes the gameplay as described in theDesign Document and explains how that gameplay will be implemented in more techni-cal, code-centered terms As a result, this document is often used primarily by theprogramming team Described in detail in Chapter 15, “Game DevelopmentDocumentation.”

Technical Specification: Another name for the Technical Design Document See

Tech-nical Design Document.

Text Adventure: Text adventures are devoid of graphics and describe the world to the player exclusively through text Players are then able to interact with thegame-world by typing in natural language sentences in the imperative form stating whatthey want their character to do next The form was made extremely popular by Infocom

game-in the early 1980s See also Interactive Fiction.

Three-Quarters View: Typically refers to games that have an isometric view point.This view can be in any rendering system with an overhead view of the ground where

the camera is oriented at a 45-degree angle from the plane of the ground See also Isometric.

Turn-Based: Any game where the computer waits for the player to act before

pro-ceeding with its own actions Civilization, for instance, is a turn-based strategy game, while WarCraft is a real-time strategy game For some non-computer game examples,

chess is a turn-based game while football (soccer) is real-time American football is abizarre hybrid of real-time and turn-based gameplay

Turn-Based Strategy: See Turn-Based.

Vertex Deformation: A 3D animation system where the individual vertices of amodel are moved one by one to new positions for each frame of the animation This isthe simplest 3D animation method to code for, but has many disadvantages over a skel-

etal animation system Sometimes also called key-frame animation Also see Skeletal Animation.

Virtual Reality: Technically, virtual reality, or VR, refers to advanced

world-simulation systems at a minimum involving the user wearing a set of goggles with asmall monitor or display device in each eyepiece This allows the player to get a truly3D, stereo-vision experience Also, the VR headset allows the player to turn her headand have her view of the virtual world change accordingly, to match the new location atwhich she is “looking.” VR systems may also involve wearing gloves or full-body suitswhich detect the user’s motion and translate that into motion in the virtual world Vir-tual reality is one of the most commonly misused terms in all of computer game

parlance Many game developers with inflated senses of what they are doing will refer

to their RT3D first-person games as VR when, since they do not involve headsets, theyare really nothing of the kind Marketing people are particularly fond of misusing andabusing this term

VR: See Virtual Reality.

Wargame: When used in reference to computer games, wargame typically refers tostrategy-oriented games which employ gameplay based on pen and paper or boardwargames such as those made by Avalon Hill Computer wargames almost always sim-ulate historic battles, typically feature hexagon-based play-fields, and use turn-basedgameplay Games which are set in historical wars but are not strategic in nature are notgenerally referred to as wargames Classic examples of computer wargames include

Kampfgruppe and Eastern Front (1941), while more modern examples include Panzer General and Close Combat.

Selected Bibliography

The following references have been a great help to me in solidifying my ideas

about computer games I list them here as a sort of “recommended reading”list for those who wish to continue to learn about game design outside theconfines of this book

Books

Bogdanovich, Peter Who The Devil Made It New York: Knopf, 1997.

A fascinating collection of interviews with classic film directors Bogdanovich’sinterview style was my model for the interviews conducted in this book

Campbell, Joseph The Hero with a Thousand Faces New York: Bollingen

Foundation Inc., 1949 Reprint, Princeton: Princeton University Press, 1972.Campbell’s book is the definitive text on understanding the nature of myths, leg-ends, and heroic stories from throughout the ages

Crawford, Chris The Art of Computer Game Design Berkeley, CA: Osborne/

McGraw-Hill, 1984

Crawford’s seminal work was the first book about computer game design and wasthe inspiration for this book Despite its age in computer game industry terms, itremains largely relevant today Though it is out of print, it can currently be read in anumber of locations on the Internet, including www.erasmatazz.com

Hague, James Halcyon Days: Interviews with Classic Computer and Video

Game Programmers Issaquah, WA: Dadgum Games, 1997.

Hague’s book is an invaluable source of information about what it was like to work

in the gaming industry just as it was starting to establish itself All informationcomes straight from the source through a series of interviews with a broad range ofsubjects, including many whose work is discussed in this book: Eugene Jarvis, DaniBunten Berry, Dan Gorlin, Brian Moriarty, Ed Rotberg, Chris Crawford, and so on.The HTML-format book is available from Hague’s company, Dadgum Games, atwww.dadgum.com

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