Purpose
This page defines core game design vocabulary. Terms are grounded in their primary source and flagged where definitions are contested or vary across the literature. As more sources are ingested, additional definitions and comparisons will be added here.
Format per entry:
Working definition. — Source Contested/variants: where other authors use the term differently.
Cross-references link to fuller concept pages where they exist.
Game
A problem-solving activity, approached with a playful attitude. — Schell (2008, source-art-of-game-design)
Schell arrives at this through analysis of ten qualities commonly attributed to games: voluntary entry, goals, conflict, rules, win/loss states, interactivity, challenge, endogenous value, engagement, and formal closure.
Contested/variants:
- Salen & Zimmerman (2003): “a closed, formal system that engages players in structured conflict and resolves its uncertainty in an unequal outcome”
- Costikyan (1994): “an interactive structure of endogenous meaning that requires players to struggle toward a goal”
- Suits (1978): “the voluntary attempt to overcome unnecessary obstacles”
The definitions converge on: voluntary, rule-bound, goal-directed, and interactive. They diverge on whether narrative, uncertainty, or conflict are essential.
See also: game-definition, elemental-tetrad
Play
Manipulation that satisfies curiosity. — Schell (2008, source-art-of-game-design)
Play is exploratory and intrinsically motivated. The distinction between play and work is attitudinal, not inherent to the activity — the same act can be play or work depending on why the person is doing it.
Contested/variants:
- Huizinga (1938, Homo Ludens): play as a “free activity standing quite consciously outside ordinary life”
- Suits: play as voluntary adoption of unnecessary constraints
Fun
Pleasure with surprises. — Schell (2008, source-art-of-game-design)
Fun requires novelty or unexpectedness — predictable pleasure is comfort, not fun. Schell identifies multiple types of pleasure a game can provide (sensory, fantasy, narrative, challenge, fellowship, discovery, expression, submission).
Contested/variants:
- Koster (2004, A Theory of Fun): fun is the act of learning patterns; when patterns are mastered, the game stops being fun. Fun ≈ the feeling of learning.
- These two definitions are complementary: surprise (Schell) and learning (Koster) both point at novelty and cognitive engagement as the source of fun.
Toy
An object you play with. A good toy is an object that is fun to play with. — Schell (2008, source-art-of-game-design)
A toy has intrinsic playable quality independent of goals or rules. The concept is useful in design: Lens #15 (The Toy) asks whether your game is fun to interact with before any goals are imposed. Many successful games start life as toys (a satisfying movement system, a fun physics interaction).
Player experience
The moment-to-moment and overall psychological experience of a person playing a game. In Schell’s framework, player experience is the target of design — the game itself is only a means to produce the experience.
“The game is not the experience. The game enables the experience, but it is not the experience itself.” — Schell (2008, source-art-of-game-design)
This distinction matters practically: two games with identical rules can produce radically different experiences depending on aesthetics, pacing, and context. Designers must hold player experience as the primary measure of success, not mechanical elegance.
The experience exists in the player’s mind, not in the game artefact. This makes it difficult to observe directly — hence the importance of introspection, playtesting, and the “skin and skeleton” discipline of holographic-design.
Game design
The act of deciding what a game should be. — Schell (2008, source-art-of-game-design)
A continuous decision-making process throughout development — not confined to pre-production. Thousands of decisions across all four elements of the elemental-tetrad.
Game designer vs. game developer
- Game developer — anyone involved in the creation of a game: engineers, artists, animators, writers, producers, designers.
- Game designer — anyone who makes decisions about what the game should be. Designer is a role, not a person. Most developers act as game designers at some point during development.
Understanding this distinction matters for students entering teams — design responsibility is distributed, not concentrated in a single “designer” role. (Schell, source-art-of-game-design)
Mechanics
The procedures and rules of a game: what players can and cannot do, the goals they pursue, and what happens when they act.
Mechanics are what distinguish games from all other entertainment media. Books, films, and music involve technology, story, and aesthetics — but not mechanics. (Schell, source-art-of-game-design)
Schell identifies six primary mechanic types:
- Space — the functional geometry of the game world
- Objects, attributes, and states — what exists and how it changes
- Actions — the verbs available to the player
- Rules — what is permitted, required, or forbidden
- Skill — what the player must learn or develop
- Chance — randomness and probability
Contested/variants (MDA): In the MDA framework (Hunicke, LeBlanc, Zubek, 2004), “Mechanics” has a narrower meaning — the specific rules and data representations. MDA separates “Mechanics” from “Dynamics” (runtime behaviour) and “Aesthetics” (emotional response), where Schell uses a broader tetrad.
See also: elemental-tetrad, mda-framework
Dynamics
In the MDA framework, dynamics are the runtime behaviour that emerges when mechanics operate on player input over time. The gap between intended mechanics and actual dynamics is where many design problems live.
Mechanics → (runtime) → Dynamics → (player response) → Aesthetics [MDA]
Schell does not use “dynamics” as a distinct term — his equivalent is emergence (see below). The MDA distinction is useful because a mechanic that looks balanced on paper may produce unexpected dynamics in play.
Note: MDA’s “Aesthetics” refers to emotional responses (fun, fantasy, fellowship etc.) — not to visual/audio aesthetics as Schell uses the term.
See also: mda-framework, elemental-tetrad
Aesthetics (Schell)
How a game looks, sounds, smells, tastes, and feels — the sensory and perceptual dimension of the experience. One of the four elements of Schell’s elemental-tetrad. The most directly visible element to players; has the most immediate relationship to player experience.
Important distinction: Schell’s “Aesthetics” = sensory presentation. MDA’s “Aesthetics” = emotional response categories (fun types). These are different uses of the same word — be explicit about which sense is meant when cross-referencing.
Technology (as a game element)
The medium in which a game operates — not exclusively digital. Paper, dice, cards, plastic components, and software are all technology in Schell’s sense. Technology enables certain mechanics and prohibits others; it is the least visible element to players but shapes everything the other three elements can do.
One of the four elements of the elemental-tetrad. (Schell, source-art-of-game-design)
Magic circle
The conceptual boundary that separates the game world from ordinary reality. Inside the magic circle, a game’s rules apply and objects gain endogenous value (value that exists only within the game context). Outside it, those rules and values cease to apply.
Originated with Huizinga (Homo Ludens, 1938). Schell re-frames it as the mind’s internal problem-solving space — a simplified model of reality that allows effective reasoning within the game’s constraints.
See also: Endogenous value (below), game-definition
Endogenous value
Value that exists only within the context of a game — it does not transfer to the real world. A chess piece, a game currency, or a high score has endogenous value to players deeply engaged in the game, but is meaningless outside of it.
Endogenous value is partly what creates player investment and makes games emotionally engaging. Designing for it means creating objects, currencies, and achievements that players genuinely care about within the game context. (Schell, Lens #5, source-art-of-game-design)
Rules
The formal constraints that define what is and is not permitted in a game. Rules create the space of possible play. Without rules, there is no game — only a toy or free play.
Good rules are:
- Complete — they cover all situations that arise
- Consistent — they do not contradict each other
- Understood — players must be able to grasp them (Schell, Lens #26, source-art-of-game-design)
Rules operate at multiple levels: core rules (the fundamental logic), operational rules (how to play in practice), and implicit rules (social conventions not formally stated).
Goals
The objectives a game gives players — the conditions for winning, progressing, or succeeding. Goals create purpose and direction; without them, mechanics are a toy rather than a game.
Effective goals are:
- Clear — players know what they are aiming for
- Achievable — but not trivially so
- Rewarding — success feels meaningful
Games typically have layered goals: an immediate goal (survive this encounter), a short-term goal (complete this level), and a long-term goal (complete the game). Maintaining all three layers keeps players engaged across different time scales. (Lens #25, Schell, source-art-of-game-design)
Interactivity
The property of games that distinguishes them from passive media — players take actions that affect the state of the game, and the game responds. Interactivity creates the feedback loop at the heart of gameplay.
Schell describes the loop of interaction: the player perceives the game state → forms a goal → decides on an action → performs it → the game responds → repeat. The quality and speed of this loop has a direct effect on how responsive and satisfying the game feels.
Feedback
The game’s response to player actions — communicating what happened, whether it was successful, and what changed. Feedback is the connective tissue of interactivity; without it, the player cannot learn or adapt.
Feedback can be:
- Immediate — visual/audio response to an action (a hit effect, a sound cue)
- Informational — score changes, health bars, status displays
- Narrative — story consequences of player choices
Good feedback is clear, timely, and appropriately proportioned to the significance of the action. Lens #57 (Feedback) and Lens #58 (Juiciness) both address this. (Schell, source-art-of-game-design)
See also: game-feel (the perceptual quality of feedback)
Juiciness
Informal term for the density and expressiveness of feedback — a game is “juicy” when every action produces a satisfying cascade of audio, visual, and haptic responses. Juiciness makes games feel alive and rewarding to interact with at the micro level.
Distinct from functional feedback: juiciness is about feel and delight, not information. A button press can be perfectly functional but feel dead; adding screen shake, a sound, and a particle burst makes the same action feel satisfying. (Lens #58, Schell, source-art-of-game-design)
See also: game-feel
Challenge
The degree of difficulty a game presents relative to the player’s skill level. Challenge is necessary for engagement — too little produces boredom, too much produces frustration. The productive zone between these is described by flow theory.
Challenge operates at multiple levels: mechanical challenge (can the player execute the required actions?), strategic challenge (can they make the right decisions?), and cognitive challenge (can they understand the system?). (Lens #31, Schell, source-art-of-game-design)
Flow
A psychological state of complete engagement and energised focus, first described by Csikszentmihalyi (1990). In games, flow occurs when challenge is appropriately matched to skill — neither too easy (boredom) nor too hard (anxiety).
The flow channel is the narrow band of challenge-to-skill ratio that produces this state. Maintaining flow requires the game to continuously adapt challenge as the player’s skill grows — through difficulty scaling, new mechanics, or escalating enemy behaviour.
Flow is a dynamic target, not a static condition: a player in flow is moving through the channel, not sitting in it. (Lens #18, Schell, source-art-of-game-design)
See also: flow (full concept page, to be created)
Emergence
The appearance of complex, unpredictable behaviour from simple rules. Emergent gameplay arises when the interactions between mechanics produce outcomes the designer did not explicitly script.
Emergence is generally desirable: it extends the life of a game, produces unique player stories, and creates depth without added complexity. It is also difficult to control — emergent behaviour can undermine balance or produce exploits. (Lens #23, Schell, source-art-of-game-design)
Examples: the unpredictable social dynamics of Dwarf Fortress; the unscripted stories of DayZ; the accidental tactics that arise in fighting games.
Terms introduced by Poole (Trigger Happy, 2000)
The following terms appear in Poole’s analysis. Some are standard industry vocabulary; others are Poole’s own critical coinages.
(Poole, Trigger Happy, see source-trigger-happy)
God game
A simulation genre in which the player assumes an omnipotent perspective over a self-contained world — a city, civilisation, ecosystem, or social group. The player does not control a character but instead shapes the rules, layout, and conditions under which simulated agents live.
The God game genre appeals to a specifically narcissistic pleasure: omnipotent control over a digital pet world. — Poole, paraphrase (source-trigger-happy)
Examples: SimCity, Civilisation, Theme Hospital, The Sims, Dungeon Keeper.
The pleasure of the God game is distinct from action or strategy games — it is closer to Schell’s “submission” aesthetic (surrendering to a system’s logic) combined with the fantasy of total creative control.
See also: genre-taxonomy
Combo / Combo system
In fighting games and action games, a combo is a sequence of button inputs executed in precise order and timing to produce a specific, preset outcome (typically a multi-hit attack). The sequence is predetermined by the game’s design rather than constructed freely by the player.
Poole uses the combo system as a counter-example to tactical depth: systems built around memorised preset sequences prescribe outcomes rather than enabling player invention, paradoxically reducing player-agency despite apparent input complexity.
“Robotron gives you two joysticks: one to move, one to fire. Simple. But with those tools, there is a huge tactical potential of feints, misdirections and apocalyptic vengeance.” — Poole, Ch. 2 (source-trigger-happy)
See also: player-agency, genre-taxonomy
FMV (Full Motion Video)
Pre-rendered or live-action video sequences embedded within a game. FMV was prominent in the early 1990s CD-ROM era (Wing Commander, Myst, Night Trap) and is still used for cutscenes and narrative delivery.
Poole’s critique: FMV sequences return the player to a passive role, which is categorically weaker in games than in film. The player’s attention is pulled from doing to watching — the inverse of what makes games valuable as a medium.
Modern usage: “cutscene” is more common than “FMV” for in-engine rendered sequences; “FMV” now typically refers specifically to live-action or pre-rendered video. The design tension Poole identifies (active vs. passive experience) remains live.
See also: games-vs-film, player-agency
Deformed aesthetic / Chibi
The visual style common in Japanese game character design characterised by exaggerated, simplified, non-naturalistic proportions — typically oversized heads, large expressive eyes, and compressed bodies. Sometimes called chibi (from Japanese: “small” or “short”).
Poole argues this is a deliberate artistic preference rooted in Edo-period Japanese woodblock print traditions (ukiyo-e), not a technical limitation. The deformed aesthetic has its own internal logic and is aesthetically superior for certain types of characters and experiences — it prioritises expressiveness and emotional legibility over physical realism.
“Unrealism in videogames need not be a handicap; it can be a positive, deliberate pleasure.” — Poole, Ch. 7 (source-trigger-happy)
Contrast with: Motion capture (see below), photorealism in games.
Motion capture (design critique)
Motion capture (mocap) is the technology of recording real human movement to animate digital characters. Poole offers a design-critical perspective: mocap is aesthetically limiting because it constrains virtual movement to what is physically possible for human performers.
Game characters are freed from human biomechanical constraints — they can move, bend, and act in ways no human can. Mocap forecloses this expressive freedom in favour of realism. This is an argument against using mocap as the default and for using stylised, authored animation where appropriate.
See also: Deformed aesthetic (above), genre-taxonomy
Terms introduced by Adams (Fundamentals of Game Design, 2014)
The following terms are used precisely by Ernest Adams and are important for any student using this wiki alongside that textbook.
Gameplay
Adams defines gameplay as consisting of two things: the challenges the player must face and the actions the player may take to address them. These two elements form the atomic unit of game design.
“Gameplay consists of: the challenges that a player must face to arrive at the object of the game, and the actions that the player is permitted to take to address those challenges.” — Adams, Ch. 1 (Adams, Fundamentals of Game Design, see source-fundamentals-game-design)
Every other element of a game (story, aesthetics, technology) should serve the challenge/action relationship. See challenge-types for a full taxonomy.
Absolute difficulty
The difficulty of a challenge in objective terms, combining two factors:
- Intrinsic skill required: the skill needed to surmount the challenge given unlimited time
- Stress: the difficulty added by time pressure
Absolute difficulty says nothing about how hard the player perceives the challenge to be — that depends also on power provided and in-game experience. See game-balance for the full perceived difficulty formula.
Harmony
A quality of games (and game worlds) first identified by designer Brian Moriarty: the feeling that all parts of a game belong to a single, coherent whole. Harmony is not an explicit mechanic but a global aesthetic property of the design.
“Harmony isn’t something you can fake. You don’t need anyone to tell you if it’s there or not… Games with harmony emerge from a fundamental note of clear intention.” — Moriarty, quoted in Adams, Ch. 1
Designers who pile on features without asking whether they fit undermine harmony. The test is simple: does this element feel like it belongs?
Competition modes
Adams identifies six modes describing how players relate to each other in a game:
| Mode | Description |
|---|---|
| Two-player competitive | Classic head-to-head |
| Multiplayer competitive | Everyone for himself (deathmatch) |
| Multiplayer cooperative | All players vs. situation |
| Team-based | Groups competing |
| Single-player | Player vs. the game |
| Hybrid | Cooperation within a competitive structure (Diplomacy) |
Elegance
Adams’ term for the highest expression of game design craft: when artistic and functional elements come together in such a way that the rules are few but deep, the aesthetics reinforce the mechanics, and nothing feels unnecessary.
Game design is a craft, not pure art and not pure engineering. Elegance is its signature achievement.
Terms introduced by Bond (Introduction to Game Design, Prototyping, and Development, 3rd ed., 2014)
The following terms appear in Bond’s text and are important for students using this wiki alongside that textbook.
(Bond, Introduction to Game Design, Prototyping, and Development, see source-introduction-game-design-prototyping)
Lusory attitude
Bernard Suits’ term for the attitude required for genuine play: the voluntary willingness to follow game rules as the means of winning, for the joy of winning by those rules.
“The voluntary attempt to overcome unnecessary obstacles.” — Suits (quoted by Bond)
Three participant types: players (possess the lusory attitude), cheaters (violate rules while pursuing the goal), spoilsports (reject the game entirely). Both cheating and spoilsporting undermine the magic circle, but in different ways.
See also: game-definition
Agon / Alea / Ilinx / Mimicry
Caillois’ four fundamental play types (from Man, Play and Games, 1958):
| Type | Meaning | Core pleasure |
|---|---|---|
| Agon | Contest | Competitive mastery; winning through skill |
| Alea | Dice / chance | Surrendering to luck; fate |
| Ilinx | Whirlpool | Vertiginous sensation; disruption of equilibrium |
| Mimicry | Make-believe | Inhabiting another identity; roleplay |
Most games blend types. Agon vs. alea tension (skill vs. luck) is a central multiplayer balance problem.
See also: game-definition, game-balance
Fun (Burgun)
Keith Burgun’s definition: fun must be simultaneously enjoyable (pleasant in the moment) + engaging (demands attention) + fulfilling (provides growth or accomplishment). “Fun” in casual usage often means only “enjoyable” — Burgun argues the missing component is usually fulfilment.
See also: Fun (Schell, above), game-definition
Iterative design
Bond’s structured model of the design process: Analysis → Design → Implementation → Testing, looped repeatedly. Each iteration answers one design question. “Game design is 1% inspiration and 99% iteration” (Chris Swain, quoted by Bond).
See also: prototyping, playtesting
Inscribed / Dynamic / Cultural layers
Bond’s three-layer model from the layered-tetrad:
- Inscribed — developer-authored; exists pre-play (rules, art assets, scripts)
- Dynamic — emerges during play; shared ownership (player experience, emergent behaviour)
- Cultural — built by the player community beyond play (speedrunning, fan art, mods)
The inscribed layer is fully within designer control. The cultural layer is fully outside it.
Tissue playtester
A playtester whose naïve first-impression has not been used up — they have not seen the game (or feature) before. Named for their single-use nature: once they have seen the game, their first impression cannot be recaptured.
Invaluable for: tutorial testing, first-level difficulty, emotional impact. Plan their use carefully on student projects.
See also: playtesting
Investigator (playtesting)
Bond’s term for the person who administers a playtest session — prepares the environment, runs the script, observes, takes notes. Distinct from the playtester who participates. In small teams, one person may do both, but separating the roles reduces confirmation bias.
See also: playtesting
Terms introduced by Koster (A Theory of Fun for Game Design, 2005)
The following terms are central to Koster’s cognitive theory of fun. They recur frequently in game studies writing.
(Koster, A Theory of Fun, see source-theory-of-fun, fun-as-learning)
Chunking (Koster)
The brain’s process of compressing a mastered pattern or skill into an automated routine that no longer requires conscious attention. Getting dressed, driving a familiar route, playing a known chord — these actions are “chunked” and fire as units without deliberate thought.
In games: once a player has chunked all of a game’s core patterns, the game becomes boring. Design must keep the player just ahead of their own chunk-formation.
“The brain doesn’t particularly want to have to deal with it again.” — Koster, Ch. 2
See also: fun-as-learning, flow
Grokking (Koster, via Heinlein)
From Robert Heinlein’s Stranger in a Strange Land: to grok something is to understand it so completely that you have become one with it. Koster uses it for the state in which all three levels of processing — conscious, intuitive, and reflex — are fully aligned with a pattern. Grokking a game = the game is finished teaching; boredom follows.
Distinct from “understanding” (conscious level only) and “intuitive grasp” (first two levels). Grokking implies the reflex/muscle-memory level is also engaged.
See also: fun-as-learning
Fiero (Koster, from psychology)
Italian: pride. The emotion of personal triumph over adversity — the involuntary fist-pump, the shout of “yes!” when beating something hard. A signal to others of one’s value.
Fiero is one of the emotions games are exceptionally good at producing. It requires genuine challenge — a task that almost defeated the player. It cannot be manufactured by making the game trivially easy.
Also cited in: Adams/Bateman player emotion survey (see game-definition)
See also: fun-as-learning, challenge-types
Schadenfreude (Koster, from psychology)
German: harm-joy. The gloating pleasure felt when a rival fails. In games: the satisfaction at watching an opponent lose, the pleasure of the kill streak counter. A status-signalling emotion — it communicates “I am above you.”
Koster notes this is a form of social status play, enjoyable but distinct from fun-as-learning.
See also: fun-as-learning
Naches (Koster, from psychology)
Yiddish. The pride or pleasure felt when someone you mentored or cared for succeeds. In games: the mentor’s pleasure in a student surpassing them; the feeling when a player you guided through a level wins. A tribal continuance signal.
Also cited in: Adams/Bateman player emotion survey (see game-definition)
See also: fun-as-learning, player-centric-design
Kvell (Koster, from psychology)
Yiddish. The pride felt when bragging about someone you mentor. Distinct from naches (pride at their success) — kvell is specifically the social signal of claiming credit for nurturing that success.
See also: fun-as-learning
Related
- game-definition — Fuller treatment of what constitutes a game, including Adams’ four-element definition
- elemental-tetrad — Mechanics, Story, Aesthetics, Technology
- layered-tetrad — Bond’s three-layer extension of the Elemental Tetrad
- design-lenses — The 100 lenses methodology
- lenses-reference — Full lens list
- holographic-design — Skin and skeleton
- interest-curves — Pacing and engagement
- player-agency — Interactivity, combo paradox, Poole’s control-centric definition
- games-vs-film — FMV and the passive/active distinction
- genre-taxonomy — God games, fighting games, and genre-specific mechanics
- semiotics-of-games — How game signs are read
- flow — Flow state
- game-feel — Micro-level feel and juiciness
- mda-framework — MDA framework comparison
- challenge-types — Adams’ taxonomy of challenge categories
- game-balance — Difficulty model and positive feedback
- player-centric-design — Adams’ design philosophy
- internal-economy — Mechanics layer governing resource flow
- fun-as-learning — Koster’s full theory
- source-art-of-game-design
- source-trigger-happy
- source-fundamentals-game-design
- source-introduction-game-design-prototyping
- source-theory-of-fun