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Cited by 49Artificial Intelligence in GamesDigital Games and MediaArt, Technology, and Culture

Expressive AI: Games and Artificial Intelligence

Open access
Mateas, Michael·2003·DiGRA Digital Library
DOI 10.26503/dl.v2003i1.99
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Abstract

In recent years, as dramatic increases in graphic sophistication began yielding diminishing returns, the technical focus in game design has been turning towards Artificial Intelligence (AI). While game AI might be considered a “purely technical” phenomenon not of interest to game designers and theorists, this paper argues that AI-based art and entertainment constitutes a new interdisciplinary agenda linking games studies, design practice, and technical research. I call this new interdisciplinary agenda expressive AI.

AI snapshot

Written from the paper’s full text.

TL;DR

This paper argues that AI-based art and entertainment constitutes a new interdisciplinary agenda, "expressive AI," linking games studies, design practice, and technical AI research. It proposes game AI as a "white box" language of behavior for analyzing and designing games, illustrated through Pac-Man's ghost AI and the author's Façade project.

Key findings

  • Game AI is defined not by specific techniques (pathfinding, neural nets, finite-state machines, etc.) but by a concern with behavior the player can read as produced by an intelligence with its own desires — related to Dennett's intentional stance and Newell's knowledge level.
  • Game AI is distinguished from game physics: physics is the "dead," purely mechanical part of a game, while AI is the part supporting a psychological read. The paper argues the enemies in *Space Invaders* are "really part of the physics of the game, not AI," since they move mechanically and appear to shoot randomly.
  • Analyzing Pac-Man shows the ghosts' behavior "defines the primary action of the game"; without them "there is no challenge in clearing a maze of pellets, and hence no game." Designer Toru Iwatani states the ghost algorithm was the most difficult part of designing the game.
  • Multiple conflicting player accounts of the ghosts' behavior (chasing, ambushing, wandering, randomness) are read as evidence of the AI design's success: simple algorithms yield behavior rich enough to support multiple interpretations and give the ghosts an "inner life." None of these accounts mention the attack waves Iwatani describes.
  • Two stated goals of game AI as research: it focuses on audience experience (traditional AI measures like time-to-task and error counts are "insufficient"; the AI must perform "with style"), and it supports human authorship (designers need architectural frameworks for particular visions, not "generic" reusable AI).

Methods

  • Conceptual/theoretical essay with illustrative case analysis, not an empirical study.
  • Analysis of Pac-Man's ghost AI draws on an interview with designer Toru Iwatani plus several gamer/player discussions of ghost behavior, comparing these accounts against each other.
  • Design discussion draws on the author's own work with Andrew Stern on *Façade*, a first-person interactive drama, as a concrete design space defined by an AI architecture.

Limitations

  • The paper states that Iwatani's interview description "is far from a complete description of the ghost AI" and that the author "has been unable to find a detailed description," so the Pac-Man analysis rests on incomplete and partly conflicting sources; Iwatani's account is "not detailed enough to resolve the dispute" among player readings.
  • Evident from the text: the argument is programmatic and illustrative rather than empirically tested — no formal evaluation, metrics, or systematic study of player experience is reported, and the Façade discussion is presented as the author's own design exploration rather than as evidence.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.26503/dl.v2003i1.99

Cites

18 of 18 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 13 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    There is little agreement on what the ghosts' behavior actually is in gamer discussions.

    “In fact, I have been unable to find a detailed description, but rather many gamer discussions hypothesizing about the ghost AI.It is interesting that in these discussions there is agreement that that ghost AI is central to the experience of the game, but little agreement on what the ghosts' behavior actually is.”
    Quote in the paperNot a substantial claim
  • Interpretationreasoning

    Much of Pac-Man's gameplay, and thus much of the player experience, is determined by the fine details of the ghosts' behavior.

    “Thus we can see that much of Pac-Man's gameplay, and thus much of the player experience, is determined by the fine details of the ghosts' behavior.”
    Quote in the paperSubstantial claim
  • Interpretationreasoning

    The ghosts in Pac-Man define the primary action of the game.

    “The ghosts in fact define the primary action of the game.”
    Quote in the paperSubstantial claim
  • Interpretationreasoning

    Game AI supports human authorship.

    “Game AI supports human authorship.”
    Quote in the paperNot a substantial claim
  • Interpretationreasoning

    For game design languages to be able to talk about behavior requires an engagement with game AI.

    “Thus for game design languages to be able to talk about behavior requires an engagement with game AI.”
    Quote in the paperNot a substantial claim
  • Classified as probably not a substantial claim. 38
  • May combine two claims. 9
  • The quote only partly states this claim. 1

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Findingnone given

    Iwatani's description in his interview is far from a complete description of the ghost AI.

    “Iwatani's description in this interview, however, is far from a complete description of the ghost AI.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    The turn towards game AI is manifest in increasing interest at game design venues, at AI research venues, and in game marketing that touts AI sophistication.

    “This change is manifest both in increasing interest in game AI at game design venues (e.g. the AI roundtable at the Game Developers Conferences), at AI research venues (e.g. the series of AAAI Symposia on AI and Interactive Entertainment [5,15,7]), and in game marketing that touts the sophistication of the AI rather than the graphic resolution or polygon count.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [5]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [15]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [7]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S4 (based).

    Findingreasoning

    The technical focus in game design has been turning towards Artificial Intelligence (AI).

    “In recent years, as dramatic increases in graphic sophistication began yielding diminishing returns, the technical focus in game design has been turning towards Artificial Intelligence (AI).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Game designers have called for a language of design, noting that designers currently lack a unified vocabulary for describing existing games and thinking through new games.

    “For several years, game designers have called for a language of design [11,2,12], noting that designers currently lack a unified vocabulary for describing the design of existing games and thinking through the design of new games.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [11]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [2]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [12]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    Academic game studies practitioners generally seal off implementation details, treating implementation as a black box that supports an autonomous discourse about games.

    “Like the design patterns and rules of game designers, academic game studies practitioners generally seal off implementation details, treating the implementation as a black box that supports an autonomous discourse about games.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Academic game studies is developing methods for analyzing games at an abstract content level above the implementation, drawing from humanistic disciplines.

    “Academic game studies is similarly developing various methods for analyzing games at an abstract content level above the implementation.”
    • Also stated in: § AI AND DESIGN Language for Design and Analysis · plain
      “Such analyses tend to draw methodologies and terminologies from various humanistic disciplines, producing a broad range of work that, for example, looks at games in terms of their use of space [10,24], as semiotic sign systems [13], as a narrative form [24,26], or in terms of the temporal relationships between actions and events [6].”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [10]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [24]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [13]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [6]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    To use game AI as a language for analysis requires opening up the black box of the implementation and considering the relationship between the generation of intelligent behavior, the player experience, and the cultural context of the game.

    “To use game AI as a language for analysis requires opening up the black box of the implementation and considering the relationship between the generation of intelligent behavior, the player experience, and the cultural context of the game.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The behavior of the ghosts in Pac-Man is critical to understanding the game.

    “The behavior of the ghosts is critical to understanding the game.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based). May combine two claims.

    Interpretationreasoning

    This white box language is the language of behavior, the language of game AI.

    “This is the language of behavior, the language of game AI.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    In the context of game analysis and design, expressive AI provides a language for talking about

    “In the context of game analysis and design, expressive AI provides a language for talking about”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based). The quote only partly states this claim.

    Interpretationreasoning

    AI-based art and entertainment constitutes a new interdisciplinary agenda linking games studies, design practice, and technical research (expressive AI).

    “While game AI might be considered a”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    Design patterns and design rules are usually articulated at a level of abstraction above implementation details, dealing purely with relationships between visual elements, game rules, and player interaction.

    “Both design patterns, which name and describe design elements, and the closely related notion of design rules, which offer imperative advice in specific design situations, are usually articulated at a level of abstraction above the implementation details of the game, dealing purely with relationships between visual elements, game rules, and player interaction.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The multiple readings of the ghosts' behavior speak to the success of the AI design.

    “The fact that there are these multiple readings of the ghosts' behavior in fact speaks to the success of the AI design.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S1 (asserted), S2 (checkable).

    Premisereasoning

    What links game AI practices is a concern with

    “What links these practices together under the single term”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    In the context of AI research, expressive AI opens up a new technical research agenda.

    “In the context of AI research, expressive AI opens up a new technical research agenda.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based). May combine two claims.

    Interpretationnone given

    Game AI is not just about hyperrational problem solving, but also about creating a sense of aliveness, the sense that there is an entity living within the computer that has its own life independently of the player and cares about how the player's actions impact this life.

    “But game AI is not just about hyperrational problem solving, but also about creating a sense of aliveness, the sense that there is an entity living within the computer that has its own life independently of the player and cares about how the player's actions impact this life.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Game AI lies at the intersection of player perception (the player is able to read part of the game behavior as alive) and the game code that supports this perception.

    “Game AI lies at the intersection of player perception (the player is able to read part of the game behavior as alive) and the game code that supports this perception.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    There is a place for a

    “However, this paper argues that there is a place for a game language that opens up the box and considers the implementation, a”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    The relatively simple algorithms of the ghost AI yield a richness and unpredictability of behavior that supports multiple interpretations, giving the ghosts an

    “The relatively simple algorithms of the ghost AI yields a richness and unpredictability of behavior that supports multiple interpretations, giving the ghosts an”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    For game designers, the game AI strongly influences the design space.

    “For game designers, the game AI strongly influences the design space.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The gameplay can't be understood without a

    “The gameplay can't be understood without a”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    Opening up the game AI is essential not only for analysis, but as part of the language of design.

    “Thus, opening up the game AI is essential not only for analysis, but as part of the language of design.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Game AI focuses on audience experience.

    “Game AI focuses on audience experience.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    The game AI must not only accomplish tasks within the game world, but do it with style.

    “The game AI must not only accomplish tasks within the game world, but do it with style.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    For AI researchers, game AI offers new high-level research goals, thus opening up new technical challenges.

    “And for AI researchers, game AI offers new high-level research goals, thus opening up new technical challenges.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    Game design can have a real impact on the technical practice of AI, opening up a new research agenda that asks novel technical research questions.

    “While the technical practice of AI has an influence on the design and analysis of games, conversely, game design can have a real impact on the technical practice of AI, opening up a new research agenda that asks novel technical research questions.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The AI's fundamental goal is to create an experience for the player.

    “The AI's fundamental goal is to create an experience for the player.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The behavioral design space is structured by the architecture and algorithms of the game AI.

    “The behavioral design space is structured by the architecture and algorithms of the game AI.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    Much of the question of interactive story revolves around whether and how a game can provide moment-by-moment interaction that produces an immediate sense of agency while helping to structure long-term interaction into a dramatically pleasing arc without diminishing the sense of agency.

    “Much of the question of interactive story revolves around whether and how a game can provide moment-by-moment interaction that produces an immediate sense of agency while helping to structure long-term interaction into a dramatically pleasing arc (e.g.complication, crisis, climax and resolution) without diminishing the sense of agency.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    To really understand Pac-Man, to understand the player experience and the player interpretations supported by this experience, would require a detailed understanding of the ghost AI.

    “So to really understand Pac-Man, to understand the player experience and the player interpretations supported by this experience, would require a detailed understanding of the ghost AI.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    A full understanding of a game requires understanding the behavior of the

    “A full understanding of a game requires understanding the behavior of the”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationnone given

    For game analysis, game AI is the language of intentional behavior.

    “For game analysis, game AI is the language of intentional behavior.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The AI architecture must support game artists in expressing the behavioral potential needed for a specific design.

    “Because game AI is a fundamental part of the player experience, the AI architecture must support game artists in expressing the behavioral potential needed for a specific design.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Game AI is more than an implementation issue only of interest to game designers.

    “Game AI is more than an implementation issue only of interest to game designers.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Since game AI is a deep part of the design, novel AI architectures and approaches will need to be continuously developed within the context of specific designs and particular creative visions.

    “Since game AI is a deep part of the design, novel AI architectures and approaches will need to be continuously developed within the context of specific designs and particular creative visions.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationcitation

    Game AI is an instance of expressive AI, AI research that takes AI-based art and entertainment as a first class problem.

    “Game AI is an instance of expressive AI, AI research that takes AI-based art and entertainment as a first class problem [18,19,20].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [18]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [19]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [20]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The measures of effectiveness used in traditional AI research, such as time to accomplish a task, number of errors, and so forth, are insufficient for guiding work in game AI.

    “The measures of effectiveness used in traditional AI research, such as time to accomplish a task, number of errors, and so forth, are insufficient for guiding work in game AI.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    These questions of interactive story are primarily questions of behavior, and can thus be most profitably explored within concrete design spaces defined by specific AI approaches, rather than through abstract argumentation.

    “These are primarily questions of behavior, and can thus be most profitably explored within concrete design spaces defined by specific AI approaches, rather than through abstract argumentation.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationnone given

    Game designers need architectural frameworks within which they can express their particular visions, rather than

    “Rather than”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationnone given

    AI, as a language of behavior, operates at the interface between everyday language for describing intentional behavior and technical implementations that provide a specific, narrow interpretation of this everyday terminology.

    “AI, as a language of behavior, operates at the interface between everyday language for describing intentional behavior (e.g.”
    Quote in the paperNot a substantial claim
40 of 40

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Citation 26 has no reference entry

    Minor

    The text cites reference 26 for work on games as narrative, but the provided reference list ends at 25.

  • Dramatic-beats citation points to a different work

    Minor

    The discussion cites [17] for dramatic beats, but reference 17 is a paper on semiotic analysis; the listed screenwriting book is reference 16.

  • Newell citation points to Ryan

    Minor

    The text cites [25] for Newell's knowledge level, but reference 25 is by Ryan. Newell's The Knowledge Level is reference 24.

  • Pac-Man ghost quotation cites an AI symposium

    Minor

    The quoted description of individual Pac-Man ghosts is attributed to [14], but reference 14 is an AI symposium volume; the Pac-Man source appears under reference 13.

  • Citation for the authors' architecture points to Murray

    Minor

    The text attributes beat goals and conversational handlers in the authors' architecture to [23], but reference 23 is Murray's Hamlet on the Holodeck, not a work by the authors.

  • Iwatani interview cites a screenwriting book

    Minor

    The cited reference [16] is McKee's screenwriting book, not the Iwatani interview. The interview is listed within reference 15.

  • AI symposium citation points to an interview book

    Minor

    The text cites [15] as part of a series of AAAI symposia, but reference 15 is a book of programmer interviews. The 2001 symposium is listed as reference 14.

7 of 7

Cites

Flagged first, then by citations

1 of the 19 references couldn’t be matched to a known paper.

Research works printed but not linked: 5

  1. Dobson, W. (Ed.). Papers from the 2000 AAAI Spring Symposium on Artificial Intelligence and Interactive Entertainment. Menlo Park, CA: AAAI Press. 2000.
  2. Forbus, K. and El-Nasr, M. (Eds.). Papers from the 2002 AAAI Spring Symposium on Artificial Intelligence and Interactive Entertainment. Menlo Park, CA: AAAI Press. 2002.
  3. Laird, J., and van Lent, M. (Eds.). Papers from the AAAI Spring Symposium on Artificial Intelligence and Interactive Entertainment. Menlo Park, CA: AAAI Press. 2001.
  4. Mateas, M. Expressive AI: A Semiotic Analysis of Machinic Affordances. Proceedings of the 3 rd Conference on Computational Semiotics and New Media, University of Teesside, UK. 2003.
  5. Mateas, M. & Stern, A. Integrating Plot, Character and Natural Language Processing in the Interactive Drama Facade. In Göbel, S., Braun, N., Spierling, ,U., Dechau, J., and Diener, H. (Eds.) Proceedings of Technologies in Interactive Digital Storytelling and Entertainment. ZDGV, Darmstadt, Germany, 2003.

Cited by

Sorted by citations

Related

Authors
Mateas, M.
Affiliations
Georgia Institute of Technology (US)
Corresponding author
Mateas, Michael
ORCID
Mateas, Michael
Venue
DiGRA Digital Library
Publisher
Digitial Games Research Association DiGRA
Published
2003-01-01
Volume
2
ISSN
2342-9666
DOI
10.26503/dl.v2003i1.99
OpenAlex
W2175156397
Cited by
49
References
19
Citations by year
2026: 1 · 2025: 1 · 2024: 4 · 2023: 1 · 2022: 2 · 2021: 3 · 2020: 2 · 2019: 1 · 2018: 4 · 2017: 1 · 2016: 5 · 2014: 3 · 2013: 2 · 2012: 2
FWCI
1.22
Type
conference paper
Language
en
Open access
Locations
Digital Games Research Association Conference
Topics
  • Physical Sciences › Computer Science › Artificial Intelligence › Artificial Intelligence in Games
  • Social Sciences › Sociology and Political Science › Digital Games and Media
  • Social Sciences › Arts and Humanities › Visual Arts and Performing Arts › Art, Technology, and Culture
Keywords
game AI, game design, game studies, entertainment, interdisciplinary research

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

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