Encoding and Generating
Videogame Mechanics

Tutorial session
IEEE Computational Intelligence and Games 2012

Mark J. Nelson
ITU Copenhagen

Encoding? Generating? Mechanics?

Game generation versus PCG

As in regular game development, what constitutes an asset can have gray areas.

This tutorial's approach

I'll be pulling up a few of the papers during the talk. To follow along:

(If you're reading this online after my talk, that link is a better summary than reading these slides!)

First cluster of systems: board games

A significant chunk of work, including the earliest.


B. Pell, "METAGAME in symmetric chess-like games." In Heuristic Programming in Artificial Intelligence 3 – The Third Computer Olympiad. Ellis Horwood, 1992.

Metagame encoding

Design guideline:

(See example on p. 14)

Metagame generator

Probabilistic grammar, which is possible due to the encoding.

Other features:

Metagame control knobs

Balanced board games

Significantly smaller representation space than Metagame, in a subset of Zillions of Games ZRF format.

Space searched with a genetic algorithm.

V. Hom & J. Marks, "Automatic design of balanced board games", AIIDE 2007.

Evolutionary game design

Ludi proposes a much more ambitious framework:

C. Browne & F. Maire, "Evolutionary game design", TCIAIG 2(1), 2010.

Second cluster of systems: graphical logics

Vaguely an old-school arcade style:

Designing graphical-logic games

What makes an interesting graphical-logic game?

Evolving graphical-logic games

Proposal: "a game is fun if it is learnable but not trivial"

J. Togelius & J. Schmidhuber, "An experiment in automatic game design", CIG 2008.

Sculpting game spaces

Proposal: declaratively specify the boundaries/contents of a game space

A.M. Smith & M. Mateas, "Variations Forever: Flexibly generating rulesets from a sculptable design space of mini-games", CIG 2010.

Multi-faceted generation

Proposal: Integrate PCG concerns such as level and NPC generation into the rule-generation system

M. Cook & S. Colton, "Multi-faceted evolution of simple arcade games", CIG 2011.

Could we generate something like this?

Factoring game design

Four design-knowledge areas:

M.J. Nelson & M. Mateas, "Towards automated game design", AI*IA 2007.

Game-generation systems

What do game-generation systems generate?

Other possibilities:

Generating concrete representations

Given an abstract game, can we assign audiovisual elements and layout to its abstract state/events, and make it playable?

J. Orwant, "EGGG: Automated programming for game generation", IBM Systems Journal 39(3-4), 2000.

Generating thematic mappings

Proposal: an auto-skinning system

M.J. Nelson & M. Mateas, "Towards automated game design", AI*IA 2007.
M.J. Nelson & M. Mateas, "An interactive game-design assistant", IUI 2008.

Generating rhetorical games

Can the mapping be more than just "making sense"?

M. Treanor, B. Blackford, M. Mateas, I. Bogost, "Game-O-Matic: Generating videogames that represent ideas", PCG 2012.
M. Treanor, B. Schweizer, I. Bogost, M. Mateas, "The micro-rhetorics of Game-O-Matic", FDG 2012.

Connections to other areas

Game ontology

Game-mechanic encodings are formal specifications about what games "are" and "contain", at least in a particular domain.

Related investigations:

J.P. Zagal et al., "Towards an ontological language for game analysis", DiGRA 2005
J. Juul, "Swap adjacent gems to make sets of three", Artifact Journal, 2007.
J.P. Zagal, C. Fernandez-Vara, M. Mateas, "Rounds, levels, and waves: The early evolution of gameplay segmentation", Games and Culture, 2008.

Design-support systems

Also may have formal encoding of game mechanics.

J. Dormans, "Machinations: Elemental feedback structures for game design", GAMEON-NA 2009.
A.M. Smith, M.J. Nelson, M. Mateas, "Computational support for play testing game sketches", AIIDE 2009.

Proposed challenge:
extensible, reusable domains

Modular/extensible ontologies?

M.J. Nelson & M. Mateas, "Recombinable game mechanics for automated design support", AIIDE 2008.
M. Mateas & N. Wardrip-Fruin, "Defining operational logics", DiGRA 2009.

Submit to FDG 2013!

If you're interested in doing or seeing more of this kind of work, consider submitting to and attending Foundations of Digital Games 2013.