Game designers have called for a design language (Costikyan 1994; Church 1999; Kreimeier 2002; Kreimeier 2003), noting that designers currently lack a unified vocabulary for describing the design of existing games and thinking through the design of new games. Many of the proposed approaches focus on offering aid to the designer, either in the form of design patterns (Kreimeier 2002; Bjork et al. 2003), which name and describe design elements, or in the closely-related notion of design rules, which offer advice and guidelines for specific design situations. (Fabricatore et al. 2002; Falstein 2004) Other analyses draw methods and terminology from various humanistic disciplines. For example, games have been analyzed in terms of their use of space (Jenkins 2003), as semiotic sign systems (Kücklich 2003), as a narrative form (Murray 1997; Carlquist 2002), in terms of the temporal relationships between actions and events (Eskelinen 2001), or in terms of sets of features in a taxonomic space, using clusters in this space to identify genres. (Aarseth et al. 2003) Our approach is to develop a game ontology, identifying the important structural elements of games and relationships between these elements. Our use of the term ontology is borrowed from computer science, and refers to the identification and (oftentimes formal) description of entities within a domain. Our ontology hierarchically organizes structural elements. The top level consists of five elements: interface, rules, goals, entities, and entity manipulation (described in more detail below). Often, the elements derive from common game terminology (e.g. level and boss), which we refine by organizing them into more abstract concepts or by breaking them into finer, more precise concepts. An ontology is different than a game taxonomy in that, rather than organizing games by their elements, it is the elements themselves that are organized. Our work is distinct from design rule and design pattern approaches in that we don’t offer imperative advice to designers. We don’t intend to describe rules for creating good games, but rather to identify the abstract commonalities and differences in design elements across a wide range of concrete examples, clarifying common terms such as "level", "game world", etc. Our approach is distinct from genre analyses and from related attempts to answer the question "what is a game." Rather than developing definitions that allow us to distinguish between games/non-games or between different types of games, we’re focusing on an analysis of design elements that cut across a wide range of games. Our goal is not to classify games according to their characteristics and/or mechanics (Lundgren and Bjork 2003), but to describe the design space of games. Our ontology purposefully abstracts the representational details of games. Issues of setting (e.g. medieval castle, spaceship), genre (e.g. horror, sci-fi), and the leveraging of representations from other media (e.g. player’s knowledge of the Star Wars universe) are all bracketed by our analysis. Because our goal is to characterize the game design space, such bracketing is necessary in order to achieve broad coverage without having to abstractly characterize notions of setting and genre. Thus, we avoid the Sisyphean task of building an abstract model of the whole of human culture. A deep reading of any one particular game will, of course, require an analysis of its representational conventions, allusions and connotations. Our ontology would help position the more formal or structural elements of the game within the game design space, while other methods and techniques would be required to unpack representational issues. The top level of the ontology consists of five elements: interface, rules, goals, entities, and entity manipulation. The interface is where the player and game meet, the mapping between the embodied reactions of the player and the manipulation of game entities. It refers to both how the player interacts with the game and how the game communicates to the player. The rules of a game define and constrain what can or can’t be done in a game; they lay down the framework, or model, within which the game shall take place. Rules regulate the development of the game and determine the basic interactions that can take place within it. Goals are the objectives or conditions that define success in the game. Entities are the objects within the game that the player manages, modifies or interacts with at some level. This definition is broader than "game tokens" (Costikyan 1994) since it also includes objects that are not controlled by the player. Finally, entity manipulation encompasses the alteration of the game made either by the player or by in-game entities. Entity manipulation thus refers to the actions or verbs that can be performed by the player and by in-game entities. Each ontology entry consists of a title or name, a few paragraphs of text describing the element, a number of strong and weak examples of games that embody the element, a parent element, potentially one or more child elements, and potentially one or more part elements (elements related by the part-of relation). The examples describe how the element is concretely reified in specific games. Because many of the elements capture family-resemblance concepts (Wittgenstein 1963), we include both strong and weak examples; the weak examples describe border cases of games that partially reify the element. The parent/child relationship captures the notion of subtype (subset); child elements are more specific or specialized concepts than the parent element. Finally, the part-of relation captures the notion of compound elements that are constructed out of other elements (parts). In summary, we present an ontology in which we identify abstract elements that each capture a range of concrete designs. Our ontology allows for generalizations across this range of concrete design choices as embodied in specific games. For example, when thinking about the concept of a "level" in a game it is possible to recognize and describe the commonalities and differences that a "level" has with regards to a "bonus level", "boss level", "wave", "mission" or "world". We hope our ontology, which currently consists of more than 150 elements, will be used as a tool to inform and guide the analysis of games as well as provide a framework for the discussion and exploration of the design space of games. References Aarseth, E., S. Smedstad and L. Sunnanå (2003). A multi-dimensional typology of games. Level Up: Digital Games Research Conference 2003, Utrecht, The Netherlands. Bjork, S., S. Lundgren and J. Holopainen (2003). Game Design Patterns. Level-Up: Digital Games Research Conference, Utrecht, The Netherlands. Carlquist, J. (2002). "Playing the Story: Computer Games as a Narrative Genre." Human IT 6(3): 7-53. Church, D. (1999). Formal Abstract Design Tools. Game Developer. Costikyan, G. (1994). I have no words & I must design. Interactive Fantasy. Eskelinen, M. (2001). "Towards Computer Game Studies." Proceedings of SIGGRAPH 2001, Art Gallery, Art and Culture Papers: 83-87. Fabricatore, C., M. Nussbaum and R. Rosas (2002). "Playability in Action Videogames: A Qualitative Design Model." Human Computer Interaction 17(4): 311-368. Falstein, N. (2004). "The 400 Project." 2004(Oct 29).http://www.theinspiracy.com/400_project.htm Jenkins, H. (2003). Game Design as Narrative Architecture. First Person: New Media as Story, Performance and Game. N. Wardrip-Fruin and P. Harrigan. Cambridge MA, The MIT Press. Kreimeier, B. (2002). "The Case for Game Design Patterns." (Oct 29, 2004).http://www.gamasutra.com/features/20020313/kreimeier_01.htm Kreimeier, B. (2003). "Game Design Methods: A 2003 Survey." (Oct 29, 2004).http://www.gamasutra.com/features/20030303/kreimeier_01.shtml Kücklich, J. (2003). "Perspectives of Computer Game Philology." Games Studies: The International Journal fo Computer Games Research 3(1). Lundgren, S. and S. Bjork (2003). Describing Computer-Augmented Games in Terms of Interaction. Technologies for Interactive Digital Storytelling and Entertainment (TIDSE), Darmstadt, Germany. Murray, J. H. (1997). Hamlet on the Holodeck: The Future of Narrative in Cyberspace. New York, The Free Press. Salen, K. and E. Zimmerman (2004). Rules of Play: Game Design Fundamentals. Cambridge, Massachusetts, The MIT Press. Wittgenstein, L. (1963). Philosophical Investigations. New York, The Macmillan Company
