Interactive Narrative often involves dialogue with virtual dramatic characters. In this paper we compare two kinds of models of character style: one based on models derived from the Big Five theory personality, and the other derived from a corpus-based method applied to characters and films from the IMSDb archive. We apply these models to character utterances for a pilot narrative-based outdoor augmented reality game called Murder in the Arboretum . We use an objective quantitative metric to estimate the quality of a character model, with the aim of predicting model quality without perceptual experiments. We show that corpus-based character models derived from individual characters are often more detailed and specific than personality based models, but that there is a strong correlation between personality judgments of original character dialogue and personality judgments of utterances generated for Murder in the Arboretum that use the derived character models.

Pathfinding is important in many applications, including games, robotics and GPS itinerary planning. In games, most pathfinding methods rely on runtime search. Despite numerous enhancements introduced in recent years, runtime search has the disadvantage that, in bad cases, most parts of a map need to be explored, causing a time performance degradation. In this work we explore a significantly different approach to pathfinding, eliminating the need for runtime search. Optimal paths between all pairs of locations are pre-computed. Since straightforward ways to store pre-computed paths are prohibitively expensive even for maps of moderate size, pre-computed data are compressed, reducing the memory requirements dramatically. At runtime, pathfinding is very fast, as it requires visiting only the locations on an optimal path. In each location, a quick computation provides the next move along the optimal path. We demonstrate the effectiveness of this approach on Baldur's Gate game maps. The compression factor reaches two orders of magnitude, bringing the memory requirements down to reasonable values. Compared to A* search, the runtime speedup reaches and even exceeds two orders of magnitude. When averaged over paths of similar cost, the speedup reaches a value of 700 in our experiments.

This paper presents a search-based approach to generating game content that satisfies both gameplay requirements and user-expressed aesthetic criteria. Using evolutionary constraint satisfaction, we search for spaceships (for a space combat game) represented as compositional pattern-producing networks. While the gameplay requirements are satisfied by ad-hoc defined constraints, the aesthetic evaluation function can also be informed by human aesthetic judgement. This is achieved using indirect interactive evolution, where an evaluation function re-weights an array of aesthetic criteria based on the choices of a human player. Early results show that we can create aesthetically diverse and interesting spaceships while retaining in-game functionality.

Agency, being one's ability to perform an action and have some influence over the world, is fundamental to interactive entertainment. Although much of the games industry is concerned with providing more agency to its players, what seems to matter more is how much agency each player will actually perceive. In this paper, we present a computational model of this phenomena, based on the notion that the amount of agency that one perceives depends on how much they desire the outcomes that result from their decisions. Using a structure for high-agency stories that we designed specifically for this intent, we present the results of a 141-participant user study that tests our model's ability to select subsequent events in an original interactive story. Using a newly validated survey instrument for measuring both agency and fun, we found with a high degree of confidence that event sequences selected by our model result in players perceiving more agency than players who experience event sequences that our model does not recommend.

This demonstration describes ScriptEase II, a tool that allows game story authors to generate scripts that control objects in video games by manipulating high level story patterns and game objects. ScriptEase II can generate scripting code for any game engine for which a translator is written. Currently there are translators for Neverwinter Nights and real Pinball games.

Authoring interactive stories where the player is afforded a wide range of social interactions results in a very large space of possible social and story situations. The amount of effort required to individually author for each of these circumstances can quickly become intractable. The social AI system Comme il Faut (CiF) aims to reduce the burden on the author by providing a playable model of social interaction where the author provides reusable and recombinable representations of social norms and social interactions. Motivated through examples from an in-development video game, Prom Week, this paper provides a detailed description of the structures with which CiF represents social knowledge and how this knowledge is employed to simulate social interactions between characters.

Online multiplayer gaming has emerged as a popular form of entertainment. the course of a multiplayer game, playerinteractions may result in interesting emer- gent narratives that go unnoticed. Afterthought is a system that monitors player activity, recognizes instances of story elements in gameplay and renders cinematic highlights of the story-oriented game play, allowing players to view these emergent narratives after completing their gameplay session. This paper describes Afterthought’s implementation as well as an empirical human-subjects evaluation of the effectiveness of the cinematics that it creates.

Analogy-based Story Generation (ASG) is a relatively under-explored approach for story generation and computational narrative. In this paper, we present the SAM (Story Analogies through Mapping) algorithm as our attempt to expand the scope and complexity of stories generated by ASG. Comparing with existing work and our prior work, there are two main contributions of SAM: it employs 1) analogical reasoning both at the specific story content and general domain knowledge levels, and 2) temporal reasoning about the story (phase) structure in order to generate more complex stories. We illustrate SAM through a few example stories.

Playtesting is the primary process that allows a game designer to access game quality. Current playtesting methods are often intrusive to play, involves much manual labor, and might not even portray the player's true feedback. This paper aims to alleviate these shortcomings by presenting the position that state of the art artificial intelligence techniques can construct automated playtesting systems that supplement or even substitute this process to a certain extent. Several potential research directions are proposed in this theme. A work-in-progress report is also included to demonstrate the conceptual feasibility of the potentials of this research area.

We have developed a method for detecting real money traders (RMTers) to support the operators of massively multiplayer online role-playing games (MMORPGs). RMTers, who earn currency in the real world by selling properties in the virtual world, tend to form alliances and frequently exchange a huge volume of virtual currency within such a community. The proposed method exploits (1) the trading network, to identify the communities of characters, and (2) the volume of trades, to estimate the likelihood of communities and characters becoming engaged in real money trading. The results of an experiment using actual log data from a commercial MMORPG showed that using the trading network is more effective in detecting RMTers than conventional machine learning methods that assess individual character without referring to the trading network.