Gameplay design patterns for believable non-player characters

Psychology, Pedagogy, and Assessment in Serious Games

Serious Games rely on interactive systems to provide an efficient communication medium between the tutor and the user. Designing and implementing such medium is a multi-disciplinary task that aims at an environment that engages the user in a learning activity. User engagement is significantly related to the users’ sense of immersion or his willingness to accept the reality proposed by a game environment. This is a very relevant research topic for Artificial Intelligence (AI), since it requires computational systems to generate believable behaviors that can promote the users’ willingness to enter and engage in the game environment. In order to do this, AI research has been relying on social sciences, in particular psychology and sociology models, to ground the creation of computational models for non-player characters that behave according to the users’ expectations. In this chapter, the authors present some of the most relevant NPC research contributions following this approach.

Journal For Virtual Worlds Research, 2017

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2006

Artificial Intelligence in games has historically focused on providing a challenging opponent for a player and narrative development. Scope exists to increase the fidelity of synthetic characters throughout the game to create a more immersive game play experience. This requires both visual and behavioural fidelity, and while graphics are nearing photorealism, synthetic characters' behaviour is still unrealistic. Non-verbal behaviour of synthetic characters has to date received little attention and so the scope and participants of nonverbal behaviour requires identification. We review the range of spatial and task scenarios relevant in a game context, then identify categories of non-verbal behaviour and go on to summarise their role in communication and propose their incorporation in the design of non-player characters. Finally we review how non-verbal behaviour of synthetic agents might increase immersion for a player and identify interaction techniques that might facilitate non-verbal communication with players and non-player characters alike.

Lecture Notes in Computer Science, 2014

Much of the current research into artificial intelligence (AI) for computer games has been focused on simple actions performed by the characters in games (such as moving between points or shooting at a target, and other simple strategic actions), or on the overarching structure of the game story. However, we claim that these two separate approaches need to be bridged in order to fully realize the potential of enjoyment in computer games. As such, we have explored the middle ground between the individual action and the story -the type of behavior that occurs in a "scene" within the game. To this end we have established a new model for that can be used to discover in what ways a nonplayer character acts in ways that break the player's feeling of immersion in the world.

2009

Game designers attempt to ignite affective, emotional responses from players via engineering game designs to incite definite user experiences. Theories of emotion state that definite emotional responses are individual, and caused by the individual interaction sequence or history. Engendering desired emotions in the audience of traditional audiovisual media is a considerable challenge; however it is potentially even more difficult to achieve the same goal for the audience of interactive entertainment, because a substantial degree of control rests in the hand of the end user rather than the designer. This paper presents a possible solution to the challenge of integrating the user in the design of interactive entertainment such as computer games by employing the "persona" framework introduced by Alan Cooper. This approach is already in use in interaction design. The method can be improved by complementing the traditional narrative description of personas with quantitative, data-oriented models of predicted patterns of user behaviour for a specific computer game Additionally, persona constructs can be applied both as design-oriented metaphors during the development of games, and as analytical lenses to existing games, e.g. for evaluation of patterns of player behaviour.

Proceedings of DiGRA Conference 2014, 2014

When game studies has tackled the player-character, it has tended to do so by means of an oppositon to the notion of the avatar, with the result that the ontological and semiotic nature of the character in itself has not been given due attention. This paper draws on understandings of character from the fields of narratology and literary theory to highlight the double-layered ontology of character as both a possible individual and as a semiotic construction. Uri Margolin’s narratological model of character signification is used as the basis for developing a semiotic-structural model of the player-character that addresses its specific medialities and formal nature – a task which is performed through illustrative close examinations of the player-characters in The Last of Us (Naughty Dog 2013) and Gone Home (The Fullbright Company 2013).

Business, Technological, and Social Dimensions of Computer Games Edited By: Maria Cruz-Cunha (Ed.) Vitor Hugo Varvalho (Ed.) Paula Tavares (Ed.). IGI, 2011

We address the problem of creating human-like, believable behavior for game characters. To achieve character believability in games, the game designer needs to develop that character so that it fulfills as many aspects of believability as possible. With believable behavior we mean that the game is consistently structured in terms of narration or gameplay so that it is possible to build and maintain coherent relations between the actions of the characters. In this paper, we first analyze the general patterns for game characters ...

Hispanics, and African Americans [2]. This trend has been observed in several markets, including Japan, China, Korea, and India, who has just published their first international AAA title (defined as high quality games with high budget), a 3D third person action game: Ghajini-The Game [3]. The topic of believable characters is becoming a central issue when designing and developing games for today's game industry. While narrative and character were considered secondary to game mechanics, games are currently evolving to integrate characters, narrative, and drama as part of their design. One can see this pattern through the emergence of games like Assassin's Creed (published by Ubisoft 2008), Hotel Dusk (published by Nintendo 2007), and Prince of Persia series (published by Ubisoft), which emphasized character and narrative as part of their design. Beyond the entertainment industry, the use of virtual environments for learning, health therapy, cultural awareness, and training is increasingly becoming a reality. In the recent years, there has been an increase in the number of research initiatives that use simulations and interactive 3D environments for a wide variety of applications [4-11]. Several great examples are displayed in the projects developed by Institute of Creative Technologies at University of Southern California, where they utilize 3D environments with rich characters to teach cultural norms and foreign language, among other subjects. These applications provide a safe and comfortable environment for participants to interact within and learn at their own pace. In order to achieve their goals, however, such applications require realistic simulation of culture, people, and space. Thus, again the topic of believable characters is gaining more attention as a central topic that deserves further attention.

This paper re-frames virtual interactive characters as " subjective interfaces " with the purpose of highlighting original affordances for interactive story-telling through conversation. This notion is theoretically unpacked in the perspectives of narratology, interaction design and game design. Existing and imagined scenarios are presented in which subjective interfaces are elevated as core interaction mechanics. Finally, technical challenges posed by this approach are reviewed alongside relevant existing research leads.

This thesis explores the phenomenon of character autonomy, which I define as situations where character complexity is prominent in one or more categories while avatar control is limited or non-existent. Avatar control describes the levels of the player’s control of the avatar in a specific instance under study, while character complexity refers to how characterisation is communicated in that instance. I argue that both concepts can be measured on a four-point scale, ranging from high/full character complexity/avatar control to no character complexity/avatar control. Using the two models, I define various types of character autonomy; cutscenes, forced dialogue, quick-time events, idle animations, unwillingness, and (other) unmotivated actions. These six types are discussed in relation to the concepts of avatar and character to uncover how the two are often interrelated and thus difficult to assess as separate. Various theories from game studies (Lankoski et al, 2003; Vella, 2015), literary studies (Margolin, 1986; Forster, 1985), and transmedia studies (Bertetti, 2014) are used to explore the notion of character in video games and discuss how the model of character complexity can function with the inherent connection between avatar and character. Moreover, I discuss the various approaches to the notions of avatar (Linderoth, 2005; Klevjer, 2007; Bayliss, 2007), player character (Westecott, 2009; Lankoski, 2011), and playable figure (Vella, 2015) to outline how various terminologies are used to make sense of the subject matter, and to critically engage in a discussion of what I refer to as the trinity between player, avatar, and character. The concept of character autonomy is studied through various examples, uncovering how this can easily be mistaken for what I term automated avatar actions and define as actions which are automatically performed by the avatar promoting the player’s focus on game mechanics. Such actions, as for example the act of walking, can be understood as limitations to the player’s agency and hence her avatar control, but have formal functions that are very different from character autonomy. When studied in comparison, the two phenomena illustrate how characters in video games cannot be productively studied as characters in non-ergodic media, as an avatar is in many games necessary for playerinteraction. The avatar may have its own functions and attributes, unrelated to the character it can represent, constituting a paradoxical relationship between the two, where they cannot be studied either in isolation or as one and the same thing. I conclude by arguing that this illustrates how some core concepts such as avatar and character are not sufficiently established to ground a theory of games. Being an interdisciplinary field, game studies, including this very thesis, builds on concepts and theories from other disciplines, especially that of narratology, and while much of this work is productive and relevant for the study of digital games, we must constantly ensure that such concepts are revised as medium-specific. If not, we may easily overlook some of the intrinsic and fundamental elements of the digital, ergodic medium.