Johan Jeuring, Raja Lala, Jordy van Dortmont, Marcell van Geest

Many of the RAGE games make use of dialogues at some point. In the sports team manager game, a player selects a team consisting of virtual characters after having a conversation with these characters. In the interview simulation for job seekers game, a player first has to talk to a personal advisor virtual character, and after that this player potentially goes through a number of interviews with employers. In the interview skills for police officers game, a player plays a police officer who interviews a victim, for example a serious sexual crime victim. Finally, in the water cooler game, a player talks to fellow team members played by virtual characters, to practice social skills.

In essence, a dialogue in a game consists of a sequence of sentences between a player and one or more virtual characters. In most games a player chooses between several predefined options, but some games use spoken sentences as input, which needs speech-to-text processing and advanced methods for interpreting natural language(s). Another technique to generate a scenario is by using a virtual agent, which is an autonomous entity in a virtual environment. The challenge in using a virtual agent is achieving realistic simulations in which the degrees of freedom are suitable. In this blogpost we take a look at predefined scenarios that do not make use of spoken input, nor of virtual agents.

Even in scripted scenarios, there is a lot of variability in the dialogue forms in the RAGE games mentioned above. A player choice may lead to a numerical score, or to a score on a particular learning goal. Some games want to provide textual feedback on a choice of a player, other games only show feedback implicitly through a score. Most games use a single virtual character, but in one game a player talks with a team of virtual characters. Virtual characters can often display emotions. Sometimes we want these emotions to be displayed until a player makes a next choice, sometimes we want to play an animation of an emotion, and return to a more neutral state after that. The amount of variability in scenarios is substantial.

How do we support the various forms of scenarios in our authoring tool, the scenario editor? We developed an approach to configure our editor to make it possible to support various forms of scenarios. A scenario has several properties: static information that does not change for a scenario. Examples are the location in which a scenario is set, the name of a virtual character(s), or whether or not emotions go back to neutral before the next choice of the player. Besides properties, a scenario has parameters: dynamic information that can change at each statement in the scenario. Examples are a score on a learning goal, and the emotions of the virtual character (angry, happy, sad, etc.). Configuring an instance of the scenario editor for a particular game consists of specifying which properties are available, and what values they can take; which parameters are available, and what values they can take, in addition to a number of more administrative components.

We have developed a format (an XML schema) in which a game developer can specify a configuration necessary for an instance of the editor relevant to a game. In this editor, only scenarios of a particular format can be developed. Thus a game developer can guarantee that a scenario developed in the configured editor follows the desired format.

The possibility to support various formats of scenarios for games is essential for our scenario editor. Besides existing features that supports variability, such as interleaving in subjects, jump-points, possible pre-emptive endings, the kind of configurability discussed in this post adds another level of variability, which makes our scenario editor useful for many kinds of games.

The possibility to support various formats of scenarios for games is essential for our scenario editor. Besides existing features that support variability, such as choice, the scenario editor provides scenario dialogue writers with facilities to interleave subjects, make subjects optional and let the player choose to end a subject preemptively. The kind of configurability discussed in this post adds another level of variability, which makes our scenario editor useful for many kinds of games and nonlinear narrative on multiple levels.

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