A New Approach to Interactive Drama: From Intelligent Characters to an Intelligent Virtual Narrator

The limits of current forms of interactive drama have been now clearly identified: interactive character based stories are poorly interactive, the plot remaining nearly linear; interactive virtual worlds are poorly dramatic, with no plot at all; the role of the user is confuse. This paper will give guidelines on how those problems should be tackled, by putting Artificial Intelligence (AI) in the right place, within an interactive drama system. Our research aims, in the long term, at building deeply interactive drama, with advanced models of narration. Goal of this research We aims at building a new genre of artistic expression, called interactive drama. An interactive drama is a drama (a narrative where the story is told by directly showing actions to the audience) where audience can act upon some events in the story. In this research, we are especially interested in the interactive drama where the user acts as a character within the story. Interactive drama should combine the strong emotional involvement and identification of classical drama (movie, theatre) with the feeling of immersion proper to interactive experience (video games, virtual worlds). It is admitted that current forms of interactive drama are clearly limited (Stern 1998, Szilas 1999). The existing interactive dramas usually fall into one of the two following drawback: either the drama is not really interactive, in the sense that the plot itself remains mostly linear, -or the interactive system is not really dramatic, consisting of simulated worlds rather than stories Why is it so difficult to build truly interactive drama? First, most known and theorized lbrms of drama are typically non interactive. Bringing interactivity to theatre or movie deeply modifies the essence of these artistic forms, and it is difficult to transfer our knowledge on movie and theatre to interactive experience. Second, existing forms of interactive narrative, like face to face storytelling, are very different from what interactive drama on a computer could be. Third, the role of the user, evolving from a "being told" status to an "interactive with" status has not been clearly identified (Portugal 1999, Szilas 1999): how the whole drama could be consistent if the way the author designs his/her characters differs from the way the user behaves with the same characters, by controlling one of the characters? Thus, interactive drama is a completely new challenge. A new art is emerging, as movie was emerging one hundred years ago, and we are in the early stage consisting in inventing the tools necessary to design interactive drama. The precise goal of our research is to build such tools, as well as related design methods (scripting for interactive pieces). In the following section, we will describe the basis of the system we are currently building. Our previous paper (Szilas 1999) gives more details on the system. Then, the next two sections concern new findings proper to this paper: how the intelligence of a virtual narrator should almost replace the intelligence of characters, why adaptive narration is necessary to build effective interactive drama and how to implement his feature. Overview of the architecture and its