Narrative Improvisation: Simulating Game Master Choices

Any computer game with a strong story has difficulty balancing the tension between narrative and agency. Strong narrative usually results in weak agency, and strong agency can weaken narrative structure. Narrative improvisation, adapting the story based on player reactions, is a difficult task for a game designer. Narrative improvisation, however, is regularly practised by the human game masters (GMs) of tabletop roleplaying games. As the first stage of building a game master agent (GMA), this paper examines the moment in which GMs decide if and how to alter their storyline due to player action. GMs were interviewed to discover their reactions when players make unexpected choices. Ten themes emerged from analysis of the interviews, we examined these themes to determine the thought processes that took place in the GMs’ minds, and we represented the processes as flow charts. These decision charts are a first step in the construction of a GMA that could assist in the development of more responsive interactive narrative in computer games.