Adding variety in NPCs behaviour using emotional states and genetic algorithms: The GENIE project

In recent years we have been observing an increasing adoption of artificial intelligence in video games. With the increasing availability of powerful hardware and advanced algorithms, we can now scale up the quality of the AI available to every Non Playing Character (NPC). Despite this increased quality, every NPC can get predictable with time and game designers are struggling to provide variety in games where many NPCs are present. Designing a specific, and unique, AI for every NPC can be a very time and resource consuming task. In this paper we propose GENIE (Genes Driven Decision Tree) as a tool to support game designers in the creation of a wide variety of behaviours. With GENIE, it is possible to define an NPC behaviour in term of internal parameters representing its state.