Comparing Behaviour Tree and Hierarchical Task Network Planning Methods for their Impact on Player Experience

The AI in games has a large impact on the player's experience, but the large variety of available AI implementation methods makes it difficult to determine which one(s) to use in any particular project, and the differences in their impact on players are mostly unstudied. This paper presents a compar-ative study to analyse the effects of Behaviour Tree AI and Hierarchical Task Network Planning AI on players experiences. The study participants (players) were given two prototypes of a third-person shooter game, each utilising different AIs, to play and give feedback on. According to the results obtained, players did not notice any major differences between the two prototypes, leading us to believe that the Behaviour Tree AI may be a better solution in most cases, as it is easier to implement.