Adaptive Mixed-Initiative Dialog Motivates a Game Player to Talk with an NPC

Abstract

In most role-playing games, a non-player character (NPC) tends to have the most initiative, i.e., developing conversation topics, on the dialog. Thus, the player tends to experience a unilateral impression, i.e., the feeling of that an NPC forces conversation topics on the player in spite of the player's willingness, and gradually loses his/her motivation to communicate with an NPC. In order to address this problem, this study proposes a dialog method whereby an NPC can adaptively switch the initiative by determining the player's willingness to talk/listen to the NPC. Based on the results of an evaluation experiment in which the participants talked with the NPC in the game scenario, it is suggested that the aspect of mixed-initiative in our proposed method could decrease the unilateral impression associated with the existing method that an NPC has the most initiative. Furthermore, the determination of the player's desire in our proposed method could further motivate players to talk to the NPC.