Running Head: Agents and Avatars in MMORPGs Responses to interactive game characters controlled by a computer versus other players

Computer and video games often requires that users, represented by characters (or avatars) on the screen, interact with other characters on the screen that either represent other real people or characters that are controlled by computer code running within the game (non player characters). The difference between game play with other avatars (player controlled characters) or agents (characters controlled by the computer) may influence the engagement a player experiences during play. This study investigated the effects of agency (avatar vs. agent) and the type of gaming activity (competition vs. cooperation) on physiological arousal and subjective evaluation of play. A 2 (Avatar, Agent) x 2 (Competition, Cooperation) within-subject experiment was conducted (N=32). The results demonstrated that agency changes game experiences. Players exhibited greater physiological arousal to otherwise identical interactions when other characters were introduced as an avatar rather than an agent. Furthermore, the co-player’s source of agency interacted with the type of gaming activity. In the Avatar condition, the type of activity did not influence the player’s ratings of valence or sense of presence. However, in the Agent condition, players reported significantly more negative valence and less presence when competing compared to cooperating. The results have implications for understanding how different forms of representation in virtual worlds and games will affect psychological responses in the contexts of entertainment, learning and the conduct of serious work.