Achieving cooperation between individuals is challenging and often driven by self.-beneficial motives. On the other hand people also seem capable of subordinating ther personal imerests and of engaging in cooperation for motives other than their own, i.e. out of altruistic impulses. One context in which both motivational facets can be observecl is multiplayer online games. However, there is a lack of knowledge about how cooperation based on altruism and egoism develops in games, which al.so prevents us from transferring this knowledge as a form of gamification. In this study, we explore which game features are accountable for altruistic ancl egoistic sentiment. and how these distinctive demeanolJ"s inclu:e cooperation in games, with the intent to also derive implications fa gamification We employ we-intention and I-iitention theory and conduct a survey among pla)'Ors of the game Ingress (N= 206). Ou- findings imply that (1) cooperative game design can give rise to within-group altruism in form of enjoyment in helping others and cooperative goals, (2) altruism can lead to the formation of we-intentions, and (3) individualistic game features invoke Hntentions and self-centered motivations in games in the form of recognition-seekiig. Theoretical and practical implications are provided fa cooperative ga rre and gamification design.