Religious activities of the Pomio Kivung people of Melanesia challenges a specific claim of Lawson & McCauley's (1990) theory of religious ritual, but does it challenge the general claim that religious rituals are underpinned by ordinary cognitive capacities? To further test the hypothesis that ordinary social cognition informs judgments of religious ritual efficacy, 64 American Protestant college students rated the likelihood of success of a number of fictitious rituals. The within-subjects manipulation was the manner in which a successful ritual was modified, either by negating the intentions of the ritual actor or by altering the ritual action. The between-subjects manipulation was the sort of religious system in which the rituals were to be performed: one with an all-knowing god ("Smart god") versus one with a fallible god ("Dumb god"). Participants judged performing the correct action as significantly more important for the success of rituals in the Dumb god condition than in the Smart god condition. In the Smart god condition, performing the correct action was rated significantly less important for the success of the rituals than having appropriate intentions while performing the ritual.