We examined performance schemata in dyadic competitive and cooperative situations, that is, the ways people perceive the relationship between performance level, capacity level, and degree of motivation in situations in which two people confront or collaborate with one another. In Experiment 1, 104 participants judged the possible performance of Person A, whose ability and motivation levels were communicated, competing against Person B, whose ability and motivation levels were also communicated. When judging A’s performance, participants seemed first to assess the difficulty of the task facing A and second to integrate information relative to A according to a rule with changing parameters already proposed by Surber (1981a, 1981b). In Experiment 2, 140 participants judged either the possible performance of Person A in a cooperative situation or the possible performance of the A–B team using the same material. Results showed that people judge A’s performance or the team’s performance using a very simple additive rule.