People frequently reward and punish other people if they perceive them to be responsible for the implementation of events that they like or dislike. However, the determinants of such responsibility perceptions are not well understood within economics. In this paper, I propose a notion of causal responsibility as one determinant of responsibility perceptions. The notion attempts to objectively capture the causal importance of a person’s action for the implementation of an event when the implementation depends on the interaction of multiple persons and, potentially, moves of nature. I incorporate the notion in a framework of responsibility preferences and study its implication for behavior and equilibria in strategic settings. Finally, I show that the notion can explain experimentally elicited punishment and reward patterns in multi-agent situations that are not well-explained by existing social preference theories.