According to many contemporary accounts, although responsibility requires that agents’ actions be responsive to their reasons, it does not always require that agents be able to do otherwise in the particular situation in which they act. Some believe that the ability to act otherwise is a necessary condition of responsibility only when one performs a blameworthy action, whereas others, following Frankfurt, believe that the ability to act otherwise is never a condition of responsibility. However, there are many ways in which one can act for a reason, some of them are compatible with the agent’s responsibility, and some of them are not. The paper argues that only those agents who have the ability to act otherwise can act for or against some reason in a way that is compatible with their responsibility.