Coordination problems, problems in which each agent's expected utility depends upon what other agents do, pose a problem for act utilitarianism. When the agents are act utilitarians and know of each other that they are so, they seem unable to achieve optimal outcomes in certain coordination problems. I examine various ways the act utilitarian might attempt to solve this problem, where act utilitarianism is interpreted within the framework of subjective expected utility theory. In particular, a new method for computing expected utility,dynamic deliberation, deserves examination as a possible act utilitarian solution to coordination problems. I argue that even dynamic deliberation fails to give the act utilitarian what he needs in coordination problems, and that the failure of act utilitarianism for such problems suggests the need for an alternative theory of moral choice along rule utilitarian lines.