 The focus of this entry is normative decision theory. That is, the main question of interest is what criteria an agent’s preference attitudes should satisfy in any generic circumstances. This amounts to a minimal account of rationality, one that sets aside more substantial questions about appropriate desires and reasonable beliefs, given the situation at hand. The key issue for a minimal account is the treatment of uncertainty. The orthodox normative decision theory, expected utility (EU) theory, essentially says that, in situations of uncertainty, one should prefer the option with greatest expected desirability or value. (Note that in this context, “desirability” and “value” should be understood as desirability/value according to the agent in question.) This simple maxim will be the focus of much of our discussion.