an optimal decision is a decision that leads to at least as good a known or expected outcome as all other available decision options. it is an important concept in decision theory. in order to compare the different decision outcomes, one commonly assigns a utility value to each of them. if there is uncertainty as to what the outcome will be, then under the von neumann–morgenstern axioms the optimal decision maximizes the expected utility (a probability–weighted average of utility over all possible outcomes of a decision).