The rational choice model has long been the gold standard of economic theory. While this theory performs well in the simple situations typically presented in textbooks, the quality of performance of the rational choice model weakens as the situations calling for decision become more complex. At this point it is necessary to distinguish the abstract form a theory takes from the substantive context inside of which acCon occurs. Form is a universal quality, but form must be brought to bear in a variety of distinct substantive situations. Our concern in this paper lies in integrating substantive concerns regarding ambiguity and undecidability that oMen affect choice situations into the formal framework of rational choice theory, and to do so with an illustrative variety of choice situations where rational choice is formally valid but where that formality is incomplete all the same.