Indefinites face competition at two levels: Presupposition and content. The antipresupposition hypothesis predicts that they signal the opposite of familiarity, or uniqueness, namely, novelty, or non-uniqueness. At the level of descriptive content, they are pressured from two sides: definites expressing identity and another phrases expressing difference, and Gricean reasoning predicts that indefinites signal both difference and identity and are infelicitous when definites and another phrases are felicitous. However, occasionally a space opens between the and another, for a to fill. This (...) is in part due to conditions handicapping the or another semantically, in part to another’s phonological handicap. The division of labor between determiners in the field of difference and sameness is thus the result of an intricate competition. We model this competition in a version of game-theoretic pragmatics. (shrink)