I suggest an account of desuetudo in game-theoretic terms. I argue that there is an asymmetry with consuetudo, because consuetudo cannot be fully captured by a game-theoretic analysis, while desuetudo, properly understood as a dynamic, diachronic process, can. A norm (not necessarily a consuetudo) ceases to exist because there’s no need anymore, in an interactive situation, to foster certain equilibria, even though the same norm which is going in desuetudo might not have emerged as a consuetudo. While (...) this kind of norm dynamics cannot explain all kinds of consuetudines, it can explain desuetudo, understood as a dynamic process ending with normative indifference, from a state which was normatively relevant. In this game-theoretic account the dynamicity is captured by the repeated occurence of the game, while desuetudo is the opposite process, in terms of normativity, with which a norm emerges (regardless of the fact whether the initial norm was a consuetudo or posited). (shrink)