This paper attempts to establish that, and explain why, the practice of punishing offenders is in principle morally permissible. My account is a nonstandard version of the fair play view, according to which punishment 's permissibility derives from reciprocal obligations shared by members of a political community, understood as a mutually beneficial, cooperative venture. Most fair play views portray punishment as an appropriate means of removing the unfair advantage an offender gains relative to law-abiding members of the community. Such views (...) struggle, however, to provide a plausible account of this unfairly gained benefit. By contrast, on my account punishment 's permissibility follows more straightforwardly from the fair play view of political obligation: Specifically, the rule instituting punishment is itself among those rules with which members of the political community are obliged to comply. For criminal offenders, compliance requires submitting to the prospect of punishment. (shrink)