Often we speak as if international courts were a form of enforcement: we assume that once a legal regime acquires a court, it has teeth. Both within national and international legal systems, however, implementation of adjudicated decisions is itself an enforcement problem. Compliance is not always a straightforward or likely outcome. It is the product of an uncertain and at times lengthy process shaped by political and social dynamics. All the more so in the international realm, wherein courts still lack purse and sword, but are more loosely linked to the executive branches and other actors on which they ultimately depend for the efficacy of their judgments. This chapter explores when and how the rulings of international adjudicative bodies receive compliance. What do recent studies in social science and law reveal about when and how international courts achieve compliance, and what impact, in turn, does compliance " or its absence " have on international courts?