Do international courts matter and how would we know? Although international courts do not have the power to enforce their judgments, states still comply with court rulings a significant portion of the time -- why? I argue that international court judgments can affect states' motivation and capacity to comply. Specifically, institutions are able to effect behavioral change directly by clarifying legal obligations, which corrects non-compliance due to lack of understanding. Moreover, the institutions' effects can be indirect: court judgments create a focal point by which pro-compliance actors both within and outside of the state can pressure states to comply, and may also improve capacity for compliance by providing domestic political cover and by creating opportunities for interest groups to offer expertise. I test this theory using two original datasets on cases before the Inter-American Commission and Court of Human Rights. I leverage the variation in degree of difficulty of specific compliance orders (e.g., publish the judgment, pay monetary reparations) to identify the impact of international institutions on state behavior, and ultimately to assess the effectiveness of the institutions themselves.