Throughout its history, the Association of Southeast Asian Nations (ASEAN) has based decisions on consensus and consultation, producing a loosely defined, weak regional organization. The results of nonbinding and watered-down resolutions make substantial progress for ASEAN difficult. This article explores the logic of ASEAN's decision-making by applying rational choice theory. It argues that the characteristics of ASEAN's decision-making mechanism allow member states to base their actions on how individual nations perceive their interests to be best served by group resolutions. By constructing a series of hypotheses to pattern ASEAN's decision-making, this article examines four cases and how players resolved each. The findings suggest that the constraints of group decision-making and divergent interests between member states play a major role in shaping the effectiveness of resolutions.