In well-functioning domestic legal systems, courts provide a mechanism through which commitments and obligations are enforced. A party that fails to honor its obligations can be brought before a court and sanctioned through seizure of person or property. The international arena also has courts or, to expand the category somewhat, tribunals. These institutions, however, lack the enforcement powers of domestic courts. How, then, do they work, and how might they work better or worse? The first objective of this Article is to establish that the role of the tribunal is to promote compliance with some underlying substantive legal rule. This simple yet often-overlooked point provides a metric by which to measure the effectiveness of tribunals. But a tribunal does not operate in isolation. The use of a tribunal is one way to resolve a dispute, but reliance on diplomacy and other traditional tools of international relations is another. Furthermore, even if a case is filed with a tribunal, there may be settlement prior to a ruling and, even if there is a ruling, the losing party may refuse to comply. Understanding international tribunals, therefore, requires consideration of the entire range of possible outcomes to a dispute, including those that do not involve formal litigation. The second goal of this Article is to develop a rational-choice model of dispute resolution and tribunals that takes this reality into account. The third goal is to explore, based on the above model, various features of international tribunals and identify those that increase effectiveness and those that reduce it. Finally, the Article applies the analysis to help us understand two prominent tribunals: the World Trade Organization’s Appellate Body and the United Nations Human Rights Committee.