Chapter 2 explores how Etienne Wenger’s theory of communities of practice translates to the context of international law and the concept of a special regime. According to Wenger, a community of practice is defined by the presence of three structural elements: there must be a mutual engagement of community members; community members must be engaged in a joint enterprise; and they must have a shared repertoire. Chapter 2 draws up the contours of a methodology that will help the classically trained legal scholar to justify propositions categorizing segments of the international legal system as special regimes, based on the idealist’s conception of a special regime. As the chapter demonstrates, the task needed to justify a suggestion that some subpart of the international legal system is a special regime is not significantly different from many investigations that classically trained legal scholars are already conducting, more or less as a matter of course.