This chapter addresses core theoretical issues surrounding global/transnational legal pluralism, taking up the work of leading theorists. First, is demonstrates that global legal pluralism is very different from earlier versions of legal pluralism (postcolonial and sociological). Next, is exposes the flaw of overinclusive conceptions of legal pluralism, which appears in the global legal pluralism of Paul Berman, and it explains why theoretical concepts of law cannot solve this flaw. It then addresses the profusion of private and hybrid regulatory forms on the domestic and transnational levels, and marks the line between theory and practice. Thereafter, it exposes problems with the relational concept of law formulated for global legal pluralism by Ralf Michaels, showing why it is unsuitable for many situations of legal pluralism. The approach to transnational legal pluralism the chapter articulates avoids these conceptual problems. It centres on conventionally identified forms of law that vary and change over time, which can be grouped in terms of three categories: community law, regime law and cross-polity law. Finally, it sets forth a handful of specific lessons for a reconstructed transnational legal pluralism.