This book explores the operation, role, and prospects of global lawmaking, and the implications of the design of customary international lawmaking on social change. Drawing on insights from various disciplines and historical contexts, it provides an explanatory and analytical framework for the question. It goes further, however, by critiquing conventional accounts of international lawmaking and developing an alternative framework centered on the four types of customary international law. It brings a fresh and unique approach; drawing on jurisprudential, legal history, and social scientific perspectives, which will be essential for all scholars in the field.