This thesis examines the adaptations of international law to a globalized environment by exploring the direct regulation of collective non-state entities in binding international law. Through an examination of practice in multiple areas of international law (including the law of peace and security, law of the sea, international investment law, international humanitarian law, and international human rights law) and from the theoretical perspective of international law’s dynamic nature, the thesis challenges the continuing default conceptualization of binding international law as inter-state law, as well as the view of binding international law being principally inapplicable to collective non-state entities. The research traces the processes of ongoing normative change and demonstrates in technical legal detail that contemporary international law addresses rights and obligations directly to collective non-state entities without the interposition of any state much more extensively than the standard literature suggests. In order to explain the mechanism of such entities’ normative inclusion, the thesis develops the concept of the functional threshold and argues that it is the functionally critical collective non-state entities, i.e., entities perceived as indispensable for the attainment of a particular legal regime’s function, which have become addressees of direct rights and obligations under international law. The thesis not only intervenes in theoretical debates on the contemporary transformations of international legal ordering, but also aims to impact legal practice and policy, which currently struggle with effective regulation of collective non-state entities’ conduct.