This chapter argues that the emergence of a common law of international adjudication has significant practical and theoretical implications. It then considers whether the common law of international adjudication can inform the response of international courts to issues which arise as a result of proliferation. In this regard, the chapter examines whether international courts have a power to dismiss proceedings summarily, either for manifest lack of jurisdiction, or abuse of process; the power to suspend proceedings; and the power to enjoin parties from pursuing parallel proceedings. The chapter then turns to the theoretical implications of the common law of international adjudication, and suggests that international courts do not regard themselves as ‘self-contained systems’, but rather as forming part of a community whose procedures and remedies have much in common. This evidences the existence of systemic features in international adjudication.