This guidance document, commissioned by the United Nations Office for the Coordination of Humanitarian Affairs, sets out the basic rules of international law regulating humanitarian relief operations in situations of armed conflict. It focuses primarily on international humanitarian law, but also considers other areas of public international law that may be relevant to such operations, particularly international human rights law and the rules on state sovereignty, territorial integrity, and the responsibility of states and international organisations for internationally wrongful acts. This is without prejudice to rights and obligations that may arise from other applicable rules of public international law.