Starting with peaceful protests of people demanding democratic reforms and fundamental rights from the regime in Damascus, the Syria crisis developed into a full-fledged civil war causing largescale death, injury, and displacement. During the first year of the crisis, violence in Syria was marked by the brutal crackdown of regime forces on protesters. Confronted with a high degree of violence from state forces, opposition groups gradually organized politically and militarily. This article focuses on international legal obligations of armed opposition groups in the course of this crisis. Such obligations are clearly contained in international humanitarian law, and arguably also in international human rights law. In order to determine the app...