This Issue Brief, entitled "Engaging Nonstate Armed Groups on the Protection of Children: Towards Strategic Complementarity", is published by the Non-Governmental Organization Geneva Call in collaboration with the International Peace Institute. The Issue Brief provides an overview of the legal, political, and operational frameworks protecting children from the effects of armed conflict, notably from violations by nonstate armed groups. It explores some of the limitations of these frameworks and their mechanisms, and discusses ways to maximize the comparative advantages of different actors when engaging nonstate armed groups to improve the protection of children’s rights.