Significant practice has been accumulated on the right to reparation for victims of armed conflict, as a result of the work of international human rights mechanisms, domestic courts, and States undergoing transitional justice processes and setting up domestic reparation programmes. This chapter looks at some of that practice in a nuanced way. It considers the interplay on reparation’s issues taking place between international human rights mechanisms like the European Court of Human Rights and the Inter-American Court of Human Rights, and domestic reparation programmes such as those established in Colombia or Guatemala. This interplay is regulated by the principle of subsidiarity, a key principle of international law. This principle manifests itself in different ways in international adjudication, including on issues related to reparations as international human rights mechanisms, including the ECHR and the IACtHR, exercise deference to States in various ways. This interplay poses major challenges as through it the scope and reach of this right is defined, and the role of these bodies decided. This Chapter looks at actual practice by these tribunals, and how they could face that interplay without diminishing their role or the content of the right to reparation