Under current international law, victims of armed conflict have a right to reparation from the responsible parties. Political obstacles may, however, prevent victims from bringing reparation claims before domestic courts. For example, if the victims assert reparation claims before the court of a responsible party, they may reasonably fear discrimination if they were targeted in the armed conflict on ethnic, racial or religious grounds. They may also face real and significant legal and procedural obstacles at the domestic level, in the form of jurisdictional uncertainties, immunities, statutes of limitations, lack of sufficient evidence, or the absence of class or group actions. Giving effect to the right to reparation may in such cases only be practicable in an ad hoc mechanism of some sort. In fact, various precedents for such reparation mechanisms exist. Although reparation mechanisms may take many different forms, most need to address such common issues as who is eligible for reparation; what type of harm will be addressed; and what type of remedies are to be made available. The present chapter examines the common and basic principles which can be extracted by the comparative analysis of past and ongoing fifteen mechanisms.