Sexual violence during war varies in extent and takes distinct forms. In some conflicts, sexual violence is widespread, yet in other conflicts—including some cases of ethnic conflict—it is quite limited. In some conflicts, sexual violence takes the form of sexual slavery; in others, torture in detention. I document this variation, particularly its absence in some conflicts and on the part of some groups. In the conclusion, I explore the relationship between strategic choices on the part of armed group leadership, the norms of combatants, dynamics within small units, and the effectiveness of military discipline.