Individual actors in genocide are often divided up into a trichotomy of perpetrators, victims, and bystanders. Such an approach may be misleading in understanding genocide, where actors often shift between roles, or take on multiple roles. This chapter seeks to understand the complexity of individual action in genocide through presenting an alternative framework based on individual positionality (the position of individuals in relation to genocide), and agency (the capacity for individuals to act independently). It argues that positionality and agency interact to form a margin of discretion—the perceived range of choices available to an individual. It draws from the author’s interviews with perpetrators and victims of genocide and mass atrocities in several countries to illuminate the margins of perpetration—where individuals perpetrate while also occupying other roles. Changing roles in genocide often involves risks and rewards, which evolve throughout a genocide, as well as in the post-genocide period.