Collective responsibility proposes an additional legal framework to hold organised armed groups responsible for systematic sexual violence during non-international armed conflicts. Conflict-related sexual violence is often carried out in a manner which replicates a systematic and recurring pattern. Conflict situations generate an atmosphere of pressure, a breeding ground for the institutionalisation of group obedience where individual fighters morph into the system. The individual merely acts in accordance with the contra-norms and -values of the group. The required elements for collective responsibility are first, attribution and second, prohibition. For an act or omis-sion to be attributable, the non-state armed group must be organised and have legal personality. The author aims to contribute towards filling the lacuna regarding the collective responsibility of systematic violations of international humanitarian law. This article will focus on the circumstances justifying when conduct is attributable to an organised armed group.