Responsibility is a notion that is central to all legal systems. Its operation in international law, however, has been complicated by (inter alia) the complexity of the operative rules, as well as the intricate factual dynamics on which it is called upon to operate. Such complications often create confusion, mistrust and even accountability gaps in important areas. This article deals with one such area: responsibility for the conduct of United Nations (‘UN’) troops. It commences with an analysis of the notion of responsibility in international law before elaborating the factual dynamics underpinning the relevant legal discussion comprised, inter alia, of the troop contribution frameworks, command and control structures, and the execution of UN orders. The article will then proceed to its core issue: how responsibility for acts directly perpetrated by UN forces (in contrast to other forms of responsibility pertaining to, for instance, aiding and assisting or directing the acts of another) should be apportioned.