In this paper, we argue that the legitimation of killing in war is not simply formed by adherence to certainlegal requirements that exist apart from and prior to war; instead, we suggest, the law of armed conflict initself cannot but operate through admitting certain materials onto the battlefield as distinctively legalmaterials. Using the theory of legal materiality, we show that the military uniform is a legal material thatmakes the legal matter of legitimate targeting intelligible to law. This process happens through the waysin which the uniform shapes the possibility of visual recognition and differentiation in order to makecertain bodies targetable and others not targetable. We refer to this visual recognition and differentiationas a domain of persuasion. We show that the historical, functional and visual attributes of the uniform, asa design artefact, produce a convincing domain of distinction for the attacking agent. Finally, we turn toinsurgency, arguing that the legal matter of targeting is shaped not only by the presence, use andmanipulation of this legal material but also by the absence of it.