The ICRC's published 'Interpretive Guidance on the Notion of Direct Participation' by civilians in hostilities contributes usefully to the debate but is flawed. It creates an imbalance between members of the armed forces on the one hand, who are targetable at all times, and members of organised armed groups who do not have a continuous combat function, and civilians who persistently participate in hostilities on the other, who are said to be protected during intervals between specific acts of hostility. This imbalance is exacerbated by assertions that there is a presumption at law that civilians are not directly participating, that to be DPH there must be a single causal step linking the civilian's activity with the hostilities, that voluntary human shields may not be direct participants and that periods of preparation for, deployment towards and return from acts of direct participation, during which a civilian is liable to lawful attack, must be interpreted restrictively. This article takes aspects of the interpretive guidance in turn, analysing them to determine their legal and practical acceptability. It concludes that states must consider the guidance with some caution before determining their own position on this vexed issue.