There is an ongoing debate as to how to make the law of armed conflict (LOAC) and human rights law (HRsL) interoperable. The International Committee of the Red Cross’s (ICRC’s) Interpretive Guidance on the Notion of Direct Participation in Hostilities under International Humanitarian Law has complicated that process. This article seeks to explain why there is a problem and to propose possible solutions. It only deals with the specific issues of targeting and opening fire. It does not address the issue of detention. Before embarking on that examination, it is first necessary to identify a range of assumptions and assertions on which the analysis will be based. Certain distinctions within LOAC will then be explored, because of their impact on the rules on targeting. The article will then examine how the decision to open fire is analyzed under HRsL. Options available to make LOAC and HRsL interoperable will be considered before finally suggesting a solution.