One of the key questions in the literature on defensive harm concerns the conditions under which a person is liable. It is helpful to distinguish two areas of debate. The first focuses on the relevance (if any) of facts about individuals’ agency, such as their beliefs, evidence, intentions, culpability, and degree of moral responsibility. The second focuses on the relevance (if any) of causal relations between an individual and a threat of harm. In this sub-section, we will canvass some of the main positions on the agential conditions of liability. For ease of exposition, we will focus on causally straightforward cases, in which an individual poses a direct threat to others. We will consider the causation debate in §1.3.