This paper focuses on the role of culpability in determining the degree of liability to defensive harm, and asks whether there are any restrictions on when culpability is relevant to liability. A natural first suggestion is that it is only relevant (or at least is significantly enhanced) when combined with an actual threat of harm in the situation in which defensive harm becomes salient as a means of protection. The paper begins by considering the question of whether two people are equally liable to defensive harm in a situation if both culpably intend to harm another, but due to circumstances outside the control of the two people only one has a chance of succeeding in causing harm. I argue that there is no difference in liability between the two. I then turn to a kind of slippery slope challenge that accepting this conclusion would lead to a vast over-inclusiveness in those liable to defensive harm, and consider a recent attempt at meeting it that requires that a person’s culpability can only affect liability if it concerns the very situation in which defensive harm is relevant. Finally, I put forward and assess a new way of meeting the challenge that appeals to a particular conception of culpability together with auxiliary theses concerning how culpability can decrease over time, among others.