If it is permissible for Victim to break Villain’s leg, and only necessary defense is permissible, breaking Villain’s leg must be necessary. But (we assume) a broken leg is more harmful than a broken arm. How, then, can pushing Villain be necessary for saving Victim’s life, given Victim’s available alternative of jumping at the cost of breaking his own arm? One influential proposal (which we touched on in §3.1), is that harms to which a person is liable count for less than harms to which a person is not liable. Since Villain is liable to defensive harm, we can discount Villain’s interests relative to Victim’s interests (as well as the interests of any bystanders) (Lazar 2012:7; McMahan 2016:185). On this view, necessity requires defenders to use the defensive option which causes the least morally-discounted harm.