More generally, some worry that the responsibility account rests on too thin a notion of moral responsibility. According to this objection, merely engaging in a foreseeably risky activity, and having bizarre bad luck, is not morally significant enough to defeat the weighty constraint on killing (Lazar 2009; see also, Burri 2020). This point seems especially forceful in cases in which a person’s evidence is that she is required, rather than merely permitted, to use force (Christie 2015: 75; Tadros 2011: 232–234). To illustrate, consider a variation on Mistake in which Victim’s twin is a notorious child-killer, and thus Homeowner’s evidence is that Victim will murder her child unless she uses force. Parents are plausibly required to defend their children against prospective murderers. Of course, Victim is not, in fact, a child-killer. But in this case, it is not obvious that we can point to Homeowner’s moral gamble to explain why it is fair that she forfeits her right not to be harmed. Gambles are typically optional: it is the fact that gamblers choose to engage in them, even though they could have done otherwise, that makes it fair for gamblers to bear the costs when their gambles turn out badly. By contrast, it seems unfair that Homeowner forfeits her rights by doing what her evidence tells her she is morally required to do (for a contrary view, see Quong 2020: 52–54).