Civilian immunity without the doctrine of double effect

Civilian Immunity ('Immunity') is the legal and moral protection that civilians enjoy against the effects of hostilities under the laws of armed conflict and according to the ethics of killing in war. Immunity specifies different permissibility conditions for directly targeting civilians on the one hand, and for harming civilians incidentally on the other hand. Immunity is standardly defended by appeal to the Doctrine of Double Effect (DDE). We show that Immunity's prohibitive stance towards targeting civilians directly, and its more permissive stance towards harming them incidentally, can be defended without appealing to the DDE if agents suffer from overconfidence. Overconfidence is a cognitive bias that affects agents who are required to make decisions in the presence of significant uncertainty.