When is not acting an act? One of the most fraught distinctions in criminal law has been the act/omission distinction. For most people, punishing inaction in certain situations seems to flow naturally out of the sense of blameworthiness that underpins much of criminal law. However, defining the criminal act when it is not an act raises problems. As a general rule, there is no criminal liability for omissions. The following cases and readings consider the exceptions to this rule, whether they arise from statutorily created duties, special moral relationships, contractual relationships, or the voluntary assumption of responsibilities. As you will see, in some cases, criminalizing omissions likely tracks your moral intuitions. In others, you may feel more conflicted. Consider why different scenarios imply different levels of blameworthiness, but also what goals or behaviors society may seek to promote by assigning affirmative duties to act.