Actus reus, or the act requirement, is the first part of culpability in criminal law. (You will meet the second part, mens rea, in the next section.) In short, almost every crime must have an act, but defining that act can be tricky. Sometimes something that seems like an act isn’t an act; other times, something that does not seem like an act is one. These cases introduce you to the act requirement. Notice distinctions between voluntary and involuntary acts, and between conduct and the results of conduct. Consider why the court reaches the decision it does in each case, and what its decision says about its concept of blameworthiness.