This chapter examines how the concept of authority relates to questions such as how law binds its subjects, and whether certain rules ought to be followed. This is important at all levels of rule-making, but particularly so in respect of domestic criminal law, because of the way in which criminal law requires individuals to adhere to a certain level of conduct. These restrictions, such as they are, have a direct impact on individual autonomy with the aim of protecting the vulnerable and securing society in respect of crimes against the person. Although it is acknowledged that criminal law regulates a variety of conduct, the focus here is on crimes against the person because of its relevance to much of the conduct proscribed under international criminal law.