This chapter highlights the relevance of coercion to both the existence and the function(s) of law. Julieta A. Rabanos argues that if law is seen as a tool or artefact, the fulfilment of its function(s) depends on both its existence and its possession of a certain property that enables the achievement of that end. Following that she shows how coercion can be understood as necessary for the existence of law by analysing two main arguments for coercion-dependent existence: that coercion is motivationally necessary to ensure conformity to the law, and that coercion is necessary to guarantee the existence of a community. Finally, even if this argument fails, she shows that coercion can nevertheless be understood as the particular property that law has to fulfil its function(s); especially those related to behaviour-guidance and coordination-solving.