The International Criminal Court (the Court) in The Hague, in fulfilling its mandate to put an end to impunity for the perpetrators of the most serious international crimes of concern to the international community as a whole, is neither able nor intended to investigate all situations of crisis across the world. Selectivity is unavoidable for the operation of this international organization. However, the authority of the Prosecutor of the Court to select and prioritize a situation over other situations is not unfettered. This book studies the situation selection regime at the International Criminal Court. In doing so, it first clarifies the notion of situation under the constituent instrument of the Court, the Rome Statute. In addition to this conceptualization, through describing the situation selection process and criteria, the Court’s law, policies and practices in this regard are examined. Dealing with the misunderstanding of the Court’s selectivity, this book reads the situation selection regime from the lens of expressivism. This theory justifies the selectivity in the Court’s operation. The book is a resource for anyone who seeks more insight into the situation selection regime of the Court.