International criminal law (ICL) is a body of international rules designed both to proscribe certain categories of conduct (war crimes, crimes against humanity, genocide, torture, aggression, international terrorism) and to make those persons who engage in such conduct criminally liable. These rules consequently either authorize states, or impose upon them the obligation to prosecute and punish such criminal conducts. This chapter discusses the main features of ICL; the sources of ICL; and the notion of international crimes.
