This article describes several issues that might arise once the amendments to the Rome Statute on the crime of aggression enter into force. A first issue relates to the jurisdictional mechanism pertaining to the crime of aggression. A second issue revolves around the various liability modes arising from the crime of aggression. Since the crime of aggression is a ‘leadership crime’ several liability modes that exist within the ICC Statute seem not to apply to this crime, such as accessory liability. Accomplices or third States aiding or inciting another State to commit an act of aggression, might be immune from prosecution. A third issue touched upon concerns the implementation of the crime of aggression at anational level. The principle of universal jurisdiction may empower States to prosecute individuals responsible for international crimes in their national courts. Yet, this might result in complementarity problems with regard to the crime of aggression. This article examines the complementarity ‘test’ applied by the ICC in order to determine the admissibility of a case and its ramifications that might arise from the crime of aggression.