During the diplomatic conference in Rome, some States argued that a document on elements of crimes was needed to provide greater certainty and clarity regarding the content of each crime. One delegation suggested making the elements binding on the judges of the ICC. However, the majority of States were concerned at the prospect of unduly restricting judicial discretion and felt that it would be unacceptable to make the elements binding. In particular it was pointed out that all the war crimes in the Statute are derived from existing instruments of international humanitarian law, which provide the necessary framework for interpretation of the law on the crimes and secure the principle of legality.

Nevertheless, the idea of a document outlining the elements of crimes was not completely rejected in Rome, and Art. 9 of the Statute reflects the compromise that was reached. It stipulates that the Elements of Crimes ‘shall assist the Court in the interpretation and application of articles 6 (genocide), 7 (crimes against humanity) and 8 (war crimes)’ and thus clearly indicates that the elements themselves are to be used as an interpretative aid and are not binding upon the judges. The elements must ‘be consistent with this Statute’ and it should be emphasised that consistency with the Statute must be determined by the Court. Article 9 appears to be the lex specialis with regard to Art.