Determining the individual criminal liability of the numerous individuals who are involved in
the perpetration of atrocity crimes, which are massive by nature, constitutes one of the most
relevant challenges that International Criminal Law (ICL) faces today. Thus, the analysis of the
modes of liability becomes of great importance. The differences among legal cultures have given
rise to various interpretations with regard to the modes of liability applied by the ICC and the ad
hoc tribunals. The interpretative differences do not only depend on the tribunal, but they may also
arise within the case law of the same tribunal. The present paper addresses the interpretative
fragmentation related to co-perpetration. The author assesses the case law of the ad hoc tribunals
and the ICC: whereas the first is based on the Joint Criminal Enterprise (JCE) doctrine, the second
relies on the theory of control over the crime. The debate among the Chambers of the ICC
concerning dolus eventualis – and its implications on the ‘common plan’ element of coperpetration
– deserves special attention. By analysing the existing case law, the author concludes
that the ICC’s approach should be followed and that dolus eventualis should be considered
included in Art. 30 of the Rome Statute (RS).