Abstract The doctrine of common criminal activities is considered as an example of criminal liability in international criminal law. This concept was discussed explicitly for the first time by the international appeal court of Yugoslavia (Tadic) in 1999. However, it had been emphasized for several times by international jurisprudence. It was then utilized as one of the most important and effective methods of suing by the mentioned court and other special courts. According to this concept, members who form a common plan are not only recognized responsible for the planed crime but also liable for all the crimes which are the normal and predictable consequences of that agreement. Common activities and specially the third category of these category which is called under the title of “broad common criminal activities” and leads to the responsibility for the normal and predictable consequences has been brought up as one of the controversial issues in international criminal law. This essay is going to examine and analyze the common criminal activities, triple classification of this concept, actus reus and mens rea of each category along with the emphasis on the third category of these activities and its criticism.