The study of information about the possible commission of one of the several crimes of the International Criminal Court under the standard test called "reasonable basis to believe" becomes the definitive criterion for future decisions to open investigation by the Trial Chamber, based upon the preliminary examinations by the Office of the Prosecutor of the Court. This paper proposes the approach of the ICC and its functional dynamics on the stage of international criminal law. This will enrich the debates on how the Court decides to admit a situation as one that is within its competence.