ABSTRACT
In terms of the Statutes of the ad hoc International Criminal Tribunals for Rwanda and Yugoslavia, the judges of the Tribunals are empowered to adopt and amend the Rules of Procedure and Evidence of the Tribunals. This article argues that this power infringes upon the principle of legality and threatens the independence of the judges. It is submitted that the power to amend rules, unaccompanied by review mechanisms or sufficient safeguards, exceeds the power the judges should legitimately have been granted. Legal certainty requires rules to be fixed, knowable and certain. An accused should be in a position to prepare a defence with knowledge of the rules that will be applied by the court. It is argued that the practice of frequent amendments at the Tribunals threatens legal certainty and shows little respect for the rights of the accused.