Since 1945, international criminal justice has been one continuous construction site, an expression of the attitude of international stakeholders and policymakers that favours temporary solutions to contemporary problems. Even with the creation of the ICC that has not really changed. This chapter will set out a few fundamental and rather radical ideas that aim at initiating a thorough rethinking of the way criminal proceedings at the international level are regulated and run today. It sees itself very much as a call for a principled re-evaluation and for a move away from the attempts of the last two decades of arriving at a genuine amalgam of diverse systems by the method of judicial trial and error. The existing model(s) is/are an exemplary expression of the temporariness of international law, because it/they proceed(s) from a refusal by international law-makers to engage in drafting a permanent model that retains fairness standards while striving for maximum efficiency and that is meant to be applied across the board to any (new) tribunal—an approach that would lead to much greater certainty of law than is currently the case because of an increase in cross-institutional comparability. The chapter contends that while both adversarial and judge-led systems in their own national settings can achieve comparable levels of fairness, they differ in efficiency and that a judge-led model is better suited for the international arena and should be made the foundation for any future permanent procedural framework. However, the temporary nature of the present system which mainly uses adversarial models is based to a large extent on an unprincipled reliance on supposedly ‘ready-made’ and ‘tried and tested’ solutions from as well as the experience of staff employed at previous tribunals. The use of the adversarial model is thus not based on a principled evaluation of its usefulness and effectiveness in the international context but on a default attitude of the lawyers creating and populating international tribunals, and possibly the diplomatic community in the wider sense.