Reaching past the secrecy so often met in arbitration, this study explains clearly and fully the workings of the UNCITRAL Rules of Arbitral Procedure recommended for use in 1976 by the United Nations. Pulling together difficult to obtain sources from the Iran -United States Claims Tribunal, arbitrations under Chapter 11 of the North American Free Trade Agreement, and ad hoc arbitrations the Authors illuminate the shape the bare bones UNCITRAL Rules take in practice. The authors cogently critique that practice in the light of the negotiating history of the rules and solutions adopted by the other major private rules of arbitral procedure. To aid the specialist in the field, the practice of these various tribunals is also faithfully extracted and reproduced so that it may be argued in yet unforeseen procedural contexts. Rich both in its analysis and sources, this text is indispensable for the international arbitration field.The Authors have all served with the staff of the Iran -United States Claims Tribunal and served as arbitrators, counsel and judges with institutions ranging from the World Bank's International Centre for Settlement of Investment Disputes, to the European Court of Human Rights, and the United Nations.