This book expounds the theory of international arbitration law. It explains in easily accessible terms all the fundamentals of arbitration, from separability of the arbitration agreement to competence-competence over procedural autonomy, finality of the award, and many other concepts. It does so with a focus on international arbitration law and jurisprudence in Switzerland, a global leader in the field. With a broader reach than a commentary of Chapter 12 of the Swiss Private International Law Act, the discussion contains numerous references to comparative law and its developments in addition to an extensive review of the practice of international tribunals. Written by two well-known specialists - Professor Kaufmann-Kohler being one of the leading arbitrators worldwide and Professor Rigozzi one of the foremost experts in sports arbitration - the work reflects many years of experience in managing arbitral proceedings involving commercial, investment, and sports disputes. This expertise is the basis for the solutions proposed to resolve the many practical issues that may arise in the course of an arbitration. It also informs the discussion of the arbitration rules addressed in the book, from the ICC Arbitration Rules to the Swiss Rules of International Arbitration, the CAS Code, and the UNCITRAL Rules. While the book covers commercial and sports arbitrations primarily, it also applies to investment arbitrations conducted under rules other than the ICSID framework.