Competence-competence and corruption have, for different reasons, been mainstays of international dispute resolution thought and practice for the longest time. In the last few years, their intersection has become increasingly important and problematic. These lectures seek to define the problem and to provide acceptable solutions where possible. They attempt to derive support from both a stringent dogmatic approach and pragmatic attention to real-life expectations and conduct. More so than in other areas of private international law, the intersection between the powers of the arbitrator and the illegality of the subject matter or the parties’ conduct poses a particular challenge. That challenge is to postulate proper solutions under the law, including principles of transnational or international law, to conduct which can take on a multiplicity of appearances owing to conflicting cultural understandings of what is and is not legal in commercial life. The statement that bribery and corruption offend transnational or international public policy does not relieve the arbitrator from the burden of scrutinizing that statement doctrinally and exploring its consequences in a period of ever-increasing globalization of economic activity and investment.