Attorney–client privilege is often invoked as a defence in international arbitration proceedings. Nevertheless, the participants often have very different expectations regarding the applicable privilege standard, as national attorney–client privilege laws vary widely between jurisdictions. This is complicated by the fact that institutional arbitration rules do not include provisions on the scope of attorney–client privilege, nor do they contain conflict-of-laws rules to determine the applicable national privilege standard. The determination of the applicable level of protection is rather left to the discretion of the arbitral tribunal. Drawing on interviews with more than thirty leading international arbitration practitioners and extensive academic research, this book provides guidance to arbitral tribunals regarding the determination of the applicable attorney–client privilege standard. It compares attorney–client privilege in key common and civil law jurisdictions, analyses precedent from previous tribunals, and finally sets out proposed changes to the legal framework governing this area.