Section I of this publication briefly sets out the historic background of ISDS, and then identifies the salient features of the system and the main criticisms of it. Section II undertakes a review of treaty practice with respect to individual ISDS issues, such as consent to arbitration, the scope of ISDS, available dispute settlement forums, frivolous claims, applicable substantive law, the role of States in the interpretative process, remedies, and many others. It seeks to identify the rationales for, and implications of, particular treaty approaches to individual issues, and also to examine how IIAs have responded to problems revealed by the arbitral practice of the past decade. Section III sets out a menu of policy options for IIA negotiators and takes a broader look at the current state of the ISDS system in order to highlight possible improvements and alternatives.