This is the introduction to three articles that resulted from the Symposium on Responsibility of International Organizations and of (Member) States organized by the Amsterdam Center for International Law (ACIL) under direction of Professors André Nollkaemper and Pieter Jan Kuijper in April 2009. The Symposium concentrated on those articles of the ILC draft articles on the Responsibility of International Organizations which are concerned with the responsibility of States for the unlawful acts of International Organizations as well as with the responsibility of International Organizations for unlawful acts of States, and in particular Member States. This introductory article seeks to place the articles relating to these issues in the context of the draft articles as a whole and of their predecessors, the draft articles on State Responsibility. Moreover, since the articles in question are based on the notion of a directly incurred responsibility on the part of the international organization or State concerned, rather than the classical conception of responsibility through attribution, they are also analyzed in the light of these two conceptions of responsibility. The issue of shared responsibility deserves special attention in this respect.