The basic principles and methods governing the settlement of international disputes today—particularly interstate disputes—are substantially the same as those that were identified and enshrined in the Charter of the United Nations in 1945. Parties to a dispute are under a duty to settle it in a peaceful way (Article 2, paragraph 3 of the UN Charter). While barred from resorting to armed force, the parties remain however, at least in principle, “masters” of the procedure for dispute settlement, and of the outcome. In the absence of a precise treaty obligation, they are free to decide the particular means of dispute settlement they prefer (Article 33 of the UN Charter). More broadly, any settlement will inevitably depend, directly or indirectly, on the agreement of the parties. Thus, the whole edifice of dispute settlement at the international level is characterized by an inherent tension between a legal duty to settle disputes in a peaceful way and the absence of any real compulsory mechanism that may render such obligation effective. Against this legal background, the notion of dispute settlement covers a great variety of different settlement devices. Such procedures can be distinguished one from the other on the basis of different criteria, such as whether they contemplate the intervention of a third party, whether the settlement is based on the application of rules of international law, or whether the final outcome of the procedure has a binding or nonbinding character. The classification of these different procedures; the identification of their respective merits and shortcomings, in absolute or comparative terms; their suitability in relation to different categories of disputes—these are all issues that have been traditionally the object of a vast body of literature. On a broader perspective, recent trends, which have brought some changes in the field of the international dispute settlement, have also attracted the attention of doctrine. These trends include the progressive institutionalization of the procedures, thanks also to the growing role of international organizations in this area, the multiplication of settlement mechanisms and the ensuing problem of the possible interaction or conflict between them, the creation of new courts and tribunals, and the rise of adjudication as a means of dispute settlement.