The broad meaning of the term res judicata covers all of the various possible binding effects of a judgment on subsequent litigation.It may be assumed that the need for finality of judgment is recognized by many, if not by all, systems of law. The present study, however, is directed to the examination of the rationale behind the doctrine of res judicata and the meaning of the identity of actions, as reflected in Anglo-American and Israeli law.Res judicata is evidently not one of the easy problems in jurisprudence as many have noted in the past. As to England and Israel in particular, one can hardly say it has been adequately explored.It should be pointed out that the discussion is focused on judgments in personan, as distinguished from judgments in rem or quasi in rem; it does not deal with criminal cases, nor with decisions of administrative tribunals.All three legal systems recognize two facets of res judicata. In spite of variations in terminology, these basic principles are usually held and understood identically.