Res judicata: The doctrine of res judicata

The doctrine of res judicata is one of the most important principles in the legal system. Translating from Latin to mean “a matter judged,” this concept ensures that legal disputes are resolved conclusively, preventing the same parties from relitigating the same issues. By barring repetitive lawsuits, res judicata upholds judicial efficiency, reduces costs, and promotes fairness. This article explores the meaning, components, and practical applications of res judicata in the courtroom. Res judicata includes two related concepts: claim preclusion and issue preclusion (also called collateral estoppel or issue estoppel), though sometimes res judicata is used more narrowly to mean only claim preclusion. Claim preclusion bars a suit from being brought again on an event which was the subject of a previous legal cause of action that has already been finally decided between the parties [5] or those in privity with a party. Issue preclusion bars the relitigation of issues of fact ... The doctrine of res judicata safeguards the final and binding effect of decisions in three ways. The doctrine precludes re-litigation of the same subject-matter within the same proceeding, e.g. after a partial decision (such as on jurisdiction) 1 or after the partial annulment of an award. 2 The doctrine precludes re-litigation of the same subject-matter between the same parties in follow-up proceedings in that duplicative claims are inadmissible (ne bis in idem). 3 If the subject-matter of ... Res judicata differs in that it restricts the re-trial of the entire civil matter, rather than just judicial decisions on small, yet important, issues within the original case. The difference between res judicata and collateral estoppel then becomes a question of whether the court is being asked to make a judgment on an issue, or on a claim.