Res Judicata is the Latin term for “a thing adjudged.” In the legal community, it is used to refer to a matter already settled in court and cannot be raised again. For example, a case considered res judicata in Chicago can no longer be appealed or retried in Colorado, or any other court for that matter. The system is designed in such a way that it allows for the prevention of cases being tried repetitively, thus cluttering or clogging the legal system which may then lead to the exhaustion of vast amounts of money. Therefore, one of the many reasons why res judicata is important is because it ensures that people cannot be taken to court over and over again for the same thing. It also minimizes the risk of having conflicting verdicts, or court cases that tend to drag over a long course of years.
Res judicata allows judges to dispose of or disregard cases, which have already been tried and judged. However, there are therefore a number of criteria, which are considered before a judge decides to invoke res judicata. As an overall rule, it has to be established that a verdict in the exact same case has already been obtained in a court of competent jurisdiction.
Claim preclusion (true res judicata) is the valid and final judgment on a claim that precludes a second action on that claim or any part of it. There are four factors to consider in determining whether a plea of claim preclusion is valid: (1) Was the claim decided in the prior suit the same claim being presented in the action in question?; (2) Was there a final judgment on the merits?; (3) Was the party against whom the plea was asserted a party or in privity with a party to the prior suit?; (4) Was the party against whom the plea was asserted given a fair opportunity to be heard on the issue?
The concept of res judicata is handled slightly differently in the different legal systems. In civil law, cases must be fundamentally identical before they can be rejected on the basis of res judicata, while in common law, cases merely need to bear a substantial number of similarities.