Res judicata is the generic term for a group of related concepts concerning the conclusive effects given final judgments. Within this general doctrine there are two principal categories: (1) claim preclusion—also known as res judicata; and (2) issue preclusion—also known as collateral estoppel.
These legal doctrines generally preclude litigants from relitigating claims and issues that were previously litigated to a final resolution or judgment.
In Texas, res judicata, or claim preclusion, prevents a party from relitigating a claim that has already been finally adjudicated by a competent court. Once a final judgment has been rendered, the same parties cannot pursue the same claim in a subsequent lawsuit. This doctrine ensures the finality of legal decisions and conserves judicial resources by avoiding redundant litigation. Similarly, issue preclusion, also known as collateral estoppel, bars the relitigation of specific issues that were actually litigated and essential to the judgment in a prior suit between the same parties. Under Texas law, for issue preclusion to apply, the issue in question must have been litigated in the first lawsuit and must have been necessary to support the judgment in that case. These principles are grounded in both Texas state statutes and case law, and they are fundamental to the state's civil litigation process.
