Res judicata (derived from "res iudicata", Latin for "a thing decided"), more commonly res judicata in legal usage, is a common law doctrine meant to bar relitigation of cases between the same parties in court. In other words, a rule of civil law that once a matter has been litigated and final judgment has been rendered by the trial court, the matter cannot be relitigated by the parties in the same court, or any other trial court. A court will use res judicata to deny reconsideration of a matter.