Issue preclusion

Issue preclusion, also called collateral estoppel, is narrower than claim preclusion. Instead of barring an entire lawsuit, it bars relitigation of a particular issue that was already decided. The issue has to have been actually litigated, actually decided, and essential to the earlier judgment. Once those conditions are met, the same party cannot get a do-over on that issue in a later case, even if the later case involves a different claim. The doctrine saves courts and parties from rehashing the same factual or legal disputes over and over.