In modern terminology, collateral estoppel is also known as issue preclusion. Whichever name it is known as, collateral estoppel is a common law doctrine of estoppel that prevents an individual from filing litigation involving an issue that has already been settled by the courts. This form of estoppel is related to the criminal law concept of double jeopardy.
Once a court has decided an issue that is necessary to enact a judgment, that decision of the court precludes the issue from being litigated again on a different cause of action that involves a party which was involved in the first case. One of the underlying principles behind collateral estoppel is to prevent legal harassment and to prevent the abuse of judicial resources.
Collateral estoppel does not prevent the filing of an appeal of a decision, nor does it prevent a party from asking a judge to be allowed to make a revised decision or argument. In Federal court, judgments on appeal are given a preclusive effect. However, in the event a Federal decision is vacated, the preclusive effect of a judgment will fail.
Constitutional issues of due process problems are raised by collateral estoppel, especially when it is applied to a party which was not involved in the original suit that allowed the invocation of collateral estoppel in the first place. However, collateral estoppel in this case only applies to parties that have not actually litigated the issue under dispute unless the party in the case has legal privity to a party that previously litigated the issue.