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Civil Procedure 2022

Former Adjudication: Claim and Issue Preclusion

Imagine you were sued for a tort or breach of contract and you—as the Defendant—won. What, if anything, stops your opponent from litigating the entire case anew? The answer comes in this unit on preclusion (sometimes called “prior adjudication”). You will learn about two doctrines: (1) res judicata, also known as claim preclusion, and (2) collateral estoppel, also known as issue preclusion. These two doctrines govern the binding effect of prior judgments on future litigation. The Supreme Court summarized the doctrines as follows:

“Res Judicata” is the term traditionally used to describe two discrete effects: (1) what we now call claim preclusion (a valid final adjudication of a claim precludes a second action on that claim or any part of it), . . . and (2) issue preclusion, long called “collateral estoppel” (an issue of fact or law, actually litigated and resolved by a valid final judgment, binds the parties in a subsequent action, whether on the same or a different claim) . . . .

Baker v. General Motors Corp., 522 U.S. 222, 233 n.5 (1998). Four general principles explain these doctrines. First, a party ordinarily gets only one chance to litigate a “claim.” Second, a party ordinarily gets only one opportunity to litigate a factual or a legal “issue.” Third, a party is entitled to at least one “full and fair” chance to litigate before being precluded. And finally, preclusion may be waived unless it is claimed early in litigation.

We will take each of the two doctrines in turn, adding more complexity as we go. While we will use a few illustrative cases, this unit is primarily taught through hypotheticals.


15.1 Claim Preclusion (aka “Res Judicata”), as its name suggests, prevents a litigant from re-litigating an entire claim. It is also sometimes helpfully referred to as the “rule against claim splitting,” which tells you something about its justification. These materials will take you through the federal system's five basic requirements of claim preclusion, illustrating them with cases or hypotheticals.


15.2 Issue Preclusion (aka “Collateral Estoppel”), as its name suggests will prevent a litigant from re-litigating an issue that was litigated in a prior case—when it can be successfully argued. In some instances, as we will discuss, this will, in fact, doom an entire claim even though that claim is not claim precluded.

The first part of this sub-section, called “basics,” focuses on cases where the parties in the first case and the parties in the case for which issue preclusion is being argued are the same. These materials will take you through the federal system's four basic requirements for issue preclusion, illustrating them with a case or hypotheticals.

The second part of this sub-section, called “mutuality,” adds additional rules for when a party against whom issue preclusion is sought (raising questions of due process), or by whom issue preclusion is sought (raising the doctrine of mutuality), was not a party to the original case.


Congratulations. Once we finish these materials, you are at the end of the planned course. If time remains (it rarely does!) I will provide additional materials to learn about class actions, Multidistrict Litigations (MDLs), or alternative dispute resolution.