Last amended December 1, 2007 · Last verified June 30, 2026
In one sentenceRule 18 lets a party asserting a claim join as many claims as it has against an opposing party, whether or not the claims are related, and join contingent claims such as those that depend on a future judgment.
(a)In General. A party asserting a claim, counterclaim, crossclaim, or third-party claim may join, as independent or alternative claims, as many claims as it has against an opposing party.
(b)Joinder of Contingent Claims. A party may join two claims even though one of them is contingent on the disposition of the other; but the court may grant relief only in accordance with the parties' relative substantive rights. In particular, a plaintiff may state a claim for money and a claim to set aside a conveyance that is fraudulent as to that plaintiff, without first obtaining a judgment for the money.
End
Amendment History
(Amended February 28, 1966, effective July 1, 1966; March 2, 1987, effective August 1, 1987; April 30, 2007, effective December 1, 2007.)
Plain-English Summary
Rule 18 is generous about combining claims. A party bringing a claim — as a plaintiff, counterclaimant, crossclaimant, or third-party plaintiff — may join as many claims as it has against an opposing party, whether or not they are related to one another. Two unrelated disputes between the same two parties can ride in the same case.
The rule also allows joining contingent claims: a party may join two claims even though one depends on the outcome of the other, such as a claim to set aside a transfer that only matters if the party first wins a money judgment. Whether those joined claims are tried together is a separate question handled by Rule 42.
Frequently Asked Questions
Can you bring unrelated claims against the same defendant in one lawsuit?
Yes. Rule 18(a) lets a party join as many claims as it has against an opposing party, whether or not the claims are related.
Can you join a claim that depends on winning a different claim first?
Yes. Rule 18(b) allows joining a contingent claim — for example, a claim to set aside a transfer that only matters once the party has already won a money judgment on the underlying claim.
Source & verification. The rule text and amendment history are reproduced verbatim from the
official Federal Rules of Civil Procedure (Fed. R. Civ. P. 18), a public-domain work of the U.S. Government.
Prescribed by the United States Supreme Court under the Rules Enabling Act. The plain-English summary is original and written by us. Last verified June 30, 2026. ·
Official source
Also known as:FRCP 18Fed. R. Civ. P. 18joinder of claimsjoining multiple claims