(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.
Rule 18.Joinder of Claims
Group IV: Parties · Last amended 2017 · Last verified July 14, 2026
In one sentenceRule 18 lets a party pack every claim it has against an opposing party into one lawsuit, related or not, including a claim that only becomes live if another claim succeeds first.
Full Text of Rule 18
(b) JOINDER OF CONTINGENT CLAIMS. A party may join 2 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.
Comments
2017 Amendments:
Rule 18 has been amended consistent with the 2007 stylistic changes to Federal Rule of Civil Procedure 18.
Comment:
Identical to Federal Rule of Civil Procedure 18.
Plain-English Summary
Once a party has a proper claim against an opponent, Rule 18 lets it add every other claim it has against that same opponent to the same lawsuit — related or not, and whether pleaded as independent theories or as alternatives to each other. The rule reaches beyond the original plaintiff's Complaint: anyone asserting a counterclaim, crossclaim, or third-party claim gets the same latitude to join additional claims against the party on the other side of that particular dispute.
Rule 18(b) reaches a trickier situation: a party can join two claims even when one depends on how the other comes out. The court will still decide relief according to the parties' actual legal rights rather than treat the contingent claim as though it were already established. The rule gives its own example: a plaintiff can sue for money owed and, in the same case, ask the court to set aside a transfer of property made to put it out of the debtor's reach as fraudulent — without first winning a judgment on the money claim and then coming back to challenge the transfer.
Because Rule 18 tracks its federal counterpart closely, courts applying it can look to the well-developed body of federal case law construing the equivalent federal joinder rule for guidance on how far "as many claims as it has" reaches in practice.
Frequently Asked Questions
Can I bring unrelated claims against the same defendant in one lawsuit?
Yes. Rule 18(a) allows a party asserting a claim, counterclaim, crossclaim, or third-party claim to join as many claims as it has against an opposing party, whether or not those claims are related, and whether pleaded as independent or alternative theories.
What does it mean to join a claim that is "contingent" on another claim?
Rule 18(b) allows a party to join two claims even though one can only succeed if the other is resolved a certain way first. The court still grants relief consistent with the parties' actual substantive rights, rather than treating the contingent claim as automatically valid.
Can I ask the court to set aside a fraudulent transfer before I have won a judgment on the underlying debt?
Yes. Rule 18(b) specifically allows a plaintiff to join a claim for money owed with a claim to set aside a conveyance that is fraudulent as to that plaintiff, without first obtaining a judgment on the money claim.
Does Rule 18 apply to counterclaims and third-party claims, or only to a plaintiff's original Complaint?
It applies to all of them. Rule 18(a) covers a party asserting a claim, counterclaim, crossclaim, or third-party claim, so a defendant asserting a counterclaim can join additional claims against the plaintiff in the same way a plaintiff can.
Does joining many claims under Rule 18 change who can be sued in the same case?
No. Rule 18 governs which claims a party may combine against an opponent it is already suing or being sued by. Whether additional people can be added as parties in the first place is governed separately by Rule 20 and related joinder rules.
Source & verification. Rule text and official Comments are
reproduced verbatim from the District of Columbia Superior Court Rules of Civil
Procedure, adopted by the Superior Court of the District of Columbia. Last verified July 14, 2026.
· Official source
Also known as: dc joinder of claimscombining multiple claims same lawsuit dccontingent claim joinder dc superior courtfraudulent conveyance claim joinder dcdc civil rule 18