A more thorough explanation:

A cross-claim is a legal claim made by one party against another party who is also involved in the same lawsuit.

For example, if two people are suing a third person for damages caused in a car accident, one of the plaintiffs may make a cross-claim against the other plaintiff for their share of the damages.

Cross-claims are governed by Rule 13 of the Federal Rules of Civil Procedure (FRCP). According to this rule, cross-claims are only allowed if they arise out of the same transaction or occurrence as the original claim.

For instance, if a defendant is being sued for breach of contract, they may make a cross-claim against the plaintiff for breach of the same contract.

Another example of a permissible cross-claim is a claim for indemnification. If a party is found liable for damages in the original claim, they may make a cross-claim against another party to recover some or all of the damages.

Overall, cross-claims are a way for parties involved in a lawsuit to resolve all of their legal disputes in one proceeding.