If someone has filed a lawsuit or a claim against you, you're allowed to file your own claim back against them, which is called a cross-complaint. You can do this if you think you have a cause of action against the person suing you. Additionally, you can file a claim against someone else related to the case, even if they are not currently involved, as long as your claim is related to the same situation or property dispute that started the original lawsuit.

This law says that when someone files a cross-complaint, they can include other people as either cross-complainants or cross-defendants, even if those people aren't already involved in the lawsuit. This is allowed as long as the law for adding parties in a separate lawsuit would permit it. Basically, it expands who can be part of the case if it makes sense under the rules for joining parties.

If someone files a cross-complaint, they can combine it with any other claims they have against the same people being sued, except for the person taking land under eminent domain, and it doesn’t matter if those people are already involved in the case.

This law section states that when someone files a cross-complaint, it needs to be submitted as its own separate document, not mixed in with other documents.

If someone files a complaint against you, you need to file any counterclaims against them at the same time you respond to their complaint. You can file other kinds of counterclaims before the trial date is set. If you want to file a counterclaim outside these time frames, you need the court's permission, which can be granted if it's fair and necessary.

This law is about how to officially deliver a cross-complaint, which is a new complaint filed within an ongoing case. If a party hasn't joined the case yet, they're served as if it's the start of a new lawsuit. If they're already part of the case, the complaint goes to their lawyer or directly to them if they're not using an attorney. This can be done the same way you'd serve a summons or as the law describes in a specific section about serving documents.

This section explains what happens when someone (a third-party plaintiff) who is being sued believes someone else should pay if they lose the case. They can file paperwork to bring that person (a third-party defendant) into the lawsuit. The third-party defendant, when responding, can submit an additional document to show any defenses the original defendant might have had. This document needs to be shared with both the third-party plaintiff and the original person who sued.

This law states that what used to be called a 'counterclaim' must now be filed as a 'cross-complaint' in legal proceedings. If a law mentions using a counterclaim, it should be understood as needing a cross-complaint instead. Even if you accidentally label something a counterclaim, it's still valid and will be treated as a cross-complaint.