Joinder is the procedural process of combining claims or parties in one lawsuit when the rules allow it.
It can help related disputes be resolved together instead of in separate cases.
Why joinder matters
Joinder affects efficiency, fairness, court jurisdiction, litigation cost, and whether all necessary parties are before the court.
Improper or missing joinder can lead to motions, severance, dismissal, or separate proceedings.
Where joinder appears
Joinder appears in complaints, amended complaints, third-party complaints, multi-defendant cases, class actions, counterclaims, crossclaims, and procedural motions.
The rules may distinguish permissive joinder from required joinder.
How it differs from nearby terms
Joinder is the general process of adding claims or parties. A third-party complaint is one specific pleading that can bring a new party into a case.
An amended complaint may use joinder concepts when adding claims or parties.
Practical example
Several plaintiffs injured in the same bus crash sue the same company in one lawsuit. The court considers whether joinder rules allow the claims to proceed together.
Related Terms
Quick check
Question: Is joinder about combining claims or parties in one case?
Answer: Yes. It is the procedural process for adding related claims or parties.