Civil Procedure
Joinder
Definition
Joinder refers to the procedural rules governing which parties and claims may be brought together in a single lawsuit. Permissive joinder of parties (Rule 20) allows plaintiffs or defendants to join if their claims arise from the same transaction or occurrence and share common questions of law or fact. Compulsory joinder (Rule 19) requires that necessary parties be joined if feasible. Compulsory counterclaims (Rule 13(a)) must be asserted if they arise from the same transaction, while permissive counterclaims may be raised at the party's option.
Example
Two plaintiffs injured in the same car accident sue the at-fault driver in a single lawsuit. Their claims arise from the same occurrence, making permissive joinder appropriate.