— Also termed mandatory joinder. [Cases: Federal Civil Procedure 201.]
compulsory joinder
The necessary joinder of a party if either of the following is true: (1) in that party’s absence, those already involved in the lawsuit cannot receive complete relief; or (2) the absence of such a party, claiming an interest in the subject of an action, might either impair the protection of that interest or leave some other party subject to multiple or inconsistent obligations. Fed. R. Civ. P. 19(a).