Rules of Civil Procedure  Civil Procedure Rule 20: Permissive joinder of parties

All persons may join in one action as plaintiffs if they assert any right to relief jointly, severally, or in the alternative, in respect of or arising out of the same transaction, occurrence, or series of transactions or occurrences and if any question of law or fact common to all these persons will arise in the action.

All persons may be joined in one action as defendants if there is asserted against them jointly, severally, or in the alternative, any right to relief in respect of or arising out of the same transaction, occurrence, or series of transactions or occurrences and if any question of law or fact common to all defendants will arise in the action. A plaintiff or defendant need not be interested in obtaining or defending against all the relief demanded. Judgment may be given for one or more of the plaintiffs according to their respective rights to relief, and against one or more of the defendants according to their respective liabilities, and the court may issue one or more executions and make such order relative to costs as may be necessary and proper. In any action in which persons not asserting any right to recover jointly join as plaintiffs, and in which the relief sought is not wholly equitable, the entry fee shall be an amount equal to the aggregate of the entry fees which would have been required had separate actions been brought.

The court may make such orders as will prevent a party from being embarrassed, delayed, or put to expense by the inclusion of a party against whom he asserts no claim and who asserts no claim against him, and may order separate trials or make other orders to prevent delay or prejudice.

(1973) Rule 20(a) is the same as Federal Rule 20(a) except for: (1) the deletion of a reference to admiralty law, and (2) the addition of a reference to executions and costs taken from G.L. c. 231, § 4A.

Rule 20(a) changes prior law slightly, G.L. c. 231, § 4A allowed joinder where the rights or liabilities arose out of the same transaction, occurrence, or series of transactions or occurrences. Rule 20(a) adds the requirement, taken from Federal Rule 20(a), that there be a common question of law or fact.

The principal difference between Rule 20(a) and the prior statute is that the latter applied solely to actions at law whereas the former applies to all claims for relief.

Joinder of parties under Rule 20(a) obviously does not affect the substantive rights of the parties involved. For example, Rule 20(a) permits the joinder of a master and his servant. This follows prior law, see Kabatchnick v. Hanover-Elm Building Corp., 331 Mass. 366, 369, 119 N.E.2d 169, 172-173 (1954), but does not however convert the several liability of the master into a joint tort liability with his servant. Id.

Just as the prejudicial operation of Rule 18 (Joinder of Claims and Remedies) can be avoided by the court (Rule 42(b)), so also can embarrassment, delay and expense to a party be avoided by the court, acting under Rule 20(b).