a. Various devices: Following is a brief checklist of devices by which multiple parties, or multiple claims, may be brought into the case. (In most Civil Procedure courses, and for our discussion here, the multi-claim and multi-party discussion focuses on the Federal Rules of Civil Procedure. Most states have roughly similar rules.)
b. Counterclaim: D may make a claim against P, by use of the counterclaim. See FRCP 13. Check whether the counterclaim is “permissive” or “compulsory.” (Also, remember that third parties, who are neither the original plaintiff nor the original defendant, may make a counterclaim.)
c. Joinder of claims: Once a party has made a claim against some other party, she may then make any other claim she wishes against that party. This is “joinder of claims.” See Rule 18(a).
d. Joinder of parties: Multiple parties may join their actions together. Check to see whether either “permissive joinder” or “compulsory joinder” is applicable. Also, remember that each of these two types of joinder can apply to either multiple plaintiffs or multiple defendants. See FRCP 19 and 20.
e. Class actions: Check whether a class action is available as a device to handle the claims of many similarly-situated plaintiffs, or claims against many similarly-situated defendants. See FRCP 23. Look for the possibility of a class action wherever there are 25 or more similarly-situated plaintiffs or similarly-situated defendants.
f. Intervention: A person who is not initially part of a lawsuit may be able to enter the suit on his own initiative, under the doctrine of intervention. See FRCP 24. Check whether the intervention is “of right” or “permissive.”
g. Interpleader: Where a party owes something to two or more other persons, but isn’t sure which, that party may want to use the device of interpleader to prevent being made to pay the same claim twice. After checking whether interpleader might be desirable, decide whether the stakeholder should use “statutory interpleader” or “Rule interpleader.” See 28 U.S.C. §1335 (statutory interpleader) and FRCP 22 (Rule interpleader).
h. Third-party practice (impleader): Anytime D has a potential claim against some third person who is not already in the lawsuit, by which that third person will be liable to D for some or all of P’s recovery against D, D should be able to “implead” the third person. (Example: Employee, while working for Employer, hits Victim with a company car. Victim sues Employer in diversity, under the doctrine of respondeat superior. Under traditional concepts of indemnity, Employer will be able to recover from Employee for any amount that Employer is forced to pay Victim. Therefore, Employer should “implead” Employee as a “third-party defendant” to the Victim-Employer action.) See FRCP 14(a). Once a third-party defendant is brought into the case, consider what other claims might now be available (e.g., a counterclaim by the third-party defendant against the third-party plaintiff, a cross-claim against some other third-party defendant, a counterclaim against the original plaintiff, etc.).