What is the effect of compulsory joinder as it relates to parties?

• A. All necessary and indispensable parties who could be affected by the outcome must be joined.
• B. Joinder is optional and may be disregarded.
• C. Only plaintiffs can invoke compulsory joinder.
• D. Jurisdiction is transferred to another court.

Answer: (A)

Compulsory joinder means the case must include every party whose interest could be affected by the outcome. Under Rule 19, those who are necessary or indispensable to the action must be joined if feasible, so the court can grant complete relief and avoid prejudice or multiple suits. If such a party can be joined, they must be brought into the action; if they cannot be joined, the court must decide whether the case can proceed among the existing parties or must be dismissed. This is why the correct answer states that all necessary and indispensable parties who could be affected by the outcome must be joined.