Under CPLR 1001, a necessary party is a person who ought to be joined if complete relief can be accorded or who might be inequitably affected by a judgment.

• A. Ought to be joined so that complete relief can be accorded or might be inequitably affected
• B. Has only incidental interest not affecting relief
• C. Is an indispensable witness
• D. Is a party with no interest

Answer: (A)

In NY civil procedure, a necessary party is someone whose involvement is required for the court to grant full relief or to protect that person’s interests from being harmed by the judgment. CPLR 1001 says you should join a person who, if left out, would either prevent the court from providing complete relief among the parties already in the case or would leave that person’s interests unfairly burdened by the outcome of the case. The phrasing that matches this is the one describing a party who ought to be joined so that complete relief can be accorded or might be inequitably affected by the judgment. For example, in a dispute over property with multiple owners, you can’t properly resolve the case without all owners in court, else one owner could be unfairly affected. The other options describe roles that don’t trigger joinder—such as a person with only incidental interest, an indispensable witness, or someone with no interest—so they don’t fit the concept of a necessary party.