What is the term for joining a claim that is non-essential but facilitates resolution?

The term that refers to joining a non-essential claim that can help facilitate the resolution of a case is permissive joinder. This concept allows parties to join claims, parties, or both together in a single lawsuit as long as certain criteria are met, primarily that the claims arise out of the same transaction or occurrence or share common questions of law or fact.

Permissive joinder is significant because it promotes judicial efficiency by enabling the court to resolve related disputes in one proceeding, rather than requiring separate lawsuits for each issue. This approach minimizes the risk of inconsistent verdicts and saves time and resources for both the parties and the court.

In contrast, compulsory joinder refers to situations where a party must be joined in a lawsuit because their absence would impede the court's ability to provide complete relief or would unfairly prejudice existing parties. The other terms listed—counterclaim admission and mandatory claim addition—are not recognized legal concepts in the same context and do not accurately capture the essence of joining non-essential claims that nonetheless facilitate resolution.