What does "exclusion" refer to in the context of necessary parties in a lawsuit?

In the context of necessary parties in a lawsuit, "exclusion" refers to the inability to join a required party. When a party is deemed necessary, it means their presence is essential to the resolution of the dispute, often because their interests would be affected by the outcome of the case. If that necessary party cannot be joined for some reason, such as jurisdictional issues or lack of availability, the exclusion of that party can significantly impact the proceedings.

This concept highlights the importance of including all parties that have a stake in the matter to ensure that the case can be fairly adjudicated. Failure to include necessary parties can lead to incomplete relief or affect the rights of those absent from the lawsuit. Thus, distinguishing exclusion as it pertains to the inability to join a required party helps clarify the procedural dynamics in litigation involving multiple parties.