This summary is not the rule. The rule text controls.
If someone files a counterclaim or cross-claim in a lawsuit, sometimes the people already involved in the case aren't enough to fully resolve that claim. Other people or businesses may need to be part of the case for the court to make a complete and fair decision.
When this happens, the court can order those additional people to be added to the case as defendants. This makes sure everyone who has a stake in the outcome is included, so the court can settle the whole dispute at once instead of leaving loose ends.
There's one condition though. The court can only add these new parties if it has legal authority over them, known as jurisdiction. This usually means the person or business has enough connection to the state or the case for the court to legally require them to participate.
