A person or entity who is not a party to a lawsuit generally may intervene in the lawsuit and become a party to it by filing a plea in intervention prior to the entry of the court’s judgment—provided the court does not reject (strike) the intervention. An intervenor is not required to secure the court’s permission to intervene, and the party who opposed the intervention has the burden to challenge it by filing a motion to strike.

A person or entity has a right to intervene if the intervenor could have brought the same lawsuit, or any part of it in his own name—or, if the action had been brought against him, he would be able to defeat the lawsuit, or some part of it.

A trial court abuses its discretion by striking an intervention if (1) the intervenor meets the above test, (2) the intervention will not complicate the case by an excessive multiplication of the issues, and (3) the intervention is almost essential to effectively protect the intervenor’s interest.

In Kentucky, the rules regarding intervention in a lawsuit are governed by the Kentucky Rules of Civil Procedure (CR). Specifically, CR 24 outlines the conditions under which a non-party may intervene in an ongoing lawsuit. A person or entity may intervene as a matter of right if their interest is such that disposing of the action may as a practical matter impair or impede their ability to protect that interest, or if the existing parties do not adequately represent that interest. This is consistent with the description provided, where an intervenor could have initiated the same lawsuit or would have a defense against it. The intervenor is not required to obtain permission to intervene but must file a timely motion. If a party opposes the intervention, they bear the burden of challenging it by filing a motion to strike. A court may be found to have abused its discretion if it strikes an intervention that meets the criteria of having a significant protectable interest, not complicating the case excessively, and being nearly essential for protecting the intervenor's interests. It's important to note that while Kentucky law provides a framework for intervention, the specifics of each case can affect the application of these rules, and an attorney can provide guidance on the likelihood of successful intervention based on the unique circumstances of the case.