A: When someone brings a lawsuit seeking compensation for their injuries, the person being sued oftentimes wants to bring a claim against that person. That is often known as a counterclaim.
Typically, these counterclaims go beyond what is known as an affirmative defense.
For example, when someone brings a lawsuit claiming they have been injured by a doctor, many times the attorney representing the doctor will claim that the patient caused and contributed to those injuries. That is often known as an affirmative defense.
However, a counterclaim seeks to sue the person who is bringing the lawsuit. There many different types of counterclaims that can be filed. Keep in mind that if a doctor who is being sued now brings a counterclaim, he must follow the same process and procedure for showing that his claim has merit. He must do that by bringing in and producing evidence to show that he is more likely right than wrong on that particular claim.
The person who has originally brought the lawsuit, known as the plaintiff, will then have to defend the counterclaim. Now the claims and allegations ping-pong back and forth. The doctor will then have the burden of proof to show that he has a valid and meritorious counterclaim, and the injured victim will then have to defend against that counterclaim.