Affirmative defense

An affirmative defense is a category of defense used in litigation between private parties in common law jurisdictions or a type of defense raised in criminal law by the defendant. Affirmative defenses can be classified as either a justification defense or an excuse defense. Affirmative defenses operate to limit, excuse or avoid a defendant's civil liability or criminal culpability, even though the factual allegations of the plaintiff's claim are admitted or proven. In fact, the defendant usually must affirm that the facts asserted by the plaintiff are correct in asserting his own defense; hence, "affirmative" defenses.