What is an example of an affirmative defense?

An affirmative defense is a legal defense that, if established, negates or mitigates liability even if the allegations in the complaint are true. The assertion that the statute of limitations has expired is a clear example of an affirmative defense. This defense operates under the principle that a plaintiff cannot bring a lawsuit if they waited too long to file, regardless of the merits of their case. In essence, it acknowledges that the plaintiff may have valid claims but indicates that those claims are no longer actionable because they were not filed within the legally permitted time frame.

In contrast, denying the allegations in the complaint doesn't acknowledge the claims made against the defendant but simply contests their truthfulness. Claiming self-defense may be a valid defense in some situations, particularly in criminal law, but it does not fit the traditional framework of an affirmative defense unless it's brought forward alongside other defenses. Submitting evidence to refute the plaintiff's claims serves to counter the plaintiff's arguments rather than providing an independent basis for avoiding liability. Thus, each of these other options does not meet the criteria for being classified as an affirmative defense in the same way that asserting the expiration of the statute of limitations does.