What is an 'affirmative defense' in legal terms?

An 'affirmative defense' is a legal concept that refers to a type of defense strategy in which the defendant acknowledges the facts of the case but offers additional information or justification that, if proven true, would absolve them of legal liability. This means that the defendant accepts that the prosecution's claims might be accurate but argues that there are other circumstances or defenses that justify their actions or negate culpability.

Examples of affirmative defenses include self-defense, insanity, duress, and entrapment. Each of these defenses relies on the premise that if the defendant can establish the truth of these claims, they should not be held legally responsible for their actions, regardless of the prosecution's evidence.

In contrast to this, other options reflect different legal ideas. For instance, a defense that assumes the prosecution's claims are untrue focuses solely on disputing the evidence presented, without providing any additional context. A procedural defense aimed at delaying a trial does not address the merits of the case itself, and a claim that disputes charges without evidence lacks the necessary component of establishing an affirmative justification. Thus, the defining characteristic of an affirmative defense is that it incorporates a justification or excuse that, if substantiated, can lead to a favorable outcome for the defendant.