What can happen if a defendant fails to assert an affirmative defense in their initial answer?

When a defendant fails to assert an affirmative defense in their initial answer, they may be precluded from introducing evidence related to that defense later in the proceedings. This is because, under Louisiana civil procedure, affirmative defenses must be specifically pleaded in the answer. If a defendant neglects to raise an affirmative defense at the appropriate time, they cannot subsequently rely on that defense, which limits their ability to present that particular argument or supporting evidence in the case.

The rationale behind this rule is to promote fairness and efficiency in the legal process. It ensures that both parties are aware of the defenses that will be raised early in the litigation, allowing for a more focused and streamlined trial. The requirement to plead affirmative defenses discourages surprises at trial and allows for adequate preparation by both parties.

In contrast, the other options presented do not accurately reflect the consequences of failing to plead an affirmative defense. An affirmative defense cannot be considered valid merely because it exists; it must be raised in a timely manner to be actionable. Additionally, an unpleaded defense cannot be introduced at any point during the trial once the initial answer has been filed. Finally, the responsibility does not fall on the plaintiff to prove the absence of a defense that was not presented by the defendant; instead, it