Contributory negligence in common-law jurisdictions is generally a defense to a claim based on negligence, an action in tort. This principle is relevant to the determination of liability and is applicable when plaintiffs / claimants have, through their own negligence, contributed to the harm they suffered.ontributory negligence is generally a defense to a tort of negligence. The defense is not available if the tortfeasor 's conduct amounts to malicious or intentional wrongdoing, rather than to ordinary negligence.