A defendant in a negligence suit typically tries to negate one of the elements of the plaintiff’s cause of action. In other words, the defendant introduces evidence, for example, that he or she did not owe a duty to the plaintiff, exercised reasonable care, did not cause the plaintiff’s damages, and so forth. In addition to negating one or more of these elements, a defendant may rely on one of a few doctrines that may eliminate or limit liability based on alleged negligence. Two of the more common doctrines are comparative fault and assumption of the risk.