Contributory negligence is a common law tort rule (created by judges in court opinions, judicial decisions, or case law) that bars or prevents a plaintiff from recovering on a claim for negligence if the plaintiff contributed to the cause of the accident (was contributorily negligent) in any way. This rule may be referred to as pure comparative negligence.

Some states still apply the contributory negligence rule. But because of the harsh outcome of the contributory negligence rule, many state legislatures have enacted statutes that provide for comparative negligence or fault and reduce the plaintiff’s recovery by the amount of the plaintiff’s negligence or fault. This rule may be referred to as pure comparative fault.

Other states have enacted a modified comparative fault statute or law that reduces a plaintiff’s recovery by the plaintiff’s percentage of fault, but bars a plaintiff from any recovery if the plaintiff is 50% or more at fault for the cause of the accident.

And in South Dakota, the comparative fault system uses a slight/gross negligence system and only analyzes the comparative fault if the plaintiff’s negligence is slight and the defendant’s negligence is gross. Under this slight/gross negligence system, if the plaintiff’s negligence is more than slight and the defendant’s negligence is less than gross, the plaintiff is barred or prohibited from any recovery.

These contributory negligence and comparative fault laws vary from state to state and may change or evolve at any time—whether they are located in court opinions or in statutes.

In Delaware, the doctrine of contributory negligence has been replaced by the principle of comparative negligence. Under Delaware law, specifically Delaware Code Title 10, Section 8132, if a plaintiff is found to be partially at fault for an accident, their recovery is not completely barred. Instead, the plaintiff's damages are reduced in proportion to their degree of fault. However, if the plaintiff's negligence is equal to or greater than the combined negligence of all defendants, the plaintiff is barred from recovering damages. This system is known as modified comparative negligence. Delaware's approach allows plaintiffs to recover damages as long as their fault does not reach the 50% threshold. It is important to note that these laws are subject to change and should be reviewed for the most current information.