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In Florida, the legal doctrine of contributory negligence has been replaced by a system of pure comparative negligence. Under Florida law, a plaintiff's recovery in a negligence case is reduced by the percentage of their own fault. This means that even if a plaintiff is found to be partially responsible for the accident or injury, they can still recover damages, but the amount will be diminished in proportion to their degree of fault. Unlike some states that bar recovery if the plaintiff's fault reaches a certain threshold (such as 50% or more), Florida allows a plaintiff to recover damages regardless of the extent of their own negligence, even if it is greater than the defendant's. This approach is codified in Florida Statutes Section 768.81, which outlines the comparative fault rule and its application in negligence cases.