Comparative negligence is a legal rule used when more than one party contributes to an injury. A court may assign each party a percentage of fault and reduce damages according to the injured person’s share of responsibility. States use different comparative fault systems, so the same percentage can produce different legal results.
What Is Comparative Negligence?
Comparative negligence applies to negligence claims involving shared responsibility.
Instead of viewing every accident as entirely one person’s fault, the legal system may compare the conduct of the parties involved.
The Legal Information Institute explains that comparative negligence reduces damages according to each party’s contribution to an incident.
A Simple Comparative Negligence Example
Consider a collision involving two drivers.
A fact finder determines that Driver A bears 70 percent of the responsibility. Driver B bears the remaining 30 percent.
Under a comparative negligence system that permits Driver B’s claim, Driver B’s damages may be reduced by the assigned 30 percent.
Why the Percentage Matters
The assigned percentage can directly affect the damages available under applicable law.
However, percentages do not operate the same way in every state.
Some jurisdictions permit damages even when the claimant carries most of the fault. Others apply a cutoff point.
Pure and Modified Comparative Negligence
Comparative negligence generally appears in two broad forms in the United States.
Pure Comparative Negligence
Pure comparative negligence generally allows a plaintiff to pursue the portion of damages attributed to another party, even when the plaintiff carries substantial fault.
For example, a person assigned 80 percent of the fault may still pursue the remaining percentage under a pure comparative negligence system.
The exact calculation depends on applicable law and proven damages.
Modified Comparative Negligence
Modified comparative negligence places a threshold on a claimant’s ability to pursue damages.
Jurisdictions commonly use either a 50 percent or 51 percent threshold.
The 50 Percent Bar Rule
Under a 50 percent bar approach, the claimant generally cannot pursue damages after reaching the jurisdiction’s specified level of responsibility.
The exact statutory or judicial wording matters when applying the rule.
The 51 Percent Bar Rule
A 51 percent approach creates a slightly different threshold.
A claimant assigned 50 percent of the fault may receive different treatment from someone assigned 51 percent.
This distinction illustrates why state-specific rules matter.
What Is Contributory Negligence?
Contributory negligence differs from comparative negligence.
Traditional contributory negligence can prevent a plaintiff from pursuing damages when their own negligence contributed to the injury.
Only a small number of U.S. jurisdictions continue to apply the traditional contributory negligence rule.
Read Cornell’s overview of contributory negligence for additional legal context.
How Do Courts Determine Fault Percentages?
No single nationwide formula assigns fault percentages.
Courts may evaluate the conduct of each party and compare that conduct with the applicable standard of care.
Evidence can include:
- Photographs
- Video recordings
- Witness testimony
- Police or incident reports
- Physical damage
- Traffic evidence
- Documents
- Expert testimony
Comparative Negligence in Car Accidents
Car crashes provide a common example of shared-fault disputes.
One driver might fail to yield while another may be traveling too fast for the conditions.
The legal analysis may consider whether each action contributed to the collision.
Our guide on what happens after a car accident discusses evidence and documentation that may become relevant after a crash.
Comparative Negligence Beyond Vehicle Collisions
Comparative negligence is not limited to car accidents.
Shared-fault questions may arise in premises liability, pedestrian accidents, bicycle incidents, product disputes, and other negligence cases.
Premises Liability Example
Consider a claim involving an allegedly dangerous condition on property.
The dispute may examine what the property owner knew, what the visitor knew, and what actions each person took.
If both parties contributed to the incident, comparative fault principles may become relevant.
Who Determines Comparative Negligence?
Different parties may evaluate fault during different stages of a dispute.
An insurance company may assign fault percentages while reviewing a claim.
If litigation proceeds, a judge or jury may make findings based on evidence and the applicable legal standards.
An insurer’s internal decision does not necessarily resolve the question for a court.
How Does Comparative Negligence Affect Damages?
Comparative negligence generally affects the portion of proven damages attributed to each party’s responsibility.
Suppose a plaintiff establishes $100,000 in damages and receives 25 percent of the fault.
Under a system permitting the claim, the applicable calculation may reduce the damages according to that percentage.
This is only an illustration. Real cases depend on jurisdiction-specific law and the damages supported by evidence.
Why Evidence Matters in Shared Fault Disputes
A small factual difference may affect how responsibility is allocated.
Video footage, photographs, witness accounts, vehicle damage, and other records may provide context that personal recollections cannot.
Statements May Also Become Relevant
Statements by the parties may become part of an insurance investigation or legal dispute.
The meaning and legal significance of a statement depend on its context and applicable evidence rules.
Can a Lawyer Review Comparative Negligence Issues?
An attorney may evaluate the evidence and explain the shared-fault rules that apply in the relevant jurisdiction.
The lawyer may also examine arguments made by another party or insurance company.
Learn more about that role in what a personal injury lawyer does.
If you plan to discuss a fault dispute with an attorney, read what to bring to a lawyer consultation.
Comparative Negligence Depends on State Law
The most important point is that comparative negligence does not operate as one nationwide rule.
States may use pure comparative negligence, modified comparative negligence, or contributory negligence.
Thresholds and legal interpretations can also change. State-specific statutes and court decisions provide the controlling rules.
Attorney Archive publishes general legal information for educational purposes. This article does not provide legal advice or create an attorney-client relationship.