Comparative fault (also called comparative negligence) is the legal doctrine that reduces your personal injury damages by the percentage of fault attributed to you. If a jury finds you 25% responsible for the accident and your total damages are $200,000, you recover $150,000. The rule exists in some form in every US state (except five that still apply the harsher contributory-negligence bar), in England and Wales, Canada, Australia, Ireland, and across all European jurisdictions covered on this site.
Four systems exist: pure comparative (recover at any fault level), modified-50% (barred at 50%+ fault), modified-51% (barred at 51%+ fault), and contributory negligence (barred at any fault, even 1%). Most states and all non-US jurisdictions use either pure comparative or a close equivalent.
The four comparative fault systems
| System | Recovery rule | Used in |
|---|---|---|
| Pure comparative | Recover at any fault level; damages reduced by your % | 13 US states + NY, CA, FL; UK, Ireland, Canada, Australia, EU |
| Modified — 50% bar | Recover only if your fault is less than 50% | 12 US states |
| Modified — 51% bar | Recover only if your fault is 50% or less | 21 US states |
| Contributory negligence | Any fault (even 1%) bars recovery entirely | AL, MD, NC, VA, DC |
Pure comparative fault
Under pure comparative fault, you can recover damages even if you are 99% at fault — your recovery is simply reduced by your percentage of responsibility. If damages total $500,000 and you are 80% at fault, you receive $100,000.
This is the most claimant-friendly system. It is used in 13 US states (including California, New York, and Florida), and is the default approach in England and Wales (under the Law Reform (Contributory Negligence) Act 1945), Ireland, Canada, Australia, and all European jurisdictions on this site.
Modified comparative fault — 50% bar
Under the modified-50% system, you can recover only if your fault is less than 50%. If you are exactly 50% or more at fault, you are barred from recovery entirely. Twelve US states use this system.
Modified comparative fault — 51% bar
Under the modified-51% system, you can recover if your fault is 50% or less — you are barred only if your fault exceeds 50%. This is the most common US system, used in 21 states. The practical difference from the 50% bar is narrow but significant: a 50/50 split allows recovery under the 51% bar but not under the 50% bar.
Contributory negligence (total bar)
Contributory negligence is the harshest system: any fault by the claimant — even 1% — bars recovery entirely. Only five US jurisdictions still apply it: Alabama, Maryland, North Carolina, Virginia, and the District of Columbia.
US state-by-state breakdown
| System | States |
|---|---|
| Pure comparative | Alaska, Arizona, California, Florida, Kentucky, Louisiana, Mississippi, Missouri, New Mexico, New York, Rhode Island, South Dakota, Washington |
| Modified — 50% bar | Arkansas, Colorado, Georgia, Idaho, Kansas, Maine, Nebraska, North Dakota, Oklahoma, Tennessee, Utah, West Virginia |
| Modified — 51% bar | Connecticut, Delaware, Hawaii, Illinois, Indiana, Iowa, Massachusetts, Michigan, Minnesota, Montana, Nevada, New Hampshire, New Jersey, Ohio, Oregon, Pennsylvania, South Carolina, Texas, Vermont, Wisconsin, Wyoming |
| Contributory negligence | Alabama, Maryland, North Carolina, Virginia, District of Columbia |
International approaches
| Jurisdiction | System | Key statute |
|---|---|---|
| England & Wales | Pure comparative (contributory negligence reduces damages) | Law Reform (Contributory Negligence) Act 1945 |
| Ireland | Pure comparative | Civil Liability Act 1961, s.34 |
| Canada | Pure comparative (all provinces) | Varies by province; Ontario Negligence Act |
| Australia | Pure comparative (all states) | State Civil Liability Acts |
| Germany | Pure comparative | BGB §254 (Mitverschulden) |
| France | Partial; Badinter Act (1985) limits driver fault arguments | Loi Badinter, Art. 3-4 |
| Spain | Pure comparative | Código Civil, Art. 1902; Law 35/2015 |
Impact on settlement negotiations
In practice, comparative fault is the single most powerful lever an insurance adjuster has to reduce a settlement. Even in pure-comparative-fault states, the adjuster will argue for a higher claimant-fault percentage to drive down the offer.
The negotiation often centres on the fault split rather than the total damages figure. A claimant whose damages are valued at $100,000 might receive an offer of $60,000 because the adjuster attributes 40% fault — even if the claimant believes their fault is 10%.
Frequently asked questions
What is comparative fault in personal injury?
What is the difference between pure and modified comparative fault?
Which states use contributory negligence?
How does comparative fault work in the UK?
Does comparative fault affect pain and suffering?
Who decides the percentage of fault?
Sources
- Restatement (Third) of Torts: Apportionment of Liability (American Law Institute)
- Law Reform (Contributory Negligence) Act 1945 (England & Wales)
- Civil Liability Act 1961 (Ireland), s.34
- BGB §254 — Mitverschulden (Germany)
- Loi Badinter (1985) — French motor accident liability
- National Conference of State Legislatures — comparative fault survey