What it is
When a plaintiff sues for negligence in Pennsylvania, the jury is asked to assign percentages of fault to each party. Three numbers result: the plaintiff's percentage, each defendant's percentage, and the total damages (which must equal 100% across all responsible parties).
The plaintiff's percentage of fault has two effects under Pennsylvania law:
1. Recovery reduction — total damages are reduced by the plaintiff's percentage. A plaintiff awarded $100,000 in damages who is 30% at fault recovers $70,000. 2. 51% bar — if the plaintiff's percentage of fault is 51% or higher, the plaintiff recovers nothing. The threshold is a "modified" rather than "pure" comparative system: in a pure system, even a 99%-at-fault plaintiff recovers 1% of damages; in PA's modified system, anyone above 50% recovers nothing.
The 51% line is significant. A plaintiff who is 50% at fault recovers half her damages; a plaintiff who is 51% at fault recovers nothing. Cases close to the line are won and lost on small differences in jury perception of fault.
The rule applies to most negligence-based tort claims — motor vehicle accidents, slip and falls, medical malpractice, premises liability. It does not apply to intentional-tort claims (battery, fraud, defamation), strict-liability claims (products liability under § 402A), or breach of contract.
Where it comes from
- Statute: 42 Pa. C.S. § 7102 (Pennsylvania's comparative negligence statute, enacted 1976)
- Modified-rather-than-pure rule: § 7102(a) — "the plaintiff's recovery shall be diminished in proportion to the amount of negligence attributed to the plaintiff" but only if "the negligence was not greater than the causal negligence of the defendant or defendants"
- Joint and several liability — Fair Share Act of 2011: § 7102(a.1) — significantly modified PA's joint-and-several liability rules
- Strict liability cases: § 7102(b.1) — comparative negligence does not reduce a plaintiff's recovery in products-liability or other strict-liability cases under most circumstances
The 1976 statute replaced PA's prior contributory-negligence rule, under which any plaintiff fault — even 1% — barred recovery entirely. The shift to modified comparative negligence was intended to align PA with the majority of states.
Who it applies to
| Type of claim | Comparative negligence applies? |
|---|---|
| Auto-accident negligence | Yes |
| Premises liability (slip/fall) | Yes |
| Medical malpractice | Yes |
| Negligence-based property damage | Yes |
| Wrongful death (negligence-based) | Yes |
| Products liability (strict) | Limited — generally does not bar recovery |
| Intentional torts (battery, fraud) | No |
| Defamation | No |
| Breach of contract | No (different doctrine — mitigation of damages) |
| Workers' compensation | No (no-fault system) |
Joint and several liability — when one of multiple defendants pays more than its share — was significantly altered by the Fair Share Act of 2011 (codified at § 7102(a.1)). Under the Fair Share Act, a defendant whose responsibility is less than 60% is liable only for its proportional share, not for the entire judgment. Defendants whose responsibility is 60% or more remain jointly and severally liable.
There are several exceptions to the Fair Share Act under which traditional joint-and-several liability still applies — including for intentional torts, certain hazardous-substance claims, and where a defendant has been convicted of certain crimes related to the harm.
What it means in practice
Scenario 1 — Auto accident, plaintiff partly at fault. A driver runs a red light and is struck by another vehicle. Both drivers were partially at fault — the running driver crossed against the signal, but the other driver was speeding. The jury assigns 60% to the running driver and 40% to the speeding driver, and awards $300,000 in damages. The running driver (the plaintiff) recovers nothing because her fault exceeds 50%. The speeding driver (the plaintiff in a separate cross-claim) recovers $180,000 ($300,000 × 60% defendant fault) — reduced from his full damages by his own 40% fault.
Scenario 2 — 50/50 split. A pedestrian is struck while crossing mid-block. A jury concludes the driver was 50% at fault (speeding, not looking) and the pedestrian was 50% at fault (jaywalking, not looking either). Damages are $100,000. Because the pedestrian's fault is not greater than the driver's fault, the 51% bar does not apply — the pedestrian recovers $50,000 (50% of damages).
Scenario 3 — Slightly past the 51% line. Same case but the jury splits 51% pedestrian / 49% driver. The pedestrian's fault is greater than the driver's, so the pedestrian recovers nothing. A single percentage point — sometimes a single juror's perception — can be the difference between a $50,000 recovery and zero.
Scenario 4 — Multiple defendants under Fair Share. A construction worker is injured when scaffolding collapses. The jury assigns 70% fault to the general contractor, 25% to the scaffolding subcontractor, and 5% to the worker himself. The worker recovers 95% of his damages. Of that recovery, the general contractor (70% fault) is jointly and severally liable for the full amount because its fault is 60% or higher. The subcontractor (25% fault) is liable only for its 25% share under the Fair Share Act. If the worker collects from the general contractor, the general contractor can pursue contribution from the subcontractor for the 25%.