Four systems, and Pennsylvania uses the more common threshold
American fault law splits into four real categories: pure comparative negligence, modified comparative negligence with a 50% bar, modified comparative negligence with a 51% bar, and pure contributory negligence. Pennsylvania uses the 51% bar under 42 Pa.C.S. § 7102 — the more typical of the two modified thresholds nationally.
The 50/51 distinction, precisely
A claimant found exactly 50% at fault still recovers half of their damages under Pennsylvania's rule, because the bar applies only when the claimant is more negligent than the defendant. A claimant found 51% at fault recovers nothing at all.
A genuinely significant 2011 reform
Pennsylvania's Fair Share Act, effective June 28, 2011, changed how liability is split among multiple defendants. Before the Act, Pennsylvania generally followed a joint-and-several model, where any one defendant could potentially be held liable for the full judgment regardless of their individual percentage of fault. The Fair Share Act moved toward a several-only model: each defendant is now generally liable only for the percentage of negligence the jury actually attributed to them.
The stricter alternative: a 50% bar
A smaller group of about 12 states, including Georgia and Kansas, use a stricter version: recovery is barred the moment the claimant's fault is equal to the defendant's, not only when it exceeds it.
Pure comparative negligence and contributory negligence: the two extremes
At the more forgiving end of the spectrum, pure comparative negligence states like California never bar recovery for ordinary fault at all. At the far stricter end, the five contributory negligence jurisdictions — Alabama, Maryland, North Carolina, Virginia, and DC — bar recovery entirely for any fault, even 1%. See our guide to the other states using a 51% bar for Pennsylvania's closest peer group nationally.