Four systems, and Idaho uses the stricter middle version
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. Idaho uses the 50% bar — the less common, stricter of the two modified thresholds nationally.
Idaho's rule: barred at the threshold
Under Idaho Code § 6-801, a claimant recovers only if their negligence was not as great as the negligence of the person against whom recovery is sought — in practice, fault must be strictly below 50%.
What genuinely sets Idaho apart within this category
Idaho's 50% threshold alone isn't unique — Georgia and Colorado share it. What's genuinely distinctive is how Idaho applies that threshold when more than one defendant is involved: the "individual rule" compares the claimant's fault to each defendant separately, rather than to the defendants' combined total. This can produce outcomes no other 50%-bar or 51%-bar state would reach on identical facts, since most of those states compare the claimant against the aggregate fault of every defendant together.
The more forgiving alternative: a 51% bar
A larger group of about 21 states, including Connecticut and Hawaii, use a more forgiving version: recovery is barred only when the claimant's fault actually exceeds the defendant's, not merely equals it, and typically compares against the defendants' combined fault rather than each one individually.
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 50% bar for Idaho's closest peer group nationally.