Imagine this set of facts: Driver A makes an illegal left turn without a signal. Meanwhile, Driver B is speeding in the opposite direction and collides with Driver A's car while it is making the illegal turn. Both drivers suffer serious injuries. Who wins the lawsuit? Does anybody win it?
Prior to a decision of the California Supreme Court in 1975, neither driver in our hypothetical auto accident could recover from the other because each was negligent to some degree. Under the prior rule in California (and most other states at the time), a party who was partially at fault for an accident was deemed to be "contributorily negligent" and was denied any recovery. Under this rule, neither Driver A nor Driver B could win the lawsuit. In its most extreme application, this rule denied all damages to plaintiffs who were only minimally at fault.
In Li v. Yellow Cab Co., the California Supreme Court rejected this "all or nothing" approach to contributory negligence. Instead, the court ruled that the fault of each party must be measured or compared and that a party's damages must be reduced by the percentage of fault for which he or she was responsible. In our example, the jury would be instructed to allocate fault between the two drivers. If the jury determined that Driver B was 60% at fault because he was speeding, he would be entitled to recover 40% of his damages and Driver A would be able to recover 60% of his damages. The allocation of fault is made without reference to the monetary amount of damages found by the jury. If Driver A was entitled to recover $100,000, his damages, after being reduced by his percentage of fault (40%), would be $60,000. If Driver B's damages were $20,000, he would be entitled to recover $8,000 (40% of $20,000). Driver A would, in the end, recover $52,000 from Driver B.
As this example makes clear, the allocation of fault in a personal injury case can become quite complicated. Any person involved in an auto accident involving personal injury should consult an attorney with extensive experience in such lawsuits to evaluate his or her claim and to determine the best strategy for seeking a recovery.
Source: California Civil Jury Instructions (CACI) 405, "Comparative Fault of Plaintiff," accessed Feb. 22, 2015