From LawGuru Wiki
Contributory negligence is a common law defence to a claim or action in tort. It applies to a situation where a plaintiff or claimant has, through their own negligence, caused or contributed to the injury they suffered from a tort. An example might be a situation in which a pedestrian crosses a road carelessly and is hit by a driver who is also driving carelessly.
 Scope of the Defence
At common law, contributory negligence was an absolute defence. If a defendant successfully raised the defence, he would be able to avoid liability for the tort completely. This could lead to injustice where the negligence of a plaintiff or claimant was slight. The defence of contributory negligence would prevent them from recovering any damages at all.
Most jurisdictions in the United States have abolished the doctrine altogether (only Virginia, Maryland, Alabama, North Carolina, and D.C. are still contributory negligence districts), instead adopting a comparative negligence standard that simply reduces the damages to be awarded by an amount reflecting the degree to which the plaintiff's negligence contributed to the injury.
Some jurisdictions have altered the common law so that contributory negligence is only a partial defence, meaning that a defendant avoids only part of their liability. For example, in England and Wales, the Law Reform (Contributory Negligence) Act 1945 had this effect. In practice this has a similar effect to the doctrine of comparative negligence (see Acts of the claimant).
 Proof of the defence
In some jurisdictions the defendant has to prove the negligence of the plaintiff or claimant; in others the burden is on the plaintiff or claimant to disprove their own negligence. The tortfeasor may still be held liable if he had the last clear chance to prevent the injury.
Contributory negligence was the title and subject of a circa 1982 poem by Attila the Stockbroker, a UK performance poet, protesting at a mere fine given to a rapist, after the high court judge determined that the women concerned in some way provoked or contributed to the rape.