"Assumption of risk" is a defense that is frequently raised in personal injury (tort) cases. The defendant asserts that the plaintiff was fully aware that the particular activity which led to the injury was hazardous, and thus was responsible for his/her own resultant injury.
More specifically, this is known as primary assumption of risk. This occurs when a plaintiff has, either expressly or by implication, relieved the defendant of any responsibility to mitigate the risk associated with the activity that caused the injury in question. The theory is that by assuming the risk, the plaintiff also assumed all liability. However, in order for this principle to apply, it must be proven that the plaintiff had clear knowledge of any risk involved.
Primary assumption of risk is a defense that is most often used in injury cases that involve high-risk recreational activities such as sky diving, bungee-jumping or paragliding. In these cases, primary assumption of risk is fairly easy to prove Unless gross negligence on the part of the defendant (i.e., the plaintiff failed to provide proper equipment and instruction) can be clearly demonstrated, the courts will dismiss these cases.
Before the enactment of workers' compensation laws, assumption of risk was a common defense in employee injury cases. This defense argued that by agreeing to do a job, the employee implicitly assumes responsibility for all ordinary risks associated with a particular task. Not only have workers' compensation laws abolished this defense altogether, it is now known that corporations have regularly withheld information from employees over the past several decades regarding the risks associated with many toxic substances used in industrial processes - including asbestos. It is therefore highly unlikely that the plaintiff in an asbestos case will raise this particular defense.