The L.A. Times nicely sums the case up so:
The ruling came in a lawsuit by Smriti Nalwa, who fractured her wrist in 2005 while riding in a bumper car with her 9-year-old son and being involved in a head-on collision. Rosenberg said Great America had told ride operators not to allow head-on collisions, but failed to ask patrons to avoid them.The legal doctrine at issue is the common law (i.e. judge made) principle of assumption of risk, whereby someone who undertakes an activity knowing of the risks involved cannot later sue the person who organized or oversaw the activity. Up to this point, California courts had apparently limited the use of the doctrine to risky sports, but in this case they drew an analogy between risky sports and risky amusement park rides and found them to be sufficiently similar to allow for an extension of the doctrine.
The court said Nalwa's injury was caused by a collision with another bumper car, a normal part of the ride. To reduce all risk of injury, the ride would have to be scrapped or completely reconfigured, the court said.
"A small degree of risk inevitably accompanies the thrill of speeding through curves and loops, defying gravity or, in bumper cars, engaging in the mock violence of low-speed collisions," Justice Kathryn Mickle Werdegar wrote for the majority. "Those who voluntarily join in these activities also voluntarily take on their minor inherent risks."
Monday's decision extended a legal doctrine that has limited liability for risky sports, such as football, to now include recreational activities.
