The “eggshell skull” or “eggshell plaintiff” rule states that someone who harms another must pay for whatever damage the injured person suffered, even if it was much worse than anyone would have expected.
The “eggshell skull” rule is named after the example frequently used in law schools. The example describes an imaginary person who has an extremely thin skull that is as fragile as an eggshell, even though he looks completely normal. This person is hit in the head by someone else. A normal person would only have been bruised by the hit, but the person with the eggshell skull dies. The “eggshell skull” rule says that the person who hit the eggshell-skulled person is responsible for the much greater harm caused by the death, not just the amount of harm that a normal person would have suffered.
The eggshell skull rule also applies in cases of negligence or carelessness. For instance, suppose the plaintiff in a personal injury case is a bicycle repairman who negligently “fixes” a child’s bicycle. Unknown to the repairman, the child has hemophilia. While the child is riding the bicycle, it breaks because the repairman did not fix it correctly. The child falls and scrapes her knees on the pavement and has to be hospitalized due to severe blood loss caused by her hemophilia. In this case, the plaintiff is responsible for all of the child’s hospital bills, even though he did not foresee that the child might bleed dangerously if she fell off the broken bicycle.
The eggshell skull rule is based on the idea that it is fair for a defendant to compensate an injured person for the harm he actually caused. Therefore, the defendant must take the plaintiff “as he finds him,” invisible medical conditions and all. The defendant is not, however, required to show a higher duty of care to the eggshell plaintiff. The duty of care is the same whether or not a plaintiff has a pre-existing physical, mental or emotional condition.
One exception to the eggshell skull rule is the plaintiff who harms himself. For instance, suppose a plaintiff gets very drunk one night and wanders into the road, where she is hit by a speeding driver. Because of the high amount of alcohol in her system has thinned her blood, the plaintiff bleeds much more quickly and suffers severe brain damage as a result of the accident.
Although the driver was negligent by speeding, the plaintiff made herself more susceptible to damage by drinking. In this case, the defendant may not be liable for the entire extent of the plaintiff’s damages because the plaintiff had a hand in them. This exception is similar to the rules of contributory negligence and comparative negligence used in some courts.
When a personal injury case is tried in court, the attorneys and the judge usually determine whether the “eggshell skull” rule applies. If it does, the judge will instruct the jury to consider it when the jury calculates how much the plaintiff should receive in damages. Specifically, the judge will tell the jury to calculate the total amount of the plaintiff’s damages, regardless of whether they were much higher than a normal person’s damages would have been. For instance, in the case of the child with hemophilia who fell off her bicycle, the judge would instruct the jury to consider all of the child’s hospital bills for her condition, even though a normal child’s medical bills would be considerably lower.