Causation is the third element of a negligence claim and requires showing that the defendant’s conduct actually and legally caused the plaintiff’s harm.
On the bar exam, causation questions frequently test both “but for” causation and foreseeability, often involving multiple actors or unexpected events. Even if duty and breach are satisfied, there is no liability unless the defendant’s actions caused the injury.
What Is Causation in Negligence?
Causation is divided into two components: actual cause and proximate cause.
Both must be satisfied for liability to attach.
Actual Cause (“But For” Causation)
Actual cause asks whether the harm would have occurred “but for” the defendant’s conduct.
If the injury would not have happened without the defendant’s actions, actual causation is satisfied.
In cases involving multiple sufficient causes, courts may apply a “substantial factor” test.
Proximate Cause (Scope of Liability)
Proximate cause limits liability to harms that are reasonably foreseeable.
Even if the defendant actually caused the harm, they are not liable for highly unusual or unforeseeable consequences.
Intervening and Superseding Causes
An intervening cause is an event that occurs after the defendant’s conduct and contributes to the harm.
If the intervening event is foreseeable, the defendant remains liable. If it is unforeseeable and breaks the chain of causation, it becomes a superseding cause and cuts off liability.
How Causation Is Tested on the Bar Exam
Causation is often tested by combining multiple events or actors.
On essays, clearly separate actual cause and proximate cause. On multiple-choice questions, look for foreseeability and whether any intervening events break the chain of liability.