Novus Actus Interveniens
Literal meaning: “A new intervening act”
What does the Latin term "Novus Actus Interveniens" mean in law?
Novus actus interveniens refers to an independent, intervening act that breaks the chain of causation between a defendant's original negligent conduct and the plaintiff's ultimate injury. When such an act occurs, the original defendant may no longer be held liable because the intervening event, rather than the defendant's conduct, is deemed the proximate cause of the harm. To break the causal chain, the intervening act must typically be unforeseeable, independent, and sufficient in itself to cause the injury. Foreseeable intervening acts, such as medical malpractice in treating the plaintiff's original injuries, generally do not break the chain of causation.
Source: Torts · Legal Latin
Legal Definition
Novus actus interveniens refers to an independent, intervening act that breaks the chain of causation between a defendant's original negligent conduct and the plaintiff's ultimate injury. When such an act occurs, the original defendant may no longer be held liable because the intervening event, rather than the defendant's conduct, is deemed the proximate cause of the harm. To break the causal chain, the intervening act must typically be unforeseeable, independent, and sufficient in itself to cause the injury. Foreseeable intervening acts, such as medical malpractice in treating the plaintiff's original injuries, generally do not break the chain of causation.
How It's Used
Defense attorneys raise novus actus interveniens to argue that a subsequent event, not their client's negligence, was the true cause of the plaintiff's harm. Courts must determine whether the intervening act was sufficiently independent and unforeseeable to sever the causal link, a factual inquiry that is often central to negligence litigation.
Example Sentences
The defendant argued that the victim's decision to refuse medical treatment constituted a novus actus interveniens, breaking the causal chain between the assault and the victim's death.
The court held that the arsonist's act was a novus actus interveniens that superseded the landlord's negligent failure to install smoke detectors.
Because a second driver's reckless speeding was a foreseeable intervening cause, the court refused to treat it as a novus actus interveniens absolving the first driver of liability.