Causation Definition

In litigation, the element of a case that proves some injury, harm, or loss was caused by an act or omission.

For example, in a breach of contract case, the plaintiff (the party who's suing) must show that the defendant's (the party being sued) breach of contract caused the plaintiff to suffer an injury or loss. In an auto accident case, the plaintiff must tie the defendant's negligent driving to the plaintiff's injuries, proving that the former caused the latter.

Most often, proof of causation requires proving two things:

• actual or but-for causation, meaning that the injury or loss wouldn't have occurred but for the defendant's act or omission, and
• proximate causation, meaning that the injury or loss was a reasonably foreseeable consequence of the defendant's act or omission.

(See also: actual cause, proximate cause)