What does "but-for" test determine in tort law?

The "but-for" test is a fundamental concept in tort law used to establish causation between a defendant's actions and a plaintiff's injury. This test helps determine whether the injury would have occurred "but for" the defendant's conduct. In other words, if the defendant had not acted in the way they did, would the plaintiff still have suffered the same injury? If the answer is no, then the defendant's actions are considered a factual cause of the injury.

This test is essential for establishing a direct link between the defendant's behavior and the plaintiff’s harm, which is a crucial element for proving liability in tort cases. By focusing on causation, the "but-for" test provides clarity in assessing whether the defendant should be held responsible for the resulting consequences of their actions.