Legal Definitions - substantial-factor test

The substantial-factor test is a principle used in tort law to determine causation. It states that the defendant's conduct is considered a significant contributor to the plaintiff's injuries. This means that if the defendant's actions played a substantial role in causing harm to the plaintiff, then they can be held liable for the damages.

For example, if a driver is texting while driving and hits a pedestrian, causing them to suffer serious injuries, the driver's conduct would be considered a substantial factor in causing the harm. Even if there were other factors that contributed to the accident, such as poor lighting or the pedestrian not paying attention, the driver's actions would still be considered a significant cause of the injuries.

Another example could be a case where a company releases a defective product that causes harm to a consumer. If it can be shown that the defect was a substantial factor in causing the harm, then the company can be held liable for the damages.

The substantial-factor test is used to determine causation in many different types of tort cases, including personal injury, product liability, and medical malpractice. It helps to ensure that those who are responsible for causing harm are held accountable for their actions.