substantial factor testglossary / SUBSTANTIAL-FACTOR TEST substantial-factor test. Torts. The principle that causation exists when the defendant’s conduct is an important or significant contributor to the plaintiff’s injuries. Cf. BUT-FOR TEST. [Cases: Negligence 380.] 词条贡献者 资深译员Walker,毕业于亚洲一流的高级翻译学院,擅长翻译各类与尽职调查相关的法律文件。