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 双语律师Jenna,国际知名法学院环境法专业,擅长翻译各类与环境、社会及管治 (ESG)相关的法律文件。