Legal Definitions - Heydon's case, rule in

Heydon's case, rule in, also known as the mischief rule, is a doctrine used in statutory construction. It states that a statute should be interpreted by first identifying the problem or "mischief" that the statute was designed to remedy. Then, a construction should be adopted that will suppress the problem and advance the remedy.

For example, let's say there is a statute that prohibits the sale of alcohol to minors. If a court is interpreting this statute using the mischief rule, they would first identify the problem or mischief that the statute was designed to remedy, which is the harm caused by minors consuming alcohol. The court would then adopt a construction that would suppress this problem and advance the remedy, such as interpreting the statute to include not only the sale of alcohol but also the provision of alcohol to minors.

The mischief rule is one of several approaches used in statutory construction, including the golden rule, plain-meaning rule, and equity-of-the-statute rule.