A more thorough explanation:

Brandeis Rules, also known as Ashwander Rules, are a set of principles that guide the U.S. Supreme Court in deciding constitutional questions only when necessary and avoiding them if the case can be resolved on another issue.

The rules were outlined in Justice Brandeis's concurring opinion in Ashwander v. Tennessee Valley Authority, a 1936 case. The principles include:

• Not deciding a constitutional question in a friendly suit
• Not anticipating a question of constitutional law
• Not creating a rule of constitutional law that is broader than necessary
• Not deciding a constitutional issue if the case can be resolved on another ground
• Not ruling on the constitutionality of a statute unless the plaintiff is harmed by the statute or has accepted its benefits
• Not ruling on the constitutionality of an act of Congress without first analyzing whether it can be construed in a way that avoids the constitutional question

For example, if a person challenges a law that they have not been affected by, the court may not rule on the constitutionality of the law because the person has not been harmed by it. Similarly, if a case can be resolved on a non-constitutional issue, the court may avoid ruling on the constitutional question.