The decree ( or act) of a court shall prejudice no man.

Explanation

When a court's own act — such as delay, clerical error, or procedural oversight — causes harm to a party, the court must ensure that party is not prejudiced by the court's mistake.

Where this applies

• A court loses a party's filing and then enters a default judgment against that party — the court must vacate the judgment because its own mistake cannot harm the litigant.
• A judge accidentally schedules two trials at the same time and one party cannot attend — the court cannot hold that party in default for the court's own scheduling error.
• A clerk's office miscalculates a filing deadline, and the court extends the deadline because the court's own act must not prejudice the affected party.