Collateral Order Doctrine

Orders conclusively resolving important questions separate from the merits and effectively unreviewable later may be appealed.

Related Appealability & Review rules

• Final Judgment RuleAppeals generally lie only from final judgments resolving all claims and parties.
• Interlocutory AppealsCertain orders may be appealed immediately, such as injunctions and certified controlling questions of law.
• Appeals: Standards of ReviewLaw is reviewed de novo; facts for clear error; discretionary decisions for abuse of discretion.

Part of Civil Procedure on Core Legal Rules — foundational MBE-tested principles with primary-source citations.