Impracticability Defense

Impracticability excuses performance when extreme difficulty or expense fundamentally alters the nature of the performance.

Related Excuse & Discharge rules

• Impossibility DefenseObjective impossibility excuses performance when it becomes literally impossible due to unforeseen events.
• Frustration of PurposeFrustration excuses performance when the contract’s principal purpose is substantially undermined by unforeseen events.
• Accord and SatisfactionA new agreement to discharge a claimed obligation is an accord; performance of the accord is satisfaction.
• NovationA novation is a substituted contract replacing one party with another, requiring consent of all parties.
• Accord vs. ModificationAn accord is a new agreement for substitute performance; a modification changes existing obligations.

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