MBE Rules · Contracts
Parol evidence — admissibility exceptions
The rule
Even with a fully integrated writing, extrinsic evidence is admissible to: (1) clarify ambiguity, (2) prove formation defects (fraud, duress, mistake, lack of consideration), (3) prove a condition precedent to formation, (4) prove a subsequent modification, or (5) interpret terms (with restrictions on plain meaning).
In plain English
Even if a contract seems complete, outside evidence can be used to explain unclear terms, show issues with how the contract was made, prove later changes, or clarify what the terms mean.
Worked example
The defendant claims a contract term is unclear. They introduce emails showing both parties agreed the term meant delivery in 30 days. The court allows this evidence to clarify the term's meaning.
Memory hook
Parol Evidence: Peek Past the Page! Clarify, correct, condition, change, or clarify terms with exceptions.
The trap
Students think: Any extrinsic evidence is barred if writing is fully integrated. Wrong, because exceptions allow it for ambiguity, defects, conditions, modifications, or interpretation.
How examiners test it
The MBE loves: contract has ambiguous term or alleged oral agreement. Trap: students forget exceptions like ambiguity or condition precedent can allow parol evidence.
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