Does our merger clause stop the other side proving a side deal or a pre-signing promise?
The parol evidence rule in Ohio is, in the words of a 1952 syllabus the Supreme Court of Ohio still quotes, "a rule of substantive law which, when applicable, defines the limits of a contract". Its content, as the Court states it from Williston on Contracts, is that absent fraud, mistake or other invalidating cause, the parties' final written integration of their agreement may not be varied, contradicted or supplemented by evidence of prior or contemporaneous oral agreements, or prior written agreements (Galmish). An integration clause does not add to that: the Supreme Court of Ohio held that the presence of an integration clause makes the final written agreement no more integrated than does the act of embodying the complete terms into the writing, and that the presence of an integration provision does not vitiate the principle that parol evidence is admissible to prove fraud.
The trap
The fraud exception is narrower than it looks, and the limit is the one that decides most Ohio cases: the rule may not be avoided 'by a fraudulent inducement claim which alleges that the inducement to sign the writing was a promise, the terms of which are directly contradicted by the signed writing', and 'an oral agreement cannot be enforced in preference to a signed writing which pertains to exactly the same subject matter, yet has different terms' (Galmish, quoting Marion Production Credit Assn. v. Cochran, paragraph three of the syllabus). So the counterparty whose complaint is that it was promised a different number from the one the writing states loses; the counterparty whose complaint is about something the writing does not address at all is outside the rule. Drafting a stronger merger clause does not change either outcome, because Galmish holds the clause adds nothing to integration and does not touch the fraud exception.
4 authorities
The words that state the rule
The parol evidence rule applies, in the first instance, only to integrated writings, and an express stipulation to that effect adds nothing to the legal effect of the instrument. The presence of an integration clause makes the final written agreement no more integrated than does the act of embodying the complete terms into the writing. Thus, the presence of an integration provision does not vitiate the principle that parol evidence is admissible to prove fraud.
The words that state the rule
However, the parol evidence rule may not be avoided “by a fraudulent inducement claim which alleges that the inducement to sign the writing was a promise, the terms of which are directly contradicted by the signed writing. Accordingly, an oral agreement cannot be enforced in preference to a signed writing which pertains to exactly the same subject matter, yet has different terms.” Marion Prod. Credit Assn. v. Cochran (1988), 40 Ohio St.3d 265 , 533 N.E.2d 325 , paragraph three of the syllabus.
The words that state the rule
“The parol evidence rule is a rule of substantive law which, when applicable, defines the limits of a contract.” Id., paragraph one of the syllabus.
The words that state the rule
The parol evidence rule states that “absent fraud, mistake or other invalidating cause, the parties’ final written integration of their agreement may not be varied, contradicted or supplemented by evidence of prior or contemporaneous oral agreements, or prior written agreements.” 11 Williston on Contracts (4 Ed.1999) 569-570, Section 33:4.
“Defective” means that reading found something to correct. What you are reading is the rule as it stands after that reading.