• This rule usu. operates to prevent a party from introducing extrinsic evidence of negotiations that occurred before or while the agreement was being reduced to its final written form. See INTEGRATION(2); MERGER(2). Cf. FOUR-CORNERS RULE. [Cases: Evidence 397. C.J.S. Evidence §§ 1159, 1165, 1189.]
parol evidence rule
Contracts. The common-law principle that a writing intended by the parties to be a final embodiment of their agreement cannot be modified by evidence of earlier or contemporaneous agreements that might add to, vary, or contradict the writing.