The following abstract explains Nevada’s parol evidence rule and its application to claims made in her courts.
Parol evidence is inadmissible “[w]hen parties reduce a contract to writing, all prior oral negotiations and agreements are merged in the writing, and the instrument must be treated as containing the whole contract, and parol [evidence] is not admissible to alter its terms.” Cage v. Phillips, 21 Nev. 150, 26 P. 60 (1891). The parol evidence rule is based on the principle that a written contract is more reliable than oral testimony when determining the terms of an agreement. Michael B. Metzger, The Parol Evidence Rule: Promissory Estoppel’s Next Conquest?, 36 Vand. L. R. 1383, 1386-87 (1983) (hereinafter “Metzger”).