Chapter 17

The Parol Evidence Rule

Module V: Interpretation & Terms

This chapter explains when a final written agreement excludes earlier negotiations and when supplemental terms may still be admitted. The tensions in The Breaking mirror the doctrine’s central question: what prior understandings survive once the parties reduce their deal to writing?

Doctrinal map

The parol-evidence rule (R2d §§ 209–218; UCC § 2-202) governs what extrinsic evidence may be admitted to vary, contradict, or supplement a writing. The chapter teaches the integration analysis: total integration (parol barred entirely as to all terms) vs. partial integration (parol may supplement but not contradict). Gianni v. Russell applies the ‘naturally would have been included’ test. UAW-GM v. KSL Recreation gives effect to the merger clause as strong (often conclusive) evidence of total integration.

Key Sources

Key Rules

Cases

Exercise: The Breaking →