Chapter 16

Extrinsic Evidence

Module V: Interpretation & Terms

This chapter turns to evidence outside the text, especially the parties’ conduct and the commercial practices that give language shared meaning. The reflective perspective of Galadriel’s Mirror nicely captures how outside context can clarify what a contract was understood to say.

Doctrinal map

When intrinsic evidence cannot resolve ambiguity, the chapter examines what comes from outside the document. Course of performance, course of dealing, and usage of trade carry interpretive weight under UCC § 1-303. Nanakuli Paving v. Shell Oil — the asphalt-paving ‘price protection’ usage — is the classic illustration. Wood v. Lucy, Lady Duff-Gordon shows Cardozo’s willingness to imply terms (best-efforts) from the structure of the deal to save the contract from being illusory.

Key Sources

Key Rules

Cases

Exercise: Galadriel's Mirror →