What does the parol evidence rule govern?

The parol evidence rule governs the inclusion of evidence outside a written contract that contradicts or modifies its terms. This legal principle is based on the notion that when parties have reduced their agreement to writing, any prior or contemporaneous oral or written statements that would alter the terms of that written document are generally inadmissible in court. The rule aims to uphold the finality of written agreements and reduce disputes about the parties' intentions by limiting the consideration of extrinsic evidence that could undermine the established terms of the contract.

In essence, if there is a written contract that is deemed to be complete, any evidence that attempts to assert an additional term or contradiction to what is stated in the contract will typically be excluded. The parol evidence rule thus serves to protect the integrity of written contracts and uphold the principle that parties should be held to the agreements they have formally executed.

This understanding clarifies why the focus is on evidence that contradicts the terms of a written agreement, which fundamentally aligns with the essence of the parol evidence rule.