Masterson v. Sine
Supreme Court of California
436 P.2d 561 (1968)
Dallas and Rebecca Masterson (plaintiffs) conveyed their ranch to Medora and Lu Sine (defendants) by a grant deed reserving Dallas's option to repurchase within ten years for the original consideration minus any depreciation, with Medora being Dallas's sister; after Dallas later declared bankruptcy, his trustee and Rebecca sought to enforce the repurchase option. The trial court admitted extrinsic evidence establishing the $50,000 consideration figure and the tax-based meaning of "depreciation," but excluded the Sines' evidence that the parties had orally agreed the option was personal to the Mastersons, meant to keep the ranch within the family, and thus non-assignable to a bankruptcy trustee. Both sides appealed.
Whether evidence of a separate oral agreement is admissible to prove the terms of a written contract when it is unclear whether the written contract is intended by the parties to be complete.