The law of contracts has often treated options quite differently from other contractual transactions; for example, the characterization of a transaction as an option contract calls forth specially required formalities, but on the other hand often has the effect of releasing parties from doctrinal limitations on their contractual freedom, such as the duty to mitigate damages or the rule that holds excessively high liquidated damages void as penalties. Such differential treatment is challenging to explain from a functional viewpoint, in part because all contracts resemble options to the extent they are enforceable in terms of monetary damages, and in part because contracts that are nominally structured as explicit options can be close economi...