Contract rules can be justified by utilitarian theories (such as efficiency theory), which are concerned with promoting rules that enhance societal wealth and utility. Contract rules can also be justified by rights-based theories (such as promissory and reliance theories), which are concerned with protecting the contractual freedom and interests of the individual parties to the contract. Or, contract rules can be analyzed through the lenses of a host of other theories, including critical legal theory, bargain theory, and so on. Because no single, unitary theory can ever explain the complex body of laws and societal conventions surrounding contracts, the best rule to govern any particular situation is the one that can be justified by multipl...