Contract law in the legal context of the United States generally allows for a contract which is called into being by the exchange of verbal expressions to be as valid as one which is set forth in writing. This general provision for a verbal contract may, however, be modified in certain jurisdictions by specific contract law requirements for a contract to be set down in specific circumstances and toward specific ends. Moreover, contract law for an area may or may not provide for the difficulties which can arise in carrying out a verbal contract.
The lack of a written contract can present problems in terms of the lack of proof as to what was agreed to under contract law. As such, judges administering contract law may be forced to apply a standard of fairness in order to resolve the contract dispute. In this way, a verbal contract, while valid, may not be effective.