USA

21 Intention to Be Legally Bound

Neither real nor apparent intention that a promise be legally binding is essential to the formation of a contract, but a manifestation of intention that a promise shall not affect legal relations may prevent the formation of a contract.

27 Existence of Contract Where Written Memorial Is Contemplated

Manifestations of assent that are in themselves sufficient to conclude a contract will not be prevented from so operating by the fact that the parties also manifest an intention to prepare and adopt a written memorial thereof; but the circumstances may show that the agreements are preliminary negotiations.