Restatement Second of Contracts § 87
- An offer is binding as an option contract if it
- is in writing and signed by the offeror, recites a purported consideration for the making of the offer, and proposes an exchange on fair terms within a reasonable time; or
- is made irrevocable by statute.
- An offer which the offeror should reasonably expect to induce action or forbearance of a substantial character on the part of the offeree before acceptance and which does induce such action or forbearance is binding as an option contract to the extent necessary to avoid injustice.
Copyright, The American Law Institute