The first two determinations you must make are whether a party in this case made an offer, and if an offer was made, whether the other party accepted the offer. Must be for legal purposes; Consideration; Offer and Acceptance (required); Executed vs.Executory; Equitable Title (Equitable Conversion) vs. To create a valid contract under Massachusetts law, there must be: • An offer. There is usually a window of time from when the Offer to Purchase is accepted to when a Purchase and Sale agreement is signed. Generally, the elements of a legally enforceable contract are assent, a valid offer, acceptance, and consideration.