Legality Choose... Past Choose... consideration Interim Choose... agreement Offer Choose... Invitation to Choose... treat Choose... 2 Finish attempt a binding contract that will subsequently be put into a more formal document; usually referred to as an agreement of purchase and sale in a real estate transaction a tentative promise to do something if another party consents to do what the first party requests an invitation to engage in the bargaining process. an element of a valid contract; the object and consideration of the contract must be legal and not against public policy something completed before an agreement is made, it is not valid consideration