Certainty of terms subject of the contract. Does not need to be in any special way, as long as they are accepting the offer aware. Reliability of the source is questionable: holding an offer open means nothing unless there is consideration. for a car okay; for not okay; different value is some present: some contracts may not require considerations: Capacity: a contract under seal is free from the analysis of consideration. Once promised the consideration in value or in material, can"t go back to change it even if under gratuitous promise or under good faith. Consideration was impaired due to own detriment at first. Valid contracts for necessities of life food, shelter, education. Other contracts are voidable at the minor"s discretion: drunks: No exception for immediate performance and necessities. Window to repudiate is quire short, once the capacity is.