Final answer:
To support a legally binding contract, it must have consideration, which can be an exchange of something of value. Past consideration and moral consideration generally do not support a legally binding contract.
Step-by-step explanation:
In order for a contract to be legally binding, it must have consideration. Consideration is something of value that is exchanged between the parties involved in the contract. Past consideration, which is consideration given before the contract is made, will not ordinarily support a legally binding contract. Moral consideration, which is based on moral obligations rather than a bargain or exchange, also will not ordinarily support a legally binding contract. Nominal consideration, which is a very small amount of money or a token gesture, may or may not be sufficient to support a legally binding contract, depending on the circumstances.