Contract: a deliberate and complete agreement between two or more competent persons, not necessarily in writing, supported by mutual consideration, to do some act voluntarily. By definition, a contract is enforceable in a court of law. An agreement between two parties that is enforceable in a court of law: agreement: an agreement is composed of an offer to enter into a contract and an acceptance of that offer. The informing idea behind a contract is that there has been a. There must be at least two parties to any contract, who must have legal capacity. As a general rule, only parties to a contract can sue and be sued on it: supported by mutual consideration: a contract involves a bargain or exchange between the parties. This means that each party must give something of value in exchange for receiving something of value from the other party.