Contracts are generally bilateral. This means that both parties assume some kind of obligation and obligation. In the United States, an unusual type of unworkable contract is a personal employment contract to work as a spy or secret agent. Indeed, the secret of the contract is a condition of the contract (to maintain plausible denial). If the spy then sues the government for issues such as salary or benefits, the spy violated the contract by revealing its existence. It is therefore unenforceable for this reason, as is the public policy of maintaining national security (because an angry officer might try to reveal all the secrets of the government during his complaint).  Other types of non-opposable employment contracts include contracts that agree to work for less than the minimum wage and lose the right to workers` compensation in cases where compensation is due. Despite the required elements of the contract, there is no general obligation to enter into contracts in writing, unless an exception is expressly provided for by law. As a result, oral contracts can be binding in many circumstances. A concept of English common law, which is necessary for simple contracts, but not for special contracts (contracts per die). The court of Currie v Misa  declared the idea of « right, interest, profits, benefits or leniency, damage, loss, liability ». That is why reflection is a promise of something precious given by a pare-all in exchange for something precious that is made by a promise; and in general, the thing of value is goods, money or stock.
Evidence of action, such as an adult who promises to give up smoking, is only enforceable if a legal right is waived.    The intention to create legal relationships is essential to establishing the existence of a contract, as it distinguishes contracts created to be legally binding with contracts that are essentially social agreements or family decisions. Standard form contracts include « Boilerplate, » a series of « One Size fits all » contractual clauses. However, the term may also be closely related to the terms of the termination of the contract which set out the provisions relating to the provisions, jurisdiction, surrender and delegation, jury waiver, termination and evasion clauses (« exit clauses ») such as the case of force majeure. Restrictive provisions in contracts for which the consumer has little bargaining power (« responsibility contracts ») result in consumer protection control. Contracts are widespread in commercial law and form the legal basis for transactions worldwide. Contracts for the sale of goods and services (wholesale and detail), construction contracts, transport contracts, software licenses, employment contracts, insurance contracts, sale or lease of land, etc. As a general rule, courts are not in a position to balance the « proportionality » of the consideration, provided that the consideration is determined as « sufficient », the adequacy being defined as an exercise in legal review, while « adequacy » is subjective fairness or equivalence. For example, consent to the sale of a car for a pfennig may constitute a binding contract (although the transaction is an attempt to avoid taxes, it is treated by the tax authorities as if a market price had been paid).
 Parties may do so for tax purposes and attempt to conceal donations in the form of contracts.