This is called the peppercorn rule, but in some jurisdictions, the penny may be a legally insufficient nominal consideration. An exception to the adequacy rule is money, a debt of “compliance and satisfaction” that must always be paid in full.     Legal systems differ in the use of “agreement” to refer to a legally enforceable contract. For example, the Washington Supreme Court has found that a treaty is a promise or series of promises protected by law, while an agreement is a manifestation of mutual consent that does not necessarily have legal implications. However, in Pennsylvania, an agreement has been defined as an enforceable contract in which the parties intend to enter into a binding agreement. However, the essential elements of the agreement must be sufficiently secure to serve as a basis for determining whether there is an infringement. Subsequently, the parties must prove their mutual consent. If one of the parties has been coerced or forced into the contract, there is no mutual agreement and the contract is not legally binding or enforceable. Finally, the parties must prove that they are both legally fit.
If, at the time of signing the contract, the parties are under 18 years of age, are mentally incompetent or under the influence of drugs or alcohol, the parties are not considered legally fit. Each country recognized by national law has its own national legal system governing contracts. While contract law systems may have similarities, they may differ considerably. As a result, many contracts include a legal choice clause and a jurisdiction clause. These provisions define the laws of the country that governs the treaty and the country or other forum where disputes are settled. If the treaty itself does not provide for explicit agreement on such matters, countries have rules to define the law applicable to the treaty and jurisdiction over litigation. . . .