An agreement is usually an informal, often unwritten, agreement between two or more parties. The parties simply agree to do or refrain from doing something. There is nothing to ask the parties to respect the terms of the agreement, other than the honour system. Both parties must be “reasonable” to understand the seriousness of the situation and understand what is necessary. This definition requires that neither party be minor, both must be sober (not under the influence of drugs or alcohol when signing the contract) and no rehabilitation can be mentally deficient. If a party is not competent, the contract is not valid and the unmarried party may refuse (ignore) the contract. To be exact, a legally enforceable agreement is called on the facts or no contract. A contract must contain the following elements: offer and acceptance, reasonable and unconditional consideration, free consent, capacity, legitimate purpose, security, intention to create legal obligations, and the agreement should not be declared null and void. Duress has been defined as a “threat of harm that is made to force a person to do something against his will or judgment; esp., an illegitimate threat made by one person to force a manifestation of another person`s apparent consent to a transaction without real will.  An example is Barton v Armstrong  in a person who has been threatened with death if he does not sign the treaty. An innocent party wishing to impose a contract of coercion on the person only has to prove that the threat was made and that it was one of the reasons for entering the contract; the burden of proof then rests with the other party to prove that the threat had no effect on the performance of the contract by the party.
There may also be constraints on goods and sometimes “economic constraints.” Inefficiency occurs when a contract is terminated by order of a court, when a public body has failed to meet the requirements of public procurement law. This remedy was created by the Public Procurement Regulations (Amendments) 2009 (SI 2009/2992). It was not possible to sue the Crown in the United Kingdom until 1948 for breach of contract. However, it was felt that the contractors might be reluctant to act on such a basis and the claims were maintained as part of a legal petition that had to be approved by the Minister of the Interior and the Attorney General. S.1 Crown Proceedings Act 1947 opened the crown to ordinary contractual claims by the courts as for any other person. It is important to note that contracts, such as agreements, should not be written unless they are for real estate transactions, marriage or more than one year, depending on the state. However, it is best to get written contracts, so you can go to court if a party does not meet its obligations. TIP: In almost all cases of creative work (z.B. a logo you pay for designing it), copyright remains the responsibility of the author, whether or not it was created on your behalf. If you use a contractor to manufacture copyrighted material, make sure that the contract involves the transfer of these protections, so that you own all the rights to the materials you paid for. The German marriage contract, in 1521 between Gottfried Werner von Zimmer and Apollonia of Henneberg-Rumhild, is very important.