Skills differ in their principles of contractual freedom. In common law laws such as England and the United States, a high degree of freedom is the norm. In American law, for example, in the case of Hurley v. Eddingfield, the physician was allowed to refuse treatment to a patient, despite the lack of other medical care available and the subsequent death of the patient.  This runs counter to civil law, which generally applies certain cross-cutting principles to contract disputes, as in the French civil code. Other legal systems, such as Islamic law, socialist legal systems and customary law, have their own variations. Some arbitration clauses are unenforceable and, in other cases, arbitration may not be sufficient to resolve a dispute. For example, disputes over the validity of registered intellectual property rights may be settled by a public body within the national registration system.  In the case of matters of significant public interest that go beyond the narrow interests of the parties to the agreement, such as allegations that a party breached a contract by committing unlawful anti-competitive conduct or committing civil rights violations, a court may find that the parties may assert one or all of their rights before contracting out.  In India, electronic contracts are governed by the Indian Contracts Act (1872), under which certain conditions must be met when making a valid contact. Some sections of the Information Technology Act (2000) also provide for the validity of online contracts.
 It is advisable (if possible) to ensure that your business agreements are available in writing in order to avoid any problems when attempting to prove a contract. On the other hand, budgetary and social agreements such as those between children and parents are generally unenforceable on the basis of public order. For example, in the English case Balfour v. Balfour, a man agreed to give 30 dollars a month to his wife while he was not home, but the court refused to enforce the agreement when the husband stopped paying. On the other hand, in Merritt/Merritt, the Tribunal imposed an agreement between an insane couple, because the circumstances suggested that their agreement should have legal consequences. 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. 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.” While agreements between friends are acceptable for ordinary favors, contracts are a common practice in the economy. The contracts clearly show what each party has agreed, set deadlines and outline options for the application of the contract if the other party does not meet its obligations.