An error is a misunderstanding of one or more parties and can be invoked as a reason for the invalidity of the agreement. The Common Law has identified three types of errors in the treaty: frequent errors, reciprocal errors and unilateral errors. If the contractual conditions are uncertain or incomplete, the parties cannot have reached an agreement in the eyes of the law.  An agreement does not constitute a contract and failure to agree on key issues that may include issues such as price or safety can lead to the failure of the entire contract. However, a court will endeavour, to the extent possible, to permit commercial agreements by interpreting an appropriate design of the contract.  In New South Wales, even if a contract is uncertain or incomplete, the contract may be binding on the parties if there is a sufficiently secure and comprehensive clause requiring the parties to submit to arbitration, negotiation or mediation.  Courts will generally not assess the „suitability“ of the consideration, provided that the consideration is considered „sufficient“, with adequacy defined as meeting the legal test, while „adequacy“ is subjective fairness or equivalence. For example, the authorization to sell a car for a penny may constitute a binding contract (although the transaction, when it comes to an attempt to avoid taxes, is treated by the tax authorities as if a market price had been paid).  The parties may do so for tax purposes in order to camouflage gift transactions as contracts. 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.     In the tradition of civil law, contract law is a branch of the law of obligations.  To obtain damages, an applicant must prove that the offence caused foreseeable harm.
  Hadley/Baxendale found that the control of predictability is both objective and subjective. . . .