If the contractual terms are uncertain or incomplete, the parties do not reach an agreement in the eyes of the law.  An agreement is not a contract and the inability to agree on key issues that may include price or security elements may lead to the failure of the entire contract. However, a court will endeavour to implement commercial contracts where possible by excluding an appropriate design of the contract.  In New South Wales, even if a contract is uncertain or incomplete, the contract may remain binding on the parties if a sufficiently secure and comprehensive clause requires the parties to submit to arbitration, negotiation or mediation.  A contract with a guarantee must be written. A guarantee is an agreement by which a party agrees to repay the debts of another person or company in the event of a delay in the debt of the third party. In addition, contracts relating to the sale, transfer, option or lease of land should always be concluded in writing, as these are required by different third parties, including those that are spelled by future transactions, the land registry and where the granting of the estate is necessary. Written contracts are also required for the transfer or licensing of certain intellectual property rights. A contract is a legally binding document between at least two parties, which defines and regulates the rights and obligations of the parties to an agreement.  A contract is legally enforceable because it complies with the requirements and approval of the law. A contract usually involves the exchange of goods, services, money or promises from one of them. „breach of contract“ means that the law must grant the victim either access to remedies, such as damages, or annulment.
 The definition of a contract (contract) is as follows: a contractual clause is „a provision that is part of a contract.“  Any clause gives rise to a contractual obligation, the violation of which may give rise to litigation. Not all conditions are explicitly specified and certain conditions have less legal weight, as they are marginal in the treaty`s objectives.  Less often are unilateral treaties in which one party makes a promise, but the other party promises nothing. In these cases, those who accept the offer are not obliged to disclose their consent to the supplier. In a reward contract, for example, a person who has lost a dog could promise a reward if the dog is found through publication or oral. The payment could be packaged in addition if the dog is made alive. Those who learn the reward are not obliged to look for the dog, but if someone finds and delivers the dog, the promisor is required to pay.