Performance varies depending on the circumstances. When a contract is executed, it is called a performance contract and, when it is concluded, it is an executed contract. In some cases, this may be a significant benefit, but not a full benefit, which allows the exporting party to be partially compensated. In England and Wales, a contract can be obtained through the use of a right or, in an emergency, by an application for an injunction to prevent an infringement. Similarly, an aggrieved party in the United States may seek injunctions to avoid an imminent offence if such an offence results in irreparable harm that could not be properly repaired by criminal damage.  It was recently recognized that there was a third category, restitution obligations, based on the undue enrichment of the defendant at the plaintiff`s expense. Contractual liability, which reflects the constitutive function of the contract, is generally for failure to do things better (by unsurented benefit), liability in the unlawful act is generally aggravated for measures (as opposed to omission) things, and liability in restitution is for the unjustified taking or maintenance of the benefits of the plaintiff`s money or work.  In the United Kingdom, the breach of the 1977 Unfair Contract Act is defined as: [i] non-performance, [ii] poor performance, [iii] partial performance or [iv] performance substantially different from what was reasonably expected. Innocent parties may refuse the contract only because of a serious offence (violation of the condition), , but they may at any time recover replacement damages, provided the violation has caused foreseeable damage. Each country recognized by private international law has its own national legal system to govern treaties. While contract law systems may have similarities, they can differ significantly. As a result, many contracts contain a choice of law clause and a jurisdiction clause.
These provisions define the laws of the contracting country and the country or other forum in which disputes are settled.