Contract law works best when an agreement is reached, and recourse to the courts is never necessary because each party knows its rights and obligations. However, where an unforeseen event makes an agreement very difficult, if not impossible, the courts will generally consider that the parties wish to break their obligations. It may also be that a party simply violates the terms of the contract. When a contract is not executed in substance, the innocent person has the right to terminate his own benefits and to sue for damages in order to allow him to put himself in a situation, as if the contract had been executed. They are required to reduce their own losses and cannot claim prejudice that was a distant consequence of the offence, but remedies under English law are based on the principle that full compensation for all losses, not or not, must be repaired. In exceptional cases, the law continues to require a criminal to replace the benefits of breaching a contract and may require a specific execution of the agreement instead of financial compensation. It is also possible that a contract will be cancelled because a party has not advertised adequately based on the nature of the contract or has provided false information during the negotiations. During the Industrial Revolution, English courts became increasingly entangled in the notion of “contractual freedom.” This was partly a sign of progress, since the remnants of feudal and commercial restrictions for workers and businesses were removed, a move of people (at least theoretically) from “status to contract”.  On the other hand, a preference for laissez-faire ideas was the unequal bargaining power in several contracts, particularly for employment, consumer goods and services and leases.
At the centre of the General Treaty Act, captured in rhymes such as Robert Browning`s rat hunter of Hameln in 1842, was the legendary idea that if people had promised something, “keep our promise.”  But then the law claimed to cover any form of agreement, as if everyone had the same free will to promise what he wanted. Although many of the most influential Liberal thinkers, particularly John Stuart Mill, believed with several exceptions to the rule that letting him do so was the best policy, the courts were wary of interfering in agreements, regardless of party. In Printing and Numerical Registering Co v Sampson, Sir George Jessel MR declared a “public policy” that “free and voluntary contracts are sacred and enforced by the courts.”  In the same year, the 1875 Justice Act merged the registry courts and the common law, always favouring just principles (such as Estoppel, inappropriate influence, resignation for misrepresentation and loyalty or disclosure obligations in certain transactions).  A related doctrine is a “common error” which, since Lord Phillips MR`s decision in The Great Peace, is much the same as frustration, except that the event that makes it impossible to execute a contract takes place before and after the conclusion of a contract.  A “common error” differs from “mistakes” that occur between offer and acceptance (i.e., there is no agreement at all) or so-called “identity” cases resulting from fraudulent misrepresentation (which generally invalidates a contract, does not invalidate it, unless it is concluded in a written and remote document) because it is based on the seriously difficult performance to achieve. For example, at Courturier v Hastie, a shipment of corn had elapsed when two businessmen had entered into a contract, so it was established (perhaps controversial) that the seller was not responsible because it was still physically impossible.