Defenses.

Vitiating factors constituting defenses to purported contract formation include:

Mistake (such as non est factum).

Incapacity, including mental incompetence and infancy/minority.

Duress.

Undue influence.

 Unconscionability.

Misrepresentation or fraud.

Frustration of purpose.

Such defenses operate to determine whether a purported contract is either (1) void or (2) voidable. Void contracts cannot be ratified by either party. Voidable contracts can be ratified.

Misrepresentation.

Misrepresentation means a false statement of fact made by one party to another party and has the effect of inducing that party into the contract. For example, under certain circumstances, false statements or promises made by a seller of goods regarding the quality or nature of the product that the seller has may constitute misrepresentation. A finding of misrepresentation allows for a remedy of rescission and sometimes damages depending on the type of misrepresentation.

In a court of law, to prove misrepresentation and/or fraud, there must be evidence that shows a claim was made, said claim was false, the party making the claim knew the claim was false, and that party's intention was for a transaction to occur based upon the false claim.

There are two types of misrepresentation: fraud in the factum and fraud in inducement. Fraud in the factum focuses on whether the party alleging misrepresentation knew they were creating a contract. If the party did not know that they were entering into a contract, there is no meeting of the minds, and the contract is void. Fraud in inducement focuses on misrepresentation attempting to get the party to enter into the contract. Misrepresentation of a material fact (if the party knew the truth, that party would not have entered into the contract) makes a contract voidable.

Remedies for defendants on defenses.

Setting aside the contract.

To rescind is to set aside or unmake a contract. There are four different ways in which contracts can be set aside. A contract may be deemed 'void', 'voidable' or 'unenforceable', or declared 'ineffective'. Voidness implies that a contract never came into existence. Voidability implies that one or both parties may declare a contract ineffective at their wish. Kill fees are paid by magazine publishers to authors when their articles are submitted on time but are subsequently not used for publication. When this occurs, the magazine cannot claim copyright for the "killed" assignment. Unenforceability implies that neither party may have recourse to a court for a remedy.

Ineffectiveness arises when a contract is terminated by order of a court, where a public body has failed to satisfy the requirements of public procurement law. This remedy was created by the Public Contracts (Amendments) Regulations 2009.

Disputes.

Procedure.

In many countries, in order to obtain damages for breach of contract or to obtain specific performance or other equitable relief, the aggrieved injured party may file a civil (non-criminal) lawsuit in court.

In England and Wales, a contract may be enforced by use of a claim, or in urgent cases by applying for an interim injunction to prevent a breach. Likewise, in the United States, an aggrieved party may apply for injunctive relief to prevent a threatened breach of contract, where such breach would result in irreparable harm that could not be adequately remedied by money damages.