Intoxication can impair a person's judgment and decision-making abilities, potentially rendering them incapable of entering into a valid contract.

In many jurisdictions, the age of majority is 18 years old, at which point individuals are considered legally competent to enter into contracts.

A person's capacity to contract can be affected by various factors, including age, mental competence, and intoxication.

Contracts entered into by individuals lacking the capacity to contract are typically considered voidable, meaning they can be canceled or annulled by the party lacking capacity.

In some jurisdictions, individuals with mental illnesses may be considered to have the capacity to contract during periods of lucidity, when their mental faculties are clear and they are capable of understanding the nature and consequences of the contract.

Duress is not a defense to a claim of incapacity to contract because it does not negate the individual's lack of capacity to understand the nature and consequences of the contract.

Contracts entered into by minors are typically considered voidable, meaning they can be canceled or annulled by the minor or their legal guardian.

The doctrine of unconscionability protects individuals from entering into contracts that are grossly unfair or one-sided, even if the individual had the capacity to contract.

The presence of a written contract is not a factor that courts consider when determining whether a contract is unconscionable.

Contracts entered into under the influence of alcohol, drugs, or both are generally considered to be voidable due to the individual's impaired judgment and decision-making abilities.

Specific performance is not a remedy available to a party who has entered into a contract with an individual lacking the capacity to contract because it requires the party lacking capacity to perform the obligations of the contract.

In some jurisdictions, an individual who enters into a contract while intoxicated may be able to avoid the contract if they can prove that they were completely unaware of the nature and consequences of the contract due to their intoxication.

Alienage, or the status of being a foreign national, is not a type of incapacity that can affect a person's ability to enter into a contract.

Contracts entered into by individuals under the influence of drugs are typically considered voidable, meaning they can be canceled or annulled by the party under the influence of drugs.

The legal doctrine that allows a party to avoid a contract due to a mistake of fact is known as the doctrine of mistake.