In California, the capacity to contract is a fundamental legal requirement for a valid contract. Generally, individuals must have the mental ability to understand the nature and consequences of their actions when entering into a contract. According to California law, certain groups of individuals may lack the legal capacity to contract. These groups include minors (persons under 18 years of age), individuals who are mentally incapacitated, and those under the influence of drugs or alcohol to the extent that they cannot comprehend the terms and obligations of the agreement. Contracts entered into by such individuals are typically voidable, meaning that the individual may choose to enforce or rescind the contract, depending on the circumstances.
However, California law provides exceptions to this rule, particularly for contracts related to necessities such as food, shelter, and medical care. Minors, for example, may be bound by contracts involving these essential items. Additionally, contracts entered into by individuals who are mentally incapacitated may still be enforceable if the person had capacity at the time of contracting or if the contract was ratified after the individual regained mental competence. In the case of intoxication, a contract may be voidable if it can be proven that the person was unable to understand the nature of the contract due to their impaired state.