Oklahoma Lack of Capacity (OLD) is a legal doctrine which states that a person does not have the mental capacity to enter into a contract or to be responsible for their own actions. This doctrine is used in civil cases in the state of Oklahoma when a person is unable to understand the nature of their actions or is unable to make reasoned decisions. Types of Oklahoma Lack of Capacity include mental incapacity, physical incapacity, and infancy. Mental incapacity includes being declared legally insane, having a mental illness, or being unable to understand the nature of one's actions due to age or cognitive impairment. Physical incapacity includes being physically disabled or unable to understand the nature of one's actions due to physical limitations. Infancy refers to a person under the age of 18 who is unable to understand the nature of their actions.