Any adult person of sound mind and good character may be appointed a guardian, except a married woman (without the consent of her husband), at common law and in some states.

A guardian may be appointed for a minor, for an insane person and sometimes for a spendthrift. A guardian will be appointed for any person who is so far from being in his right mind that he is unable to take proper care either of his person or his property. Such appointment will be made by the court having proper jurisdiction.

A guardian for an infant may be appointed either by the father in his will (but in Illinois, such appointment will not be allowed to defeat the mother's right to be appointed guardian if she is a proper person for the position); by decree of court having proper jurisdiction; or by the infant himself when above the age of fourteen years. Such appointment by the infant himself, however, will be subject to the approval of the court in order to protect the infant from the consequences of an improper choice.