Accession of a queen regnant occurs as a nation's order of succession permits. Methods of succession to kingdoms, tribal chiefships, and such include nomination (the reigning monarch or a council names an heir), primogeniture (in which the children of a monarch or chief have preference in order of birth from eldest to youngest), and ultimogeniture (in which the children have preference in the reverse order of birth from youngest to eldest). The scope of succession may be matrilineal, patrilineal, or both; or, rarely, open to general election when necessary. The right of succession may be open to men and women, or limited to men only or to women only.