There are four main heading Anthropologists categorize rules of descent.

The tribes had their own kinship systems and rules of descent and inheritance.

However, as with illegitimate children where legitimated, such children have no rights to inheritance of peerages, although Scottish peerages rules of descent differ.

Situations like this are outside the normal rules of descent, and are dealt with by special decisions, guided by the International Commission of Botanical Nomenclature (ICBN).

Some very old titles, like the Earldom of Arlington, may pass to heirs of the body (not just heirs-male), these follow the same rules of descent as do baronies by writ and seem able to fall into abeyance as well.

Because of American Indian tribes' rules of descent and membership, European-American society's discrimination, and the distance that such mixed-race families lived from most European Americans, the children of unions between European fathers and certain Indian mothers were often left outside the social networks of both societies.