King (or its female equivalent "Queen") in the Ryccian Empire refers to an extraordinary non-hereditary title of nobility. It is only granted to those who have given a legendary service for the Empire. The last time this title was granted to any being was more than a thousand years ago, when the most outstanding Generals, Admirals and key civilian members of the democratic rebellion were granted such peerages.

The children of Kings and Queens become hereditary Imperial Princes upon the death of their distinguished parent, although this title can only be inherited by direct descendants. If a hereditary prince fails to have any heirs, their title officially becomes extinct. These princes are the only non-royals of their kind, and they are next in line for the throne after the titled members of the royal family despite not having any familial connections.