: Unlike traditional heroes, Berger's Arthur quickly realizes that a king is the least free man in his kingdom, a "captive of many laws" and prophecies that prevent him from ever acting on his own will.

: Berger portrays their relationship with explicit sexual imagery and tension. Guinevere is depicted as a pragmatic cynic who views men as children, while Launcelot is a virtuous but pained figure assigned by Arthur to the Queen's side—a selfless act by the King that ultimately shatters the "harmonious triangle" of Camelot.

The central thesis of Arthur Rex explores the tragic impossibility of absolute virtue in a flawed world. Berger’s Arthur is a noble idealist who creates the Round Table to channel the violence of his age into chivalry. However, the novel posits that this very "Might for Right" concept is doomed because it ignores the complexities of human nature.