Man-At-Arms is a scientist and inventor as well as loyal bodyguard to King Randor and Queen Marlena, rulers of Eternia. Man-At-Arms is also one of the few people who knows that He-Man's secret identity is that of Prince Adam, son of Randor and Marlena. To his close friends and associates, Man-At-Arms goes by the name of Duncan. Teela, captain of the Eternian royal guard, is Man-At-Arms' adopted daughter. Duncan frequently encounters mishaps and other pratfalls (such as levitating eggs falling on his head) due to the lackadaisical magic tricks of the court magician Orko.