Meanwhile, the Royal Shakespeare Company has just premiered its brand new stage play: Game of Thrones: The Mad King. Let's run through four major reveals that have come out of these first showings of Game of Thrones: The Mad King. | Photo Courtesy Royal Shakespeare Company (RSC)Is the Game of Thrones: The Mad King play canon? This means that Game of Thrones: The Mad King almost certainly contains material Martin considers canon. Game of Thrones: The Mad King is currently running at the Royal Shakespeare Theatre in Stratford-upon-Avon until September 26, 2026.