Modern fantasy literature has used the Matter of France far less than the Matter of Britain, although L. Sprague de Camp and Fletcher Pratt set one of their Harold Shea stories ("The Castle of Iron") in the world of the Matter of France, and Poul Anderson's "Three Hearts and Three Lions" references the Matter of France. Through Anderson's book, the Matter of France also had some influence on the popular "Dungeons & Dragons" game. Italo Calvino's fantasy novel "The Nonexistent Knight" also takes place in this world.