“Crime fiction is a game with rules, an intellectual competition between writer and reader. To keep the game fair, both writer and reader must play by the same rules” (Miller). Some of the conventional rules of detective fiction are listed in S.S. Van Dine's "Twenty Rules for Writing Crime Stories" and Ronald Knox's "10 Commandments of Crime Fiction." However, some of the "rules" listed by Knox and Van Dine do not extend to Ruth Rendell's A Judgment in Stone and Agatha Christie's The Murder of Roger Ackroyd. Although Rendell and Christie do not conform to these "rules" of detective fiction established by Van Dine and Knox, their novels challenge the reader, create thrilling suspense, and, while unorthodox, are hugely successful. The most important of Ronald Knox Fiction's “10 Commandments of the Detective” is the first commandment: “The criminal must be someone mentioned in the first part of the story, but he must not be someone whose thoughts the reader is permitted to follow.” Rendell and Christie stick somewhat to Knox's first commandment and introduce the criminal at the beginning of their respective novels. However, both novelists defy Knox's commandment by allowing the reader access to the mind of the guilty criminal. Although Christie and Rendell allow access to the minds of criminals in two different ways, their access allows the reader to understand the minds of these criminals and allows them to see the events that took place from the criminal's point of view and understand them the reasons. each criminal committed their own crimes. This provides an interesting and exciting twist to the novel that would not be present if Christie and Rendell had conformed to Knox's first commandment. In The Murder of Roger Ackroyd, Ch...... middle of paper ......ority of the rules, and the ones they broke only lead to a more compelling story. Overall, while it might seem sacrilegious to ignore some of Van Dine's rules and Knox's commandments, both authors do so to create a novel that takes the reader by surprise. Works Cited Christie, Agatha. The Murder of Roger Ackroyd: A Hercule Poirot Mystery. New York:Harper, 2011. Print.Knox, Richard. “10 Commandments of Crime Fiction.” Miller, Susan Cummins. "Burning Paths, Redefining the Game; New Rules for Mystery Fiction with a Geoscientific Twist." Abstracts with programs - Geological Society of America 35.6 (2003): 20. ProQuest. Network. May 28, 2014. Rendell, Ruth. A sentence in stone. New York: Vintage Books, 2000. Print.Van Dine, S.S. “Twenty Rules for Writing Crime Novels.” Pantry. The English detective novel: EN 3178. York University. May 2014. Print.