Ronald Knox’s 10 Commandments of Detective Fiction

Ronald Knox’s 10 Commandments of Detective Fiction

Hello everyone and welcome to the blog! Today, I want to talk about something I randomly stumbled upon while listening to an audiobook. I've never heard of Ronald Know or the 1o Commandments of Detective Fiction, but I want to bring awareness to this and discuss. So, let's get into it!

Ronald Knox was a mystery writer in the early part of the 20th century who belonged to the Detection Club, a society comprised of legendary mystery writers such as, Agatha Christie, Dorothy Sayers, etc. He was also a Catholic priest which is perhaps why he decided to call these rules his Commandments. The members of the society were supposed to follow these because they believed that the reader deserves a fighting change to solve the mystery without the author's use of cheap tricks. Below are the rules:

  1. The Criminal must be someone mentioned in the early part of the story but must not be anyone whose thoughts the reader has allowed to follow.
  2. All supernatural or preternatural agencies are ruled out as a matter of course.
  3. Not more than one secret room or passage is allowable.
  4. No hitherto undiscovered poisons may be used, nor any appliance which will need a long scientific explanation at the end.
  5. No Chinaman must figure in the story.
  6. No accident must ever help the detective, nor must he ever have an unaccountable intuition which proves to be right.
  7. The detective must not himself commit the crime.
  8. The detective must not light on any clues which are not instantly produced for the inspection of the reader.
  9. The stupid friend of the detective, the Watson, must not conceal any thoughts which pass through his mind; his intelligence must be slightly, but very slightly below that of the average reader.
  10. Twin brother, and doubles generally, must not appear unless we have been dully prepared for them.

While these Commandments do not all hold up to today's standards, they are still well-known. I feel like if we were to change things up to match the 21st century, the Commandments should be as follows:

  1. The criminal must be someone mentioned in the early part of the story, not a random character at the last second.
  2. No supernatural elements can be responsible for the dead of a character or involved in a crime in anyway.
  3. 1-3 plot twists allowed. Let's not go overboard.
  4. The crime needs to be realistic to the 21st century. No made-up poisons, no made-up illnesses, no conveniently placed weapons, etc.
  5. No redemption arc.
  6. Detective can have a hunch and/or intuition towards an event or person, but not so much so that he/she is exactly correct.
  7. The victim cannot commit the crime on themselves.
  8. There is room for the reader to make their own conclusions from the clues produced; there is not just one clear path for the reader to take.
  9. The "Watson" to the detective is there to benefit the reader.
  10. Avoid cliches.

I feel like these rules are fair. I personally hare when there is mention of ghosts or a supernatural presence in thrillers. It's not appealing and overall feels childish. Also, I love plot twists, but too many of them end up taking away from the story and the readers are often left confused. My redemption arc rule would only apply to the mystery/thriller rule. Any other genre, I wouldn't care about.

Some of Knox's rules I never would have thought of. For example, no more than one secret passageway or room, that's kind of funny. Or rule number why? These definitely need some updating. It kind of felt like I was rewriting the different circles of hell...look out Dante, you're next.  

Alright folks, that is all I have for this week! Come back next Wednesday for another blog post! As always, thank you for reading:)