Do Ronald Knox’s 1929 Rules on Detective Fiction Still Hold Up in 2020?

(With May Of Mystery right around the corner, I’ve decided to repost this article for last year. Enjoy!)

Hello my amateur sleuths!

Did you know that one famous author actually wrote rules for writing detective stories in the 1920’s?

Ronald Knox was a prominent figure in the Golden Age of Detective Fiction. As a mystery loving priest, he published the Ten Commandments on Detective Fiction. Are the rules still relevant or outdated? Let’s investigate, shall we?

1.The criminal must be someone mentioned in the early part of the story, but must not be anyone whose thoughts the reader has been allowed to follow.

True enough. If the author introduces the real killer towards the end, readers will feel cheated. How can they suspect a character that came out of nowhere? The criminal needs to be introduced within the first couple chapters of the story. Also, the audience, usually, isn’t allowed to enter the thoughts of the murderer. Their inner workings should remain unknown to the audience, until the very end.

2. All supernatural or preternatural agencies are ruled out as a matter of course.

Now, I disagree with this one, just a smidge. If done right, multiple genres can be featured in a single story. Maybe a sprinkle of supernatural could work in a murder mystery. It’s all about balance. As long as the integrity of the whodunit remains solid, other genres can join in. A little fantasy and magic never killed nobody.

3. Not more than one secret room or passage is allowable.

I mean, he has a point. A second secret passage won’t garner as much surprise as the first secret passage. One hidden room is enough. Don’t push your luck.

4. No hitherto undiscovered poisons may be used, nor any appliance which will need a long scientific explanation at the end.

Fair enough, Mr. Knox. Basically, this rule applies to all made up devices. Hard to acquire poisons from foreign lands or complex inventions are far too unlikely plotwise. Using an unusual method cheats the readers from unraveling the mystery themselves. Remember, detective fiction is meant to challenge the reader mentally, like a puzzle.

5. No Chinaman must figure in the story.

No, we’re not talking about those of Chinese descent. The term ‘Chinamen’ refers to evil mastermind character, maniacal laugh included. Antagonists need real motives. Their reason for committing a crime must be plausible. No sinister villains are welcome in a detective story.

6. No accident must ever help the detective, nor must he ever have an unaccountable intuition which proves to be right.

Frankly, this rule reminds me of those classic Scooby Doo cartoon, where clues fall into their laps. As tempting as it sounds, coincidences, chance happenings and bizarre hunches are just too easy. Every clue must be discovered on purpose, with purpose. Don’t just hand over clues on a silver platter. Make your detective, and the reader, work for every scrap of information.

7. The detective must not himself commit the crime.

Where’s the fun in that? Listen to Knox, it’d be a disaster to have the detective be the culprit. Plus, you’re killing any chance for a sequel. No pun intended.

8. The detective must not light on any clues which are not instantly produced for the inspection of the reader.

For fairness, the detective and the reader must have equal opportunity to solve the case. However, the sleuth can keep some less obvious clues to himself. Just collecting the insignificant clues in his/her pocket until the big reveal. The reader knows every hint, but just isn’t sure how important each piece of information is.

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.

I object to this one. Although he wasn’t smarter than Holmes, I wouldn’t consider Watson an idiot. Seriously, Watson could pull his own weight. The sidekick can have brains too. Heck, they may even become as asset for a detective during an investigation. Instead of being slightly below the reader’s intelligence, why can’t a sidekick’s intelligence be slightly below the detective’s brainpower?

10. Twin brothers, and doubles generally, must not appear unless we have been duly prepared for them.

See, I feel like nowadays, audiences are thrilled by surprise doubles. Not all doubles or twin need a heads up in advance. (Side note: Have you guys been watching Cloak and Dagger? Talk about shocking doubles.)

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Yes, all of these “commandments” have been broken in detective fiction before. However, some of these rules are still relevant by today’s standards. Murder mysteries are complicated games, whether you choose to take note of the rules or break them is up to you. You’re the writer.

What do you guys think of Knox’s rules from 1929? Do you think they still hold up to today’s whodunits? Let me know in the comments.

Write with Heart,

Lady Jabberwocky