In my last post, I discussed Knox’s Commandments, a set of “fair play” rules that were written in the late 1920s and helped form much of the “golden era” of Cozy Mystery writing (then considered detective fiction). This time I’m going to go through some of the rules I think still retain relevance today and are worth discussing. Obviously, some of them have basically been discarded by the sands of time. (Again, I’m sorry that the rules are dated, and that some of them are phrased in a way that makes them uncomfortable to modern sensibilities.)
Rule 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.”
As with most of the “rules”, this is one that’s been broken before, occasionally to good effect. It’s still not generally recommended for less experienced authors since pulling it off without feeling unfair is quite difficult, but I wrote an earlier blog about authors such as Agatha Christie who were able to make it work.
Rule 2 – “All supernatural or preternatural agencies are ruled out as a matter of course.”
Of Knox’s Commandments, this is perhaps the rule most thoroughly discarded in modern Cozy Mysteries. Especially in recent years, there has been an increase in paranormal or supernaturally themed Cozies where criminal and detective alike have some sort of supernatural hook such as witchcraft or mild psychic powers. Simply summarily solving the crime through magic should probably still be avoided – just saying “the detective casts a spell and now knows who committed the crime” still shouldn’t happen.
Rule 4 – “No hitherto undiscovered poisons may be used, nor any appliance which will need a long scientific explanation at the end.”
By “undiscovered”, Knox means that the poison should be known to medical science, and if at all possible detectable by autopsy. I think this rule should be considered a good one – if the authorities bother to look carefully for a cause of death, an autopsy or similar test shouldn’t come back inconclusive. That said, poisons that make a murder look like something else to casual observation are still fair play, so long as the eventual cause of death can be determined to be murder in the end.
Rule 6 – “No accident must ever help the detective, nor must he ever have an unaccountable intuition which proves to be right.”
Knox clarifies that this isn’t intended to mean that the detective can’t have a flash of intuition where previously observed evidence suddenly makes the solution clear to him, but rather that he shouldn’t be able to, in Knox’s words, “to look for the lost will in the works of the grandfather clock because an unaccountable instinct tells him that that is the right place to search.” If the detective comes across the hidden will through hard work and dedication, such as by searching the entire house from top to bottom, that’s fine. This rule can sometimes be broken, especially if the detective is associated with the paranormal. For more mundane detectives, it should generally remain intact.
Rule 7 – “The detective must not himself commit the crime.”
I’d say this is an important rule, both today and when it was first written. It hardly seems fair for the detective to gather together all the suspects and then declare that it was in fact… himself! Knox also points out that this is only a solid rule when the author vouches for the character as a detective – a criminal posing as a police officer is still fair, especially if some reason to doubt their identity is introduced.
Rule 8 – “The detective must not light on any clues which are not instantly produced for the inspection of the reader.”
This rule has been broken before and will be broken again, but I personally think it’s unfair. If the crucial piece of evidence isn’t visible to the audience, it feels like the author is cheating and that the mystery simply isn’t solvable for the audience.
Rule 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.”
Knox also points out that this rule only applies if there is a “Watson”. I think this is a good rule to aim for, but harder to hit – writing an assistant as slightly below average intelligence is a tough goal for many authors.
Yikes! That sure was a lot of rules! It is a bit surprising how well many of the rules hold up – I guess what was fair to the reader when they were first written in the 1920s can still be generally considered fair today!
Which of the rules do you think are the most abused today? Do you think some of the rules I see as discarded haven’t been? What is your opinion about Knox’s (10) Commandments in today’s Cozy Mysteries? Are there other rules you think should be substituted for these? (For instance, I would suggest a rule where the sleuth doesn’t always fall into peril as part of the plot of every book in the series.)
Knox’s Commandments – The 10 Rules of Golden Age Detective Fiction, Part 1
Linda MH says
I love these posts, Danna. So fascinating! Thanks for bringing this info to my attention. I always learn so much from you!
Danna - cozy mystery list says
Linda MH, I’m glad you’re enjoying these Detection Club/Knox Commandments. I wasn’t sure about posting them…
susy says
I very much agree with your eleventh rule — sleuth must not be put in peril in each book! I hate that; makes the sleuth seem stupid. The last thing I want in my cozy is a stupid sleuth. Or one that is continually unlucky.
Danna - cozy mystery list says
Susy, I just this week dropped a favorite author of mine. I absolutely love the series, but when the sleuth became a new mystery, I decided that enough was enough. I had gone through the danger factor once too many times!
Greenway says
Oh! I’d miss too much otherwise-good mystery-“suspenders” if I didn’t just wry grin and sigh and let the rash heroes bumble in, again, where the not-dmfoo demur to tread. Just goes with the territory and works best if they’re humorous mysteries… Like “never learning” goes with (so often)”never aging” and always getting more away with housebreaking, injuries to themselves and others, not being shunned or “put away” for unauthorized investigations (corpse-finding, etc.) and so forth, among series heroes. They also seem to magically be thought to take care of their other vocations while spending almost all their time on this-episode mystery. M.C. Beaton’s Hamish MacBeth and Agatha Raisin had work and time within each book portrayed realistically, but they and their “familiars” never aged at all. That said, I really have always hated the limitless capacity of some protagonists (blame the writers!) for head trauma and being shot between the heart and the left collarbone without the death or permanent disability even one such injury would incur. And Stewart Kaminsky’s Toby Peters novels are, because of their so-many other charms, are the only “beating taker” books or TV shows I can stand– and usually, the heroes smart-mouth “Ask for it” too!
Anne says
I would amend rule 9 and say that characters shouldn’t be stupid beyond belief e.g. discovering the identity of a serial killer in the middle of the night and deciding to go to bed and phone the police in the morning. It always amazes me that so many plots depend on people keeping quiet about what they know or confronting a dangerous killer.
Would you? Not me!
Danna - cozy mystery list says
Anne, your twist on #9 is perfect! I would not put off telling the police until the morning, hoping that nothing happens during the night. The sleuth “keeping quiet” passes for an idiot plot!
Susan* says
Definitely what the romance people call ‘TSTL – Too Stupid To Live’. (You wonder they make it to the next book, sometimes.)
This is the mainstay of many a low-budget horror movie where the young heroine goes into the not-so-empty house / cellar / attic where the insane axe-murderer is lurking, because she’s heard a noise… (Cue dramatic music! Lol!)
There’s actually a very nice riff on this in Dorothy L. Sayers’ “Gaudy Night”. Harriet Vane has answered an unexpected summons late in the evening, and halfway there realises just how stupid she has been.
She then finds the nearest phone box and rings up her supposed summoner… One of my favourite Sayers novels, and very nicely done, imho.
Anne says
Well put Susan. (What does “imho” mean?)
Susan* says
Thankyou Anne. 🙂
Imho stands for In My Humble Opinion. Can also be IMO – In My Opinion.
Danna - cozy mystery list says
Susan*, I guess I should re-read Sayer’s Gaudy Night! When a sleuth is, as you say “TSTL” twice, that’s when I call it a day!
P.S. My daughter told me that Babadook (Australian thriller with Essie Davis – Miss Fischer!) was very good and truly scary!
Anne says
Cheers Susan; I learn something new every day!
Linda NB says
These posts are the best. I am truly enjoying them and the hard work you have put into the research is greatly appreciated. It is interesting to see the growth of this genre of writing and the changing of the rule as we move forward only makes sense. Thanks again for posting these,
Danna - cozy mystery list says
Linda NB, thank you! I’m glad you enjoyed them. You’re so right about us changing the rules. I’m guessing the original Detection Club would have never thought we would have such a strong paranormal sub-genre!
Julie says
What I liked about Agatha Christie and her sleuths is that they would collect the information from different sources and take the time to sort it out, sift through it and figure out who the killer is. They would then give the reader a chance to figure out the solution before gathering suspects at the end for the big reveal. I just finished a book by ***** (but there are many others) that had the sleuth question people and with each new suspect she went to accuse the person and that person would drop another suspect and she would be off to accuse the next one (again, alone) etc until every character has been accused and cleared at least once. With no real clues to follow. The sleuth stumbles around blindly and happens on the killer accidentally in the end. This is distracting. How many mysteries have you read that most of the clues and the solution are both revealed in the last few pages?
Love this topic!
On another note, my husband bought me “The Floating Admiral” for Christmas. Described as a collaboration of “Certain Members of the Detection Club”. I can’t wait to read it. I just have to many things going on to enjoy it right now.
Danna - cozy mystery list says
Julie, things like this annoy me also.
I just watched a television mystery movie where the sleuth received a piece of pertinent information at the very end of the movie. She was passed this big clue while she had everyone gathered, right before she told everyone (including the police in charge!) who the murderer was. The detective asked her to share the information she had just received, to which she replied something like “In a minute.” Yikes! Since the audience finally received this very important information right in the last five minutes of the show, I felt cheated. Good grief!
Martha Knox (Marty Knox) says
Agatha Christie wrote about Inspector Slack who is given a clue Body in the Library, which he ignores because he is rude and supercilious towards people, And in Murder at the Vicarage when the absent-minded vicar tries to tell Slack the clocks are set ahead so the vicar won’t be late.
In my series of mysteries, the head law officer is a Luddite who abhors computers, and because of that a villain almost gets away with murder, my clever compute-forensic detective is hired to do the grunt work on a pre-1990s disappearance where all the clues are B.I. (Before the Interenet). too twisty.
Debbi says
A lot of these sound like Sherlock Holmes to me, and not just #9. I think #4, 6, 8 and of course #9. But I agree with most of what you said. I also like to try to solve the mystery with the author. I just read one where the solving was finished quickly, and it was only solved by chance at the end (the murderer was in the wrong place at the wrong time, just trying to cover up his crime that no one had solved anyway) and to top it off, the police had been called for some other incident and so they happen to be there to arrest the murderer.
By the way, I love this site. All cozies in one place. Thank you for doing this!
Danna - cozy mystery list says
Debbi, your example would have made me drop that author, even if she/he was a favorite author of mine! “Idiot plot!”
I am so glad you are enjoying the site. We have a great group of Cozy Mystery readers who comment over here! (I wanted to use “commenters” but I’m not sure that’s a word!)
Maria (BearMountainBooks) says
Oh, I like it when the friend or assistant is just as intelligent as the main! I know that Watson was kind of the “foil” to Sherlock, but I don’t think that the side-kick can’t have his own triumphs going too. I think this is especially important if the side-kick is a love interest. I love it when an author develops side characters as much as the main and when they can sometimes take on a starring role.
I’m also glad that the paranormal element is showing up in more cozies today. I enjoy them a lot.
Danna - cozy mystery list says
Maria, hmmm… I’m going to have to re-read some Sherlock Holmes stories.
Martha Knox (Marty Knox) says
I agree with most of Knox’s Rules, but I think Agatha Christie delightedly thumbed her nose at all of them. The murderer as the protagonist, a Chinaman, twins (Pip and Emma, Lottie and Lettie). a girl too stupid-abc murders Betty, the Blue Train), broken fingernails, secret passages, weird poisons, and more. I have read every book at least three or four times, watched many editions of Miss Marple, and Poirot, and I still delight every time because once I know the culprit, I love to search for the twists. Someday on my bucket list is to visit bath and Torquay.
J. F. Benedetto says
Rule 5 — “No Chinaman must figure in the story.”
The reason this was included was that by the time Father Knox wrote the list, it was a trope to fall back on a stereotypical Chinese as the bad guy, and it became a weak (but common!) go-to to always use “an inscrutable Chinaman” as the evil villain. In modern terms, it would be like saying “Rule 5 — Do NOT end any story with “The butler did it!”