Full disclosure, the six rules of writing mysteries were set forth by A.A. Milne, who wrote Winnie the Pooh, but Milne does speak for Winnie, so there.
Milne also wrote a delightful mystery The Red House Mystery, that he dedicated to his father who was a big fan of mysteries.
So the six rules:
- The story should be written in good English
I thought that would be a given. After all, if you write bad English, you write a bad novel. So writing in good English should be obvious. I think this rule came from Winnie and Milne used to make Winnie happy.
2. Love interest is undesirable.
Raymond Chandler also said the same thing. Of course there was Nick and Nora Charles, but being married their love is implicit. They sparred with wit and charm, with Nora being Watson to Nick’s Sherlock, although she was smarter than Watson.
Chandler, by the way, thought little of Milne’s mystery. He also trashed Agatha Christie, Dorothy L. Sayers and virtually all British mystery novelists in the Golden Age of British mysteries, between the two world wars. Chandler was about realism, especially the writings of Dashiell Hammett. But Chandler missed elements of Red House Mystery, those being social satire, with a stab at comedy of manners. It is very witty with sharp dialogue.
3. Both detective and villain should be amateurs.
Since the early 1920’s, when Milne was writing these rules, police procedural mysteries have become a sub genre of their own. There were a few back then, but the genre has grown to the point that this rule does not apply. It is a matter of taste and preference and I prefer the amateur.
4. Scientific detection is ‘too easy’.
I am not sure what Milne meant with this rule. But obviously nearly a century has passed and science is much bigger now in detecting clues and evidence. British mysteries in the golden age were more about puzzles, and figuring out who did it. Milne may have implied that the amateur detective should rely on getting clues, piecing them together to solve the puzzle.
5. The reader must know as much as the detective.
This rule should apply to all mysteries of any era. The reader should have access to the information, not only to see if he can solve the murder before the end, but more important, not to trick the reader. You can not add information at the end when the killer is revealed that comes as a surprise to the reader. That is not playing fair and it pisses off the reader who has invested his time in the story.
6. There should be a Watson: it is better for the detective to Watsonize’ than soliloquize.
This is elementary. One could have a detective working alone and he can share his thoughts through the first person, such as “When I saw the gun on the floor it was too far away for it to be suicide, but then why was the gun ten feet away, perhaps because . . .” In essence the reader could be the Watson. In my mysteries I use Chet and Eveleen, a married couple, who along with their flapper friend Clancy solve mysteries. I do this because I enjoy their interplay.