Mysteries: Rules of the Genre


Vision 9

Mysteries: Rules of the Genre


Kay House

Copyright © 2002, Kay House, All Rights Reserved

Dorothy L. Sayers and the Detection Club wrote the rules that now define mystery and detective fiction.  Other authors, among them S. S. Van Dine,[i] proposed their own sets of rules, but the Detection Club rules were unusually good.  They struck an elegant balance between intellectual integrity and artistic license.  This, combined with the prominence of the Detection Club members as crime authors, appears to have made them the defining force of the genre.

Hercule Poirot, Father Brown, and Lord Peter Wimsey all owe their existence to Detection Club members.  Wimsey, of course, is Sayers' creation.  Hercule Poirot came from the fertile mind of Agatha Christie, and G. K. Chesterton wrote the Father Brown mysteries.  Sayers and Chesterton wrote detective stories to support their more scholarly work.  Agatha Christie reigned as the queen of crime fiction for more than twenty years.  Despite the fact that their mysteries fell into the mystery sub-genre now called "cozies,"[ii] their combined eminence, together with the support of the rest of the club, established a pattern for the entire mystery and detection genre. 

In 1928, the Roaring Twenties were nearing an end.  World War I was over, and the Great Depression was not yet in sight.  Writer Anthony Berkeley[iii] felt a need to socialize and talk shop with other detective writers.  He suggested to Sayers, Christie, Chesterton, and others that they and other crime writers dine together from time to time, and these meetings became regular.[iv]  By 1930,[v] the meetings had become the Detection Club, and the effects of the Great Depression had begun to make themselves felt worldwide.  The Detection Club started publishing collaborative works to raise money for their meeting place.  The first of these, Behind the Screen, was a radio serial.  It aired in the summer of 1930.

Sayers appears to have drafted the Detective Club's initiation ceremony.[vi] During the ceremony, new members take oath that they will abide by the club's rules for detective fiction.  All four rules are included in the oath.  First, detectives must solve their cases by using their wits.  (Authors must refrain from using divine revelation, coincidence, and the like.)  Second, the oath forbids concealing any vital clue from the reader.  Third, authors promise that gangs, super-criminals, trap doors, and similar contrivances will be used only with "seemly moderation."  Finally, poisons unknown to science are forbidden.[vii]  Club members apparently took the rules fairly seriously.  Sayers' draft wished pages swarming with misprints and continually diminishing sales on those who broke faith.[viii]

Despite the horrible punishments wished upon violators, the Club's rules were far less restrictive than those proposed by S. S. Van Dine.[ix]  He listed twenty rules, including an absolute ban on love interests.  Van Dine insisted on a solo detective -- no partnerships allowed.  He mandated murder as the only crime worth the reader's time, and forbade the use of servants and career criminals as perpetrators.  Van Dine also considered it cheating if an apparent murder turned out to be suicide.  Professor Mary Ann Gillies of Simon Fraser University[x] lists Van Dine's rules at

Members of the Detection Club wrote many successful mysteries in which they broke one or more of Van Dine's rules.  One story turns out to have been narrated by the murderer.  Another mystery has no murder in it anywhere.  One apparent murder turns out to have been a suicide.  Two or more detectives working in tandem solve several mysteries by Detection Club members.  Van Dine's rules are somewhat redundant, and the degree to which Detection Club members violated them with impunity is flagrant enough to incite speculation about a possible rivalry, or at least a touch of humor.  (In each of the two years before Van Dine's rules were published, at least one Detection Club member published a story that violated "the rules according to Van Dine.")

Two rules of mystery and detective fiction are so obvious that they are seldom stated.  First, some mystery or puzzle must hamper the resolution of the story's central conflict.  The second rule applies to the entire broad genre of fictional mystery, detection, and suspense: justice must prevail in the end. 

First: no puzzle, no mystery.  The puzzle must be as essential to the mystery or detective story as the speculative element is to science fiction and fantasy.  If you could give away the answer to the puzzle on the first page and still have a story left, it wouldn't be a mystery.  It might be a good story, but it would no more be a mystery than replacing six guns with laser blasters can convert a western into science fiction. 

To differentiate the mystery from another kind of suspense story, try the spy story.  Here, there may be no puzzle at all; the element of suspense may come only from "what happens next?"  In the spy story we usually know that the enemy consists of one or more nations or criminal groups who want to steal the secret, expose the secret, stop the defection, or keep the secret from the main character.  The conflict arises from the opposing aims of the known enemies, and the reader continues to turn the page to find out how the forces of justice prevail.

In a mystery story, the puzzle takes center stage.  The protagonist's ability to resolve the main conflict must be hampered by missing information.  In a mystery, the main character resolves the central conflict by discovering the missing information -- usually by whom, how, and why something was done.  In Ngaio Marsh's Artists in Crime,[xi] as in many other mysteries, the puzzle is "who killed the victim."  That is not, however, the only possible puzzle for a mystery.  Take, for example, Marsh's Death in a White Tie.[xii]  The central puzzle is not "how does the detective bring a murderer to justice," but rather, "how can the detective stop a blackmailer whose identity is unknown?"

Second, in every story that fits into the mystery or suspense genre, justice must prevail in the end.  The secret in a spy story need not come into the hands of the protagonist's country, but neither may it fall into the hands of its enemies.  The spy or the detective may die, but the perpetrator must not escape justice.  Justice need not be administered in court.  The case need not end with an arrest, but the reader must know the solution to the puzzle, and the justice, whether administered privately or publicly, must seem reasonably satisfying to the reader.  Satisfaction here has two aspects: the amends or punishment must be sufficient, and it must be, at least substantially, brought about by the efforts of the detective(s).  If the reader feels that the perpetrator "got away with it," then the story may have been a great story, but it was not a mystery.  If the reader feels that the resolution happened as a result of events outside the detective's control, the reader feels powerless and cheated.  Mysteries promise their readers that justice exists, and that they have some power to keep things that way.

Finally, one of the items listed in both the Detection Club's rules and Van Dine's rules requires emphasis and explanation.  No essential clue may be withheld from the reader. 

For example, before Sherlock Holmes deduces that Watson has come from Afghanistan, the author must provide all the clues Holmes observes.  The story must say that Watson's face is browned and his wrists pale, that one of his arms is held stiffly, that his face looks drawn, and that his behavior has a military air.[xiii]  The author can expect readers to recognize that the likeliest explanation for a dark face and pale wrists is a suntan on the face.  The author can expect readers to realize that this tan pattern is likely to be result from working outdoors in the tropics or in the summer.  The author may assume that the reader can look it up if she or he does not know when British Army was engaged in Afghanistan.  The stiff arm, haggard face and military bearing must not be omitted.  If they are, the reader feels cheated when Holmes says, condescendingly, "Elementary, my dear Watson."[xiv] 

Mystery fans don't mind a spice of romance, a detective partnership, or an old plot device used in an original way.  Many mystery fans are perfectly happy if a mystery also qualifies as speculative fiction in any of its sub-genres.  Most of them will enjoy exotic locations and historical settings, but nearly all of them are reading partly for the fun of trying to solve the puzzle before the detective explains it.  Old Ellery Queen books typically had the last chapter or two sealed, with a notice on the front of the sealed section that the reader had now been given all the clues.  Many mystery fans are quite capable of beating the detective to the solution, and they legitimately expect the author to play fair in the intellectual game of providing the puzzle and explaining how their detective solved it.

So, taking the written with the unwritten and combining two into one, we now have five rules of the genre for writing mystery and detective fiction.

  1. 1-     The solution of some mystery or puzzle must be necessary in order to resolve the central conflict.
  2. 2-     The detective(s) must use only their wits and skills to solve the puzzle, and these wits and skills must believable in the context of the story.
  3. 3-     No clue that is important to the solution of the puzzle may be concealed from the reader.
  4. 4-     Unusual and improbable circumstances, such as super criminals, obscure poisons, crime rings, secret entrances, coincidences and the like, must be used infrequently and skillfully enough to be believable in the context of the story; and finally,
  5. 5-     Justice must, in one fashion or another, be brought about by the action of the detective(s). 


[i] S. S. Van Dine was the pen name of Willard Huntington Wright.

[ii] "Cozies" give the reader a "cozy," comfortable sort of feel, whether they are set in a small town or upper crust London.  They are distinct in tone from the seedier feel of many professional private detective stories.  The detective need not be an amateur, but the gritty atmosphere of the Raymond Chandler "slumming angel" is absent.  Rita Mae Brown's mysteries are "cozies;" Sue Grafton's and Sarah Paretsky's are not.  Rex Stout's work probably occupies the line between.  Within the brownstone, all is cozy; outside, Archie (and occasionally Wolfe) deal with the harsher realities of life.

[iii] Berkeley typically wrote under pen names, and is the author of Malice Aforethought, Jugged Journalism, Before the Fact, and The Poisoned Chocolates Case, among other works.  Much of Berkeley's work is out of print at present, but copies are available through used book networks.

[iv] Brabazon, p. 143.

[v] The website of Professor Sarah J. Greenwald was tremendously helpful.  It includes a page on the Detection Club's publications (, which, taken together with the Brabazon biography and Professor Gillies' web page (see note 7 below) enabled me to piece together the probable evolution of the Detection Club from an informal dinner group to an established club.  Professor Greenwald's discussion of the questions surrounding the date of the club's establishment was crucial to this effort.  Greenwald is an Assistant Professor of Mathematics at Appalachian State University in Boone, North Carolina.  Her primary research interest is Reimannian geometry.

[vi] James Brabazon notes on page 144 of his authorized biography of Sayers, that the Club's initiation oath is written in her style, and further notes the existence of a complete copy of the oath in Sayer's handwriting with strikeouts and other alterations suggestive of the work of drafting.  James Brabazon, Dorothy L. Sayers: a biography, ISBN 0-380-58990-7 (New York, 1982)

[vii] For complete versions of the Detection Club oath, see Brabazon pages 144 and 145, or Professor Mary Ann Gillies,  Gillies is an Associate Professor of English at Simon Fraser University.

[viii] Brabazon, p. 145.

[ix] Van Dine (a/k/a Wright) wrote the Philo Vance mysteries, including The Greene Murder Case, The Dragon Murder Case, The Garden Murder Case and others.

[x] Simon Fraser University is located in Burnaby, British Columbia, Canada.

[xi] Ngaio Marsh, Artists in Crime, ISBN 0-515-07534-5 (New York, 1938).

[xii] Ngaio Marsh, Death in a White Tie, ISBN 0-515-08591-X (New York, 1938).

[xiii] Sir Arthur Conan Doyle, The Complete Sherlock Holmes, ISBN 0-385-00689-6 (Garden City, New York, various copyright dates).  This entire example is taken from the first two chapters of A Study in Scarlet.

[xiv] This phrase does not appear in the first two chapters of A Study in Scarlet, and is used here only as an example.