Rules of mystery writing

Bets are open, how many did Ryukishi manage to break?

• 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.
• All supernatural or preternatural agencies are ruled out as a matter of course.
  • This is a work of fiction, cackle cackle.
• Not more than one secret room or passage is allowable.
  • There has been exactly one so far, unless you count the whole of Kuwadorian.
• No hitherto undiscovered poisons may be used, nor any appliance which will need a long scientific explanation at the end.
  • We still don't trust Ryuukishi on this one.
• No Chinaman must figure in the story.
• No accident must ever help the detective, nor must he ever have an unaccountable intuition which proves to be right.
• The detective must not himself commit the crime.
  • Indeed, Battler is not Beatrice nor the culprit according to some red truths.
• The detective must not light on any clues which are not instantly produced for the inspection of the reader.
• 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.
  • It's hard to claim Battler is only slightly below the average, but you get a pass.
• Twin brothers, and doubles generally, must not appear unless we have been duly prepared for them.
  • Maybe he snuck in a twin again but it's not confirmed.