Thank you to Ferdie for coming up with these.
Rule 1: All Locked Room cases must begin with a Statement of Mystery, explaining to the opponent exactly which questions they are required to answer.
Rule 2: Locked Room solutions must not involve the supernatural, nor may they require specialized technical knowledge.
Rule 3: "Filigree" - pointless ornamentation that exists solely to make a room more difficult - is forbidden. Any and all details that are required in the solution must be justified as actions that a person could reasonably perform. Thus, "I stabbed X, shot X, poisoned X, threw X off a bridge, then burned the corpse" is simply not admissible... unless there's a good in-character reason for each separate step included in the mystery.
Rule 4: If a Locked Room includes some step that would be very likely to lead to the capture of the murderer or the immediate solution of the room, discovery of this step will result in immediate victory. For example, "I ate the victim over several days" (in the absence of a scenario allowing a person to get away with such a thing) is a step that would result in immediate loss if discovered... if the Judge even allows it at all.
Rule 5: If a significant amount of time passes without progress, in the eyes of the Judge, both sides may request details that would be obtainable during a police investigation, such as an autopsy report listing BROAD (not specific) cause of death, and objects found at the scene. If you want to be safe from this, you must have a way of removing the evidence!
Rule 6: Good sporting conduct shall be maintained at all times, or else.
GOLDEN TRUTH: The Judge is the final arbiter of fairness, and must Judge in as unbiased a manner as possible. A Judge should not only follow the letter of the rules, but also seek to preserve elegance in the mysteries at hand.
