Locked Room

A **Locked Room** (密室(みっしつ), *Misshitsu, "Sealed Room"*) is one of the core terms of mystery fiction, particularly those in deduction focused subgenres (whodunit and honkaku stories). The term has both a literal and figurative meaning. Literally speaking, a locked or sealed room refers to any location in which entry and exit is rendered physically impossible. In addition to the physical meaning, similar situations can also become a figuratively "locked" room due to having seemingly impossible circumstances with more abstract causes. In other words, an impossible crime without a physically locked room may be called a figurative or psychological locked-room.

## Definition

A locked-room is a core piece of mystery jargon. It refers to any mystery which appears obviously impossible on the surface, but must still have happened due to the presence of an incident or crime in opposition to that impossibility. Most commonly, this is the same as saying whenever a corpse is found in a room that is sealed such that the culprit could not have entered or exited the room. Other terms for the concept include a "sealed-room", a "hermetically sealed chamber", or simply an "impossible crime".

Two separate kinds of locked rooms exist. A physical, or literal, locked room refers to a situation where physical entry or exit is blocked, usually due the doors and windows of a crime scene being locked from the inside. A psychological, or figurative, locked room refers to a situation where entry or exit to the crime is treated as impossible due to non-physical limits; psychological locked rooms often involve alibi tricks, clearly visible crime scenes that would have left any murderer implausibly exposed, implausible causes of death, or other means of making the crime appear "impossible".

The prevalence of mysteries revolving around locked room situations has led to it sometimes being considered its own sub-subgenre of whodunits. Many mystery magazines and distributors separately label "locked room" or "impossible crime" mysteries as their own category.

## Types of locked-rooms

As a result of the extensive contribution of many authors of the genre, locked room mysteries are broadly "solved", in the sense of almost all conceivable tricks fitting into established categories. The individual tricks themselves may be original, but even these unique tricks almost always fit into more conventionally familiar categories. These are:

* Accidental deaths that are not truly locked room murders.
* The use of some weapon to induce an accident, such as hallucinogenic poison or gas.
* A trap placed within the room in order to commit a remote murder.
* Suicide that is made to look like a murder.
* Altering the apparent time of death in order to create a psychological locked-room.
* Remote murder by means of an elaborate contraption, usually one that leaves no traces, i.e. an icicle murder or murder by string.
* There is a hidden passage or room that allows the culprit to avoid using the locked door or window.
* Simple tricks to lock the door or window from the outside such that it appears to be locked from the inside.
* Removing the door or window and replacing it entirely in order to create an effect as above.
* Locking the door from the outside, and then planting the key within the locked-room after the corpse is discovered.
* There was no true locked-room, it was actually created by the culprit after the discovery the corpse.
* The corpse is actually still alive, and the locked-room is an illusion in its entirety.