Dungeon

A **Dungeon** (ダンジョン, *Danjon*) is any type of adventuring location in MMO games, which is designed like a Dungeon or maze-like structure that has numerous paths, monsters, and rooms.

## Dungeons

In Aincrad, Dungeons are tower-like structures with many floors that connect each Aincrad Floor to the next. The only unifying feature among Dungeons is their 100 metre height, as each Dungeon has an individual scale and design. Some may be bulky and squat with uniform width, others are narrow and willowy.

Within each Aincrad Floor in Sword Art Online, one or more Field Bosses were strategically placed somewhere between the Teleport Gate and the entrance to each Dungeon in such a way that the Dungeon could not be accessed until this Boss was defeated.

The inside of a Dungeon is populated with numerous monsters, some of which respawned in approximately five minutes in Sword Art Online. Pale-blue lights are situated high above the Dungeon floor to provide a modicum of lighting.

The Boss Room of a Dungeon must be found on the topmost Dungeon level and cleared before the stairs to the next Aincrad Floor would be opened. In Sword Art Online, the walls of the staircase leading to the next Aincrad Floor contained thematic hints regarding the content of the following Floor. The most striking and memorable hint was a relief etched into the closed double-doors at the top of the stairs. Pushing these two stone door halves apart in the middle opens the door.

### Strategy

Dungeons in Sword Art Online are literally mazes, full of difficult winding paths, traps, hidden rooms, and dead ends. Because of the difficulty of the paths, it often takes Front Line players a week to "map" the Dungeon on average, before the Boss Room is found.

At that point, Front Line players typically hold a meeting to strategize the Boss Battle. Several expeditionary parties are sent to gather information on the Boss before a real raid is attempted.

Between the Closed Beta Test and the Official Release, the Dungeon maps were likely changed, since it took more than a month for the first floor Boss Room to be located.

### Dungeon Feature

#### Safe Areas

Most Dungeons have a handful of safe areas, where monsters do not enter and attack players. They can be recognized by a special colored torch placed in the four corners on the wall. Although it is possible to stay in safe areas for several days on end, it is described as a particularly discomforting and sleepless experience, since nearby monster footsteps or growls can be heard frequently.

#### Boss Rooms

A Boss Room is an enormous room, located at the topmost floor of a Dungeon in each Aincrad Floor. These rooms house doors to the stairs that lead to an upper Aincrad Floor, but these doors are protected by a powerful monster, called a Boss, which requires large raiding parties to take down, that resides within the Room. After a Boss is defeated, it will never re-spawn in the game.

The shape of the room differs from Floor to Floor. For example, the 1st Floor Boss Room was the shape of a rectangle, while the 74th Floor Boss Room was the shape of a dome. However, all Boss Rooms have several things in common. First of all, each one has only 2 entrances/exits: 1 from the Dungeon below and 1 on the other side of the room leading to the next Floor. Although these doors usually stay open in SAO, allowing players to retreat from the Boss Fight if necessary, as the Bosses never leave their designated room, however, starting with the 75th Floor, the door would be sealed as soon as the players enter the room, preventing any chance of retreating. The Boss Rooms in New Aincrad are always sealed within 1 minute of entry, which is the time it takes for all the flames in the room to light up and form a circle and is considered as time given to players to prepare for the battle. The waiting time can be cancelled by pressing a stone button on the wall next to the door.

The Dungeon-side entrance's appearance is usually a sign of the toughness of the Boss inside: the lairs of weaker Bosses usually have crude and rough entrances, while the lairs of powerful Bosses are usually grim and made out of smoothly polished materials. All Boss Rooms are also quite dark, with many torches or other light sources, which only light up when the Boss Fight begins and dim out as soon as the battle is over, spread out throughout the room. Boss rooms starting with the 74th Floor come with Anti-Crystal Fields, which prevent the use of any crystals, including teleportation crystals, within the Room.

## Sub-Dungeons

Another type of Dungeon is called a Sub-Dungeon in SAO or just Dungeon in other games. In Aincrad, these Dungeons are not important to the clearing of the game, so Clearers do not take the time to clear them, therefore, they are mainly cleared by middle level players.

### List of known Sub-Dungeons

#### Sword Art Online

* Sunshine Forest (20th Floor).
* Lost Forest (35th Floor).
* Hill of Memories (47th Floor).
* Western Mountain (55th Floor).
* Secret Dungeon (a hidden Dungeon under the Black Iron Palace).

## Anti-Crystal Zone

One of the most lethal, but rare, traps in Aincrad's Dungeons is the **Anti-Crystal Zone** (結晶無効化空間, *Kessho Mukou-ka Kūkan*) trap. As the name suggests, this kind of trap prohibits the use of crystals, disabling the players from teleporting and healing themselves with crystals in battle. While crystals cannot be used, other items such as healing potions can be used but those take longer to use.

As a result, players who enter Anti-Crystal Zone rooms are forced to defeat all enemies, face death, or somehow escape through unconventional means. Beginning with the 74th Floor, Boss Rooms also became Anti-Crystal Zones. It is unknown if the Anti-Crystal Zones were an intentional feature, or one of SAO's many glitches.

### Known Anti-Crystal Zones

* The nest of X'rphan the White Wyrm in the Western Mountain.
* Boss Rooms from 74th Floor and higher.