Brain Burst creates a stage as a "skin" on video data pulled from the Social Camera Network, essentially generating a three-dimensional version of the Burst Linker's location with certain additional effects applied. Each stage has its own unique set of characteristics. For example, the Twilight Stage is always set at low light, right before sundown, and its buildings are easy to destroy.
One particularly important characteristic of a stage is whether entrance into buildings is permitted. For example, entrance is allowed in the Era's End stage, but not in the Twilight stage. If the Burst Linker is indoors while accelerating into an "outdoor" stage, their duel avatar will spawn on the roof.
Some stages may contain polished train tracks where railways are, indicating that the stage contains running trains. However, such trains occur so infrequently that they may not appear even once in a normal duel.
Each stage belongs to one of eight attributes: Fire, Wind, Water, Earth, Wood, Metal, Dark, or Holy. The first six are referred to as nature stages. The attribute of a stage affects not only Burst Linkers, but also the Enemies that live within. For example, the Archangel Metatron is weaker in Dark-attribute Stages, making it almost a necessity to challenge her within such a stage.
Stages of the same attribute differ in "strength" as well. This equates roughly to how "pure" the stage is — for example, the Hell Stage is the most "powerful" Dark-attribute stage, while the Purgatory Stage is much weaker.
An Object is a specific element of a stage, such as a building, a terrain object, or a non-player creature. Objects are found in many stages and can sometimes have a great effect on a duel's outcome. Destroying Objects will fill a Duel Avatar's Special Gauge; as such, many Burst Linkers will use such tactics to gain an advantage over their opponent.
The ground, as well as buildings found in stages that prohibit entrance, are not objects, and are thus immune to attacks. However, when attacked with another physically immune object, e.g. Wolfram Cerberus with Physical Immunity active, both are damaged.
A Transition refers to the overwriting and refreshing of the Unlimited Neutral Field by replacing the current stage with a new one. They happen at irregular intervals; the exact timing is thought to be random.
However, the sequence of stages follows some general rules. First, the amount of time a Stage will be active can be anywhere from 3 to 10 days in the Unlimited Neutral Field, but no longer than that. Stages of each attribute appear with almost equal frequency. In addition, the stage selected afterwards usually has a different attribute, so a Fire stage usually will not transition to another Fire stage. Further, if the game rotates between the six nature stages for a long period of time, then a "powerful" Dark or Holy stage will appear afterwards. A non-nature stage will almost always transition into a nature stage.
There are also other rules whose specifics have not been discussed, but they are known well enough that Iron Pound was able to predict when a high-level Dark stage was most likely to appear.
List of Known Stages
There are no in-game names for the stages — stage names are given by the players. As such, some players may refer to certain stages by different names.
- Wasteland – This stage is one of the most peaceful of the earth stages, lacking natural traps or moving objects. Dry winds blow throughout the stage, and cirrus clouds cover the sky, rarely allowing red sunbeams to shine through. Regions with many plants in real life will have them replaced with cacti. Structures are replaced by reddish-brown rock formations, which may contain labyrinthine cracks large enough for a duel avatar to enter. As real-life structures have been converted to rock, buildings cannot be entered.
- Ocean – Laser attacks become unusable.
- Ice – This stage is a snowy plain. A layer of snow around 20 centimeters deep covers the white ground underneath, lowering damage from hitting the ground. Its buildings and structures are converted into giant, hard ice constructs, while large icicles occasionally fall from these strucutres. As real-life structures have been converted to ice blocks, buildings cannot be entered. Its in-game designation is W04, likely standing for the 4th purest water stage.
- Water – This stage has a layer of water on the ground around 10 centimeters deep, with small waves on it due to the wind. Structures in the stage are turned into concrete frames. The weather is variable — the stage either has bright sunlight in a cloudless sky, or dark clouds with lightning flashing between them. Some Burst Linkers consider it a pretty version of the Era's End stage.
- Storm – In this stage, there are dark clouds moving rapidly across the sky with constant rain. The amount of rain changes randomly, however, and there will be occasional strong gusts of wind. Rarely, the winds may be strong enough to destroy the environment, up to causing tall narrow skyscrapers to collapse. Negative corrections will also be applied to laser attacks.
- Drizzle – Negative corrections will be applied to laser attacks.
- Sewer – Above ground, this stage is constructed of gray asphalt and concrete like in the real world. The only differences are the numerous manhole covers set in the ground, and the tall, sturdy concrete walls to force combatants into the manholes. As extra incentive, items above the ground provide minimal SP. The manholes lead to large concrete sewer tunnels underground, in the form of semicircular cylinders around 6 or 7 meters wide. At the center of the stage is a near-hemispherical arena 50 meters wide and 30 meters high. The floor itself is covered in murky gray water reaching up to the ankles. Where the water does not reach, surfaces are covered in mold, moss, and some unknown sticky liquid, with rusted metal pipes of various sizes running along the walls. The only lighting in the stage is provided by dim fluorescent tubes on the ceiling, leaving dark spots where small living creatures scurry around. Oil drums can be found in the sewers that release a glowing gas when broken, which fills up almost half of the Special Attack Gauge. It is, for some reason, the least popular Water stage. Judging by the design philosophy of the stage, buildings likely cannot be entered.
There are 5 Fire stages in total.
- Crimson – The highest-tier Fire stage.
- Volcano – The second-highest Fire stage.
- Lava – A mid-tier Fire stage.
- Scorched Earth – The second-lowest Fire stage.
- Desert – The lowest-tier Fire stage. Its land is covered in sand dunes and buildings have been converted to rocky structures. The uniformity of the stage makes it hard to navigate. As real-life structures have been converted to rock, buildings likely cannot be entered.
- Thunder – Its structures are made of metal pipes, and there is lightning flashing in the clouds. If anyone rises higher than 100 meters above ground level, they would be struck by lightning. For example, Silver Crow was forced to fly near ground level. This could be exploited by throwing easily destructible conductive objects into the air.
- Sandstorm – A mid-tier Wind stage. This stage has occasional strong sandstorms that cause huge damage to HP and armor, and can even kill a duel avatar outright. While its sky is normally a pale blue, a gray color on the horizon means that a sandstorm will arrive in around 30 seconds. While its structures become mountains, they can be entered due to the caves within, which have been noted as resembling the fairy chimneys in Cappadocia.
- Primeval Forest – This stage contains tall trees. Its air is humid. It contains many large animals which will attack players, such as giant beetles, giant snails, and tyrannosaurs. It is also rumored that real-life animals may be converted to an appropriate animal in-game.
- Corroded Forest
- Buffer – This stage is constructed of a soft, bouncy, cushion-like material of various light or flat colors such as cream, beige, light green, or light brown. Building walls and the ground are made of diagonal squares with sides of 80 centimeters. Objects are rounded. The environment is extremely hard to destroy, being impervious to bullets, blades, and even drills. Damage from impacts is minimized.
- Steel – The stage is constructed of rebar and flat steel panels, which makes structures hard to destroy. Electric and magnetic effects are strengthened, and the sounds of footsteps will be amplified. Its ground is tiled with diamond metal tiles. Trees are converted to rusted skeletal structures. Its sky, however, remains blue, with wisps of clouds.
- Demon City – This stage is covered with dark blue metallic structures that are extremely hard to damage. From these buildings, searchlights shine up to illuminate the clouds that cover the entire sky. The buildings themselves have their walls covered in blade-like decorations. In regular duels or territory battles, it will be nighttime. The ground is covered in geometric tiles that fit together tightly.
- Hell – The purest of the Dark stages. It has purple clouds, and all terrain outdoors cause damage through one of various means. Its ground can be a poisonous bog, an acidic swamp, a lava lake, covered in steel spikes, or more. Its in-game designation is UH01, which may stand for the most Unholy stage.
- Deadly Sin – One of the purest Dark stages, and the counterpart to Sacred Ground. The world looks murky red, and its sky is also a garish red. Its ground and structures are covered in gray tiles, with blood leaking out from between their seams, creating pools of blood everywhere. The stage has many special effects, but the trickiest is that half of the damage from direct physical attacks such as punches and kicks will be reflected back at the attacker.
- Purgatory – This stage is quite dim, making slight differences in colors hard to spot. Twisted organic structures and occasionally, cultish shrines replace the buildings of the real world. The ground is metallic.
- Bizarre Festival – As a mid-level Dark stage, many mechanisms are present to obstruct movement. The stage's sky is dark and cloudy, as if it is about to rain, but everything close to the ground is covered in a warm light emitted by buzzing and flickering incandescent light bulbs, which hang from wires two storeys above the ground. Stick-like, meter-tall humanoid shadows can be seen moving or dancing in groups, or selling strange items broken stalls that line the walls. They can respond to the surrounding situation. Celebratory music plays in the background, made eerie by occasional off-key notes. Buildings cannot be entered.
- Plague – A mid-level Dark stage, this stage's main feature is differently-colored poisonous mists that are emitted from the ground, each carrying a different detrimental effect. As the stage's name suggests, these mists infect a duel avatar, which can then transmit the effect to those they come into contact with. It has a gray, wet ground, a yellow-green sky, skeletal trees, and rotted buildings covered in rust. Known mist effects include disabling the special move gauge, applying visual impediments, causing a loss of balance, and others. The known types of mist are:
- Pink – Does damage over time
- Light blue – Impairs hearing, causing muffled sounds
- Cemetery – A low-level Dark stage. This stage is dotted with headstones across its landscape. Its ground is made of black mud, and the it is always nighttime, with a crescent moon. Grasping hands will grow out of the ground to obstruct movement, and even restrain duel avatars. Occassional howls will be heard throughout the stage. Bats will also occassionally fly through the sky.
- Heaven – The purest Holy stage.
- Sacred Ground – A high-purity Holy stage, the counterpart of the Deadly Sin stage. Its sky is a pearl-like milky white, and its structures are a pure white as well. Its ground is covered in white tiles with Arabic patterns that prevent slipping. Transparent floating octahedral energy crystals are situated above roads and open spaces, and turn the light shining down into a rainbow pattern around them. When broken, the crystals will ring and fill up a duel avatar's Special Attack Gauge. In the Unlimited Neutral Field, they may also drop Enhanced Armaments. The crystals also tempt Burst Linkers to break them regardless of whether their SP is full. Kuroyukihime suspects Okinawan Burst Linkers call it Nirai Kanai.
- Moonlight[note 1] – The structures of this stage are made of a chalky substance, and are in a Gothic style. A bright full moon shines above the stage, casting long shadows. The floor is covered in a layer of fine white sand. Objects are less durable than average. If the Unlimited Neutral Field transitions to this stage, Enemies will appear less often. Its in-game designation is HL05. This likely stands for the 5th Holy stage.
- Twilight – A low-level Holy stage. Structures are made of cracked, dull marble. It is also quite dim, as if it is twilight. It has occasional gusts of wind, and is arid. Its internal designation is Field Attribute HL06, which may mean it is the 6th most Holy stage.
- Space – Suspected to belong to none of the elements, the Space stage consists of several floating islands and the Sun in a void dotted with stars and nebulas of different colors. The islands as they first form have Earth-like gravity, but as they are broken over the course of the battle, the strength of gravity decreases according to their size. Apart from the islands, there is no gravity anywhere else, and a small jump could send a duel avatar flying off until they hit the edge of the combat area, if one exists. There is no air in the stage, but voices can still be transmitted. The structures on its islands are fragile, but are still sturdier than the ones in Twilight.
- Ancient Castle – Also known as Okinawan Fortress. Its structures are quite hard.
- Era's End – This stage looks like a post-apocalyptic urban area. Buildings cannot be entered.
- Downtown – This stage is full of buildings with neon lights, and looks similar to Akihabara Electric Town. It has uneven terrain and very few open spaces, making it inconvenient to train or carry out activities with many people. Buildings cannot be entered.
- Factory – This stage has huge gears, conveyor belts, and weird machines, taking on a steampunk look. Only avatars with high defence will remain unhurt when breaking items in this stage.
- Fairy World
- Salt Lake – This is a rare stage whose primary feature is the layer of highly reflective, saturated brine on the ground, causing metal avatars' armor to corrode easily. The terrain is flattened so the brine does not cause parts of the stage to be flooded while others remain dry. Covering everything, from the ground to various structures, is a layer of salt. It seems to permanently be at noontime, with glaring sunlight. Buildings have been replaced with whitish salt mountains with no interiors, so they cannot be entered.
- Shopping Mall
- Weathered – This is yet another post-apocalyptic stage. Structures are transformed into ruins with crumbling concrete and rusted rebar. The road has small cracks. The wind causes dust to be blown everywhere. The sky is a clear blue. This stage has functioning train tracks, and its trains are covered in rusted steel plates.
- As the in-game designation of Moonlight is HL05, and another HL stage (Twilight) has been identified as Holy, this means Moonlight is likely Holy as well.
- Accel World Volume 11 Chapter 4
- Accel World Volume 17 side story: Two Black Swords, Two Silver Wings Chapter 4
- Accel World Volume 09 Chapter 2
- Accel World Volume 11 Chapter 14
- Accel World Volume 13 Chapter 8
- Accel World Volume 14 Chapter 3
- Roar of the Sea at the Ends of the Earth Chapter 7
- Accel World Volume 12 Chapter 7
- Accel World Volume 20 Chapter 3
- Accel World Volume 16 Chapter 8
- Accel World Volume 12 Chapter 9
- Accel World Volume 17 Chapter 1
- Accel World Volume 16 Chapter 5
- Accel World Volume 13 Chapter 5
- Accel World Volume 24 Chapter 2
- Magisa Garden #032: Water Gun Balloon Game
- Accel World Volume 19 Chapter 2
- Accel World Volume 11 Chapter 6
- Accel World Volume 24 Chapter 3
- Accel World Volume 12 Chapter 2
- Accel World Volume 12 Chapter 6
- Accel World Volume 13 Chapter 4
- Accel World Volume 17 Chapter 4
- Accel World Volume 11 Chapter 10
- Accel World Volume 20 Chapter 5
- Accel World Volume 21 Chapter 5
- Accel World Volume 16 Chapter 3
- Accel World Volume 12 Chapter 3
- Accel World Volume 11 Chapter 9
- Accel World Volume 20 Chapter 2
- Accel World Volume 17 Chapter 2
- Accel World Volume 12 Chapter 4
- Accel World Volume 18 Chapter 9
- Accel World Volume 19 Chapter 1
- Accel World Volume 11 Chapter 12
- Accel World Volume 14 Chapter 6
- Accel World Volume 15 Chapter 1
- Accel World Volume 18 Chapter 3
- Magisa Garden #008: Wheel and Deal
- Accel World Volume 03 Chapter 2
- Accel World Volume 24 Chapter 7