Trial Chambers

{
 "title": "Trial Chambers",
 "rows": [
 {
 "field": "Any (link to Overworld article, displayed as Overworld) biome except for the (link to deep dark article, displayed as deep dark)",
 "label": "(link to Biome article, displayed as Biomes)"
 },
 {
 "field": "-40 to -20",
 "label": "<span title=\"The Y-level(s) that generation begins at. The structure is not restricted to these Y-levels.\">Y-level</span>"
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 {
 "field": "(values exceeds 1000 characters...)",
 "label": "(link to Mob article, displayed as Mobs)"
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 {
 "field": "\n* See (link to #Structure article, displayed as <span style=\"white-space: nowrap;\">§ Structure</span>) \n* See (link to #Blocks article, displayed as <span style=\"white-space: nowrap;\">§ Blocks</span>)",
 "label": "Consists of"
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 "invimages": [],
 "images": [
 "Trial Chambers isometric view.png"
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Trial chambers^{[note 1]} are uncommon underground structures that serve as a mid-game combat challenge.^[1] They consist mostly of copper blocks and tuff bricks, and are the only place where trial spawners and vaults naturally generate. Trial chambers are also the only place where breezes spawn, whose breeze rods can be used to craft wind charges. Various materials such as heavy cores and certain armor trims are obtained exclusively by unlocking vaults in trial chambers. As it is the only source of breeze rods and heavy cores, the structure is also the location where maces are obtained.

Trial chambers can also be used to obtain copper bulbs without entering the Nether or finding a nether fortress, and large quantities of copper blocks and it's derivatives.

Ominous trials can also take place here through Bad Omen, where Trial Omen causes all trial spawners to become ominous, making them more difficult and providing greater rewards.

Trial chambers generate underground in the Overworld. The starting room generates at an altitude of between Y=-40 and -20, but the structure is not restricted to those Y levels; the majority of the structure's rooms tend to generate between Y=-20 and 0.^[verify]

Trial chambers can only generate in new chunks, specifically ones that did not exist prior to Java Edition 1.21 and Bedrock Edition 1.21.0.

The generation of trial chambers follows a grid of 34×34 chunk regions centered on the world origin (X=0, Z=0). There is always one trial chambers structure generated in each region at a random location, unless a deep dark biome cancels the generation of the trial chambers.

While the origin point of the structure (corridor_end) cannot generate within a deep dark biome, other parts of it can intersect a deep dark biome.

Trial chambers can be located using trial explorer maps, which are sold by journeyman-level cartographer villagers for 12 emeralds and a compass. The maps always point to the nearest trial chamber relative to the cartographer that does not already have a trial explorer map that points to it. All maps bought from the same cartographer always points to the same structure.

In Java Edition, a given villager always trades the same map, which is determined upon the trade unlocking.

An online seed map such as mcseedmap.net or chunkbase.com may be used instead.

The starting room of the structure is corridor/end. This room connects to a chamber and a section of a corridor. At the end of the section of a corridor, an intersection links to another chamber and another section of a corridor is generated, but this time it ends on the atrium, which then leads to the entrance room.

The structure then branches out from some corridor/straight pieces.

All trial chambers structures found below are located in the folder client.jar/data/minecraft/structure/trial_chambers‌^{[JE only]} or data/behavior_packs/vanilla/structures/trial_chambers‌^{[BE only]}.

Trial chambers feature two corridors:

• a corridor going from the entrance room to the intersection, passing through four slices and the atrium;
• a corridor going from the intersection to the end room, passing through four slices.

The intersection connects both corridors, forming an L-shape. The intersection and the end room always lead to a chamber, while slices have a probability to lead to a hallway (see § Hallways).

The entrance generates at the end of one of the two corridors.

entrance_1 and entrance_2 include a vault, two entrance chests, and a platform containing either an oak, a mangrove, or a cactus; additionally, entrance_1 has a secret room containing a bed and a chest.

entrance_3 includes two vaults and three entrance chests.

The atrium generates between the entrance and the slices. It always contains an ominous vault above the doorway leading to the entrance and a fountain.

Murals are generated on both sides; they can depict either a bogged, a breeze, a spider, or a spiral shape. The grand staircase is also chosen randomly.

Corridor slices, or straight pieces,^{[note 7]} are sub-structures that make up the corridors; they are generated on top of a tuff brick plate. Each of the two corridors has four slices.

Except for straight_1 and straight_8, all slices have a copper door:

• straight_2 and straight_5 generate a copper door on the lower level;
• straight_3 and straight_6 generate a copper door on the middle level;
• straight_4 and straight_7 generate a copper door on the upper level.

On average, each trial chamber has 6.29 (⁴⁴⁄₇) doors. These copper doors can either lead directly to a chamber, a hallway or nothing.^[2] Provided the latter case doesn't happen:

• lower level doors always lead to a descending spiral staircase (lower_hallway_connector);
• upper level doors always lead to an ascending spiral staircase (upper_hallway_connector);
• middle level doors and these spiral staircases have a 97.48% chance to directly lead to a chamber, 2.44% chance to lead to a hallway piece, and 0.08% chance to directly lead to a dead-end (see § Hallways).

Both straight_6 and straight_8 generate with a trial spawner that can either spawn a melee, small melee or ranged mob (see § Mobs), but never breezes. straight_7 generates with a hidden vault.

In addition to their addons, slices can generate with various decorations such as flower pots, decorated pots, candles and corridor barrels (see § Decor). Some addons can generate with a trial spawner (that can either spawn a melee, small melee or ranged mob) and a vault.

The end room generates at the end of one of the two corridors. It always leads to one of these chambers with equal probability:

• chamber_1
• eruption
• assembly
• slanted

End rooms cannot lead to any other chamber, i.e. it excludes:

• chamber_2
• pedestal
• chamber_4
• chamber_8

End rooms always include an ominous vault. In addition to its ominous vault, end_2 also features a regular vault and an intersection chest.

The intersection is the room that connects both corridors. It always features a safer zone equipped with beds as well as an entrance to a chamber. In addition to that:

• intersection_1 and intersection_2 feature an ominous vault;
• intersection_2 and intersection_3 feature an intersection barrel;
• intersection_2 features a secret room with an additional bed and a decorated pot always containing 3 strings.^[3]

Hallways are segments that connect corridors to chambers. When a copper door generates in a corridor, it (or, in the case of an upper or lower door, the spiral staircase that follows it; see § Slices) may lead to one of the following pieces:

• a chamber (97.48%);
• a hallway segment (1.14%);
• an encounter (0.41%);‌^{[Java Edition only]}
• a dead end (0.08%).

If the selected piece cannot be generated, the game attempts to generate a different piece. After a certain number of failed attempts, it defaults to generating a dead end.​^{[more information needed]} If the dead end itself cannot be generated, no piece is generated.^[2]

This process is then repeated at the end of each hallway segment or encounter. Furthermore, hallways never branch, meaning that every copper door found in corridors eventually leads to a single chamber, a dead end, or nothing.

Encounters are hallway pieces that consist in "short challenges leading to a larger chamber".^[5] They feature a single trial spawner and a vault.

Chambers are large combat rooms that contain multiple trial spawners and vaults, as well as one ominous vault. Chambers can be accessed from hallways, intersections, end rooms, and corridor slices.

Each chamber design has several potential entrances, of which only one is connected to the rest of the structure. The remaining entrances are sealed with an entrance cap (see § Hallways). Each potential entrance, including the sealed ones, generates a disposal consisting of a hopper placed above a barrel (see § Decor), allowing players to manage their inventory before entering a chamber.^[6]

Chamber_1 and Chamber_2