Trial Chambers Wiki Guide

Trial chambers are underground structures which serve as a mid-game combat challenge.

Generation

Trial chambers generate underground in the Overworld. The starting room generates at a height between -20 and -40.

In Java Edition, the generation of trial chambers follows a grid-like formation. There is always one trial chamber generating in each region of 32×32 chunks, with the world origin (X=0, Z=0) being at the intersection of four regions. The trial chamber generates at a random location within the region it locates in.

In Bedrock Edition, trial chambers generate much less frequently, and do not generate in a grid pattern.

Structure

The trial chambers are procedurally generated structures made mainly of tuff bricks, copper, and their variants. The chambers consist of a number of different rooms, some of which contain trial spawners. Some trial spawners may contain the breeze, a playful hostile mob.

The structure is arranged from 4 main components: hallways, corridors, intersections, and chambers.

File structure

All trial chambers structures found below are located in the folder client.jar/data/minecraft/structures/trial_chambers

Trial Spawners

Blocks on the floor near a trial spawner indicate which type of mob is summoned when that spawner is activated.

When a trial chamber generates, one mob from each category is selected. All mobs within the same category have the same chance to be selected. The breeze is in its own group, only generating in special rooms which have a chance of generating in any trial chamber.

Breeze

Mob spawned	Block surrounding spawner
	Chiseled Tuff

Melee

Mob spawned	Block surrounding spawner
	Mossy Cobblestone
	Chiseled Sandstone
	Moss Block

Small Melee

Mob spawned	Block surrounding spawner
	Stone Bricks
	Cobblestone & Mossy Cobblestone
	Stone with Cobweb on top.
	Stone with Cobweb on top & Podzol with a Red Mushroom

Ranged

Mob spawned	Block surrounding spawner
	Packed Ice
	Bone Block
 with Arrow of Poison	Bone Block & Podzol with a Red Mushroom

Natural hostile mob spawning is disabled within a trial chamber; mobs are only able to spawn from the trial spawners.

Naturally generating trial spawners in trial chambers use different values for the length of time between spawn attempts, how many mobs are spawned in total, how many mobs can be alive at a time, and how these values change with additional players. All naturally generated spawners attempt to spawn mobs every 20 ticks (1 second), or every 160 ticks (8 seconds) for the slow versions of the spawners. Additionally, naturally generated breeze spawners allow 1 breeze to exist at once (+0.5 every additional player present) and will stop after spawning 2 mobs (+1 for every additional player present). All other spawners generated in trial chambers use the default value of 2 total mobs, but add 2 for every additional player present, allow 3 mobs at once, and add 2 mobs for every additional player present. This is represented in the table below.

Components

All trial chambers follow a common structure, containing an entrance chamber leading to a corridor. This corridor is followed by an intersection leading to another corridor on one side and a combat chamber on the other. The second corridor leads to a corridor end chamber which connects to another combat chamber. More combat chambers may generate from the sides of the corridors. Due to a maximum size imposed on the structure, long corridors may cause an incomplete generation of the structure on rare occasions.

Entrance

The entrance chamber corridor/entrance_1 generates in every trial chamber and contains a tree next to two chests with entrance loot, a vault up on a ledge, and a hidden room containing a bed and a reward chest.

Corridors

Both corridors are three stories tall and may contain trial spawners of any category as well as supply chests and tripwire traps. The length of the corridor can vary in multiples of four segments. Each segment may contain a side door from any of the floors connecting to a combat chamber through hallways.

There are two types of corridor ends connecting the second corridor to a combat chamber:

• corridor/end_1 contains multiple stairs converging from all corridor entrances to the chamber exit.
• corridor/end_2 contains water filling the bottom layer and a chest behind the stairs containing intersection loot.

Hallways

Some hallways end at a dead end, which is hallway/rubble. This dead end has a reward chest at the end.

Intersections

There are two types of intersections, both connecting two corridors with a combat chamber and containing a room with four beds and a barrel with loot:

• intersection/intersection_1 connects the corridors through the bottom floor and has a staircase up to the bedroom.
• intersection/intersection_2 connects the corridors through the top floor and has an underwater bedroom accessible via a ladder.

There are a variety of combat chambers, each containing multiple trial spawners. Most chambers have several dispensers along the walls triggered by oak buttons.

Chambers

• chamber/chamber_1 is a tall room with a central pillar that can be reached by crossing copper grate platforms hanging on chains or narrow copper block bridges. A gap in the pillar has a breeze trial spawner, and one or more corners may have an upper ledge with a ranged trial spawner and possibly a vault. Some copper grate obstacles may be placed at random on the bottom level.
• chamber/chamber_2 is similar to the above room, but with the floor covered in powder snow and some obstacles made of tuff bricks. The breeze trial spawner is replaced with a ranged trial spawner, and the only dispenser is found beneath the corner ledge (if present), but with no buttons or contents.
• chamber/chamber_3 is a large room with wide bridges, a spiral staircase in one corner, three trial spawners (2 melee and 1 ranged), and up to three vaults, but no dispensers. One of the bridges may have copper grates underneath, leaving a 1-block high gap. The vault near the bottom of the spiral staircase may be replaced with a small melee trial spawner.
• chamber/chamber_4 is a small room with wide bridges, three small melee trial spawners, and two vaults, but no dispensers. Copper grates under one of the bridges leave a 1-block high gap that the small mobs can easily pass through.
• chamber/chamber_5 is a large round room with magma blocks around a central platform, three trial spawners (1 melee, 1 ranged, and 1 breeze), and two vaults. Atop the platform is a fountain-like structure with an upward-facing dispenser containing a water bucket.
• chamber/chamber_6 is a large square room with a platform along one wall, which has a vault and two trial spawners (1 ranged and 1 breeze). The center of the chamber is filled with random structures and may include another vault, another ranged trial spawner, additional dispensers, and other obstacles.
• chamber/chamber_8 is a tall, narrow room with five ranged trial spawners on three successively higher ledges. Under each ledge is a row of oxidized copper trapdoors. There are two vaults at the bottom and two more vaults on the highest ledge.
• chamber/chamber_9 is a wide room with the floor gradually increasing in height. Atop some platforms are three trial spawners (2 ranged and 1 breeze), and there are two vaults.

Loot

Loot is available from vaults, chests, barrels, dispensers and decorated pots from within the chambers. Players who defeat a trial spawner each receive rewards; this loot scales depending on the amount of people who defeat the trial spawner.

Vaults

In Java Edition and Bedrock Edition, each trial chambers reward container contains 2–6 item stacks, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per container	Avg.containers to loot
Enchanted Book[F]	1	12⁄110	36.2%	0.436	2.8
Emerald	2–6	8⁄110	25.6%	1.164	3.9
Iron Horse Armor	1	8⁄110	25.6%	0.291	3.9
Damaged Shield	1	6⁄110	19.8%	0.218	5.0
Saddle	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Axe	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Pickaxe	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Shovel	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Helmet	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Chestplate	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Leggings	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Boots	1	6⁄110	19.8%	0.218	5.0
Golden Horse Armor	1	6⁄110	19.8%	0.218	5.0
Enchanted Book[I]	1	5⁄110	16.8%	0.182	6.0
Enchanted Crossbow	1	3⁄110	10.4%	0.109	9.6
Enchanted Golden Apple	1	3⁄110	10.4%	0.109	9.6
Diamond Horse Armor	1	3⁄110	10.4%	0.109	9.6
Enchanted Diamond Axe	1	3⁄110	10.4%	0.109	9.6
Enchanted Diamond Chestplate	1	3⁄110	10.4%	0.109	9.6
Diamond	1–3	2⁄110	7.0%	0.145	14.2

Chests

In Java Edition and Bedrock Edition, each trial chambers entrance chest contains 2–3 item stacks, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per chest	Avg.chests to search
Arrow	5–10	10⁄36	55.1%	5.208	1.8
Honeycomb	2–8	10⁄36	55.1%	3.472	1.8
Wooden Axe	1	10⁄36	55.1%	0.694	1.8
Stick	2–5	5⁄36	31.0%	1.215	3.2
Trial Key	1	1⁄36	6.8%	0.069	14.7

In Java Edition, each trial chambers corridor chest contains 1–3 item stacks, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per chest	Avg.chests to search
Tuff	8–20	3⁄19	28.4%	4.421	3.5
Scaffolding	2–10	2⁄19	19.6%	1.263	5.1
Bamboo Planks	3–6	2⁄19	19.6%	0.947	5.1
Torch	3–6	2⁄19	19.6%	0.947	5.1
Bamboo Hanging Sign	1–4	2⁄19	19.6%	0.526	5.1
Ender Pearl	1–2	2⁄19	19.6%	0.316	5.1
Damaged Stone Axe	1	2⁄19	19.6%	0.211	5.1
Damaged Stone Pickaxe	1	2⁄19	19.6%	0.211	5.1
Honeycomb	2–8	1⁄19	10.2%	0.526	9.8
Damaged Iron Axe	1	1⁄19	10.2%	0.105	9.8

In Bedrock Edition, each trial chambers corridor chest contains 1–3 item stacks, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per chest	Avg.chests to search
Tuff	8–20	3⁄19	28.4%	4.421	3.5
Scaffolding	2–10	2⁄19	19.6%	1.263	5.1
Bamboo Planks	3–6	2⁄19	19.6%	0.947	5.1
Torch	3–6	2⁄19	19.6%	0.947	5.1
Bamboo Hanging Sign	1–4	2⁄19	19.6%	0.526	5.1
Ender Pearl	1–2	2⁄19	19.6%	0.316	5.1
Damaged Stone Axe	1	2⁄19	19.6%	0.211	5.1
Damaged Stone Pickaxe	1	2⁄19	19.6%	0.211	5.1
Honeycomb	2–8	1⁄19	10.2%	0.526	9.8
Enchanted Iron Axe	1	1⁄19	10.2%	0.105	9.8

In Java Edition and Bedrock Edition, each trial chambers intersection chest contains 1–3 item stacks, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per chest	Avg.chests to search
Amethyst Shard	8–20	20⁄86	39.7%	6.512	2.5
Cake	1–4	20⁄86	39.7%	1.163	2.5
Block of Iron	1–2	20⁄86	39.7%	0.698	2.5
Diamond	1–2	10⁄86	21.5%	0.349	4.6
Block of Emerald	1–3	5⁄86	11.2%	0.233	8.9
Damaged Diamond Axe	1	5⁄86	11.2%	0.116	8.9
Damaged Diamond Pickaxe	1	5⁄86	11.2%	0.116	8.9
Block of Diamond	1	1⁄86	2.3%	0.023	43.3

In Java Edition and Bedrock Edition, each trial chambers reward container contains 2–6 item stacks, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per container	Avg.containers to loot
Enchanted Book[F]	1	12⁄110	36.2%	0.436	2.8
Emerald	2–6	8⁄110	25.6%	1.164	3.9
Iron Horse Armor	1	8⁄110	25.6%	0.291	3.9
Damaged Shield	1	6⁄110	19.8%	0.218	5.0
Saddle	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Axe	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Pickaxe	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Shovel	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Helmet	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Chestplate	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Leggings	1	6⁄110	19.8%	0.218	5.0
Enchanted Iron Boots	1	6⁄110	19.8%	0.218	5.0
Golden Horse Armor	1	6⁄110	19.8%	0.218	5.0
Enchanted Book[I]	1	5⁄110	16.8%	0.182	6.0
Enchanted Crossbow	1	3⁄110	10.4%	0.109	9.6
Enchanted Golden Apple	1	3⁄110	10.4%	0.109	9.6
Diamond Horse Armor	1	3⁄110	10.4%	0.109	9.6
Enchanted Diamond Axe	1	3⁄110	10.4%	0.109	9.6
Enchanted Diamond Chestplate	1	3⁄110	10.4%	0.109	9.6
Diamond	1–3	2⁄110	7.0%	0.145	14.2

In Java Edition and Bedrock Edition, each trial chambers supply chest contains 3–5 item stacks, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per chest	Avg.chests to search
Arrow	4–14	2⁄18	37.3%	4.000	2.7
Glow Berries	2–10	2⁄18	37.3%	2.667	2.7
Baked Potato	2–4	2⁄18	37.3%	1.333	2.7
Damaged Stone Pickaxe	1	2⁄18	37.3%	0.444	2.7
Tuff	5–10	1⁄18	20.4%	1.667	4.9
Poison Tipped Arrow	4–8	1⁄18	20.4%	1.333	4.9
Slowness Tipped Arrow	4–8	1⁄18	20.4%	1.333	4.9
Acacia Planks	3–6	1⁄18	20.4%	1.000	4.9
Torch	3–6	1⁄18	20.4%	1.000	4.9
Bone Meal	2–5	1⁄18	20.4%	0.778	4.9
Moss Block	2–5	1⁄18	20.4%	0.778	4.9
Potion of Regeneration	2	1⁄18	20.4%	0.444	4.9
Potion of Strength	2	1⁄18	20.4%	0.444	4.9
Milk Bucket	1	1⁄18	20.4%	0.222	4.9

Barrels

In Java Edition and Bedrock Edition, each trial chambers intersection barrel contains 1–3 item stacks, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per barrels	Avg.barrels to loot
Bamboo Planks	5–15	10⁄33	49.3%	6.061	2.0
Baked Potato	6–10	10⁄33	49.3%	4.848	2.0
Damaged Enchanted Golden Axe	1	4⁄33	22.3%	0.242	4.5
Damaged Enchanted Golden Pickaxe	1	4⁄33	22.3%	0.242	4.5
Diamond	1–3	1⁄33	5.9%	0.121	16.8
Bucket	1–2	1⁄33	5.9%	0.091	16.8
Compass	1	1⁄33	5.9%	0.061	16.8
Damaged Diamond Pickaxe	1	1⁄33	5.9%	0.061	16.8
Enchanted Diamond Axe	1	1⁄33	5.9%	0.061	16.8

Pots

In Java Edition, each trial chambers corridor pot contains 1 item stack, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per pots	Avg.pots to break
Emerald	1–8	100⁄551	18.1%	0.817	5.5
Amethyst Shard	1–4	100⁄551	18.1%	0.454	5.5
Arrow	1–4	100⁄551	18.1%	0.454	5.5
Lapis Lazuli	1–4	100⁄551	18.1%	0.454	5.5
Iron Ingot	1–6	50⁄551	9.1%	0.318	11.0
Gold Ingot	1–6	20⁄551	3.6%	0.127	27.6
Trial Key	1–3	20⁄551	3.6%	0.073	27.6
Diamond	1–4	5⁄551	0.9%	0.023	110.2
Block of Emerald	1–3	5⁄551	0.9%	0.018	110.2
Block of Diamond	1–2	1⁄551	0.2%	0.003	551.0

Dispensers

In Java Edition, each trial chambers chamber dispenser contains 1 item stack, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per dispenser	Avg.dispensers to loot
Fire Charge	4–8	6⁄29	20.7%	1.241	4.8
Snowball	4–8	6⁄29	20.7%	1.241	4.8
Arrow	4–8	4⁄29	13.8%	0.828	7.2
Water Bucket	1	4⁄29	13.8%	0.138	7.2
Egg	4–8	2⁄29	6.9%	0.414	14.5
Lingering Potion of Healing	2–5	1⁄29	3.4%	0.121	29.0
Lingering Potion of Poison	2–5	1⁄29	3.4%	0.121	29.0
Lingering Potion of Slowness	2–5	1⁄29	3.4%	0.121	29.0
Lingering Potion of Weakness	2–5	1⁄29	3.4%	0.121	29.0
Splash Potion of Poison	2–5	1⁄29	3.4%	0.121	29.0
Splash Potion of Slowness	2–5	1⁄29	3.4%	0.121	29.0
Splash Potion of Weakness	2–5	1⁄29	3.4%	0.121	29.0

In Java Edition, each trial chambers corridor dispenser contains 1 item stack, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per dispenser	Avg.dispensers to loot
Arrow	4–8	1⁄1	100.0%	6.000	1.0

In Java Edition, each trial chambers water dispenser contains 1 item stack, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per dispenser	Avg.dispensers to loot
Water Bucket	1	1⁄1	100.0%	1.000	1.0

Trial Spawners

When all mobs have been killed, the spawner has a 50% chance of picking the trial key, in which case it will drop for all players. The other 50% of the time it will drop one of the other items for each player.

In Java Edition, each trial spawner contains 1 item stack, with the following distribution:

Item	Stack Size	Weight	Chance	Avg.per spawner	Avg.spawners to defeat
Trial Key	1	13⁄26	50.0%	0.500	2.0
Glow Berries	2–10	3⁄26	11.5%	0.692	8.7
Emerald	1–6	3⁄26	11.5%	0.404	8.7
Baked Potato	1–3	3⁄26	11.5%	0.231	8.7
Golden Carrot	1–3	1⁄26	3.8%	0.077	26.0
Ender Pearl	1	1⁄26	3.8%	0.038	26.0
Potion of Regeneration	1	1⁄26	3.8%	0.038	26.0
Potion of Strength	1	1⁄26	3.8%	0.038	26.0

Data Values

ID

Java Edition:

Bedrock Edition: