Where they are and what they look like
Trial chambers generate underground, roughly between Y negative 40 and Y negative 20, built from copper and tuff bricks. They are large connected room complexes rather than a single corridor, and the entrance is usually a stairwell or a shaft opening into a big central chamber.
Because they sit in deepslate territory, the trip down is the same as any deep mining trip: bring torches, blocks, food and a water bucket, and expect to deal with deepslate, lava pockets and the occasional cave spider. A trial chamber is not a place to arrive with an iron sword and half a stack of bread.
Trial spawners
Each room has a trial spawner, a cage-like block that activates when a player comes close. It spawns waves of mobs, and when you clear the waves it goes quiet and rewards you. The mobs depend on the room: zombies, skeletons, bogged, spiders, slimes, silverfish and breezes all show up in different chambers.
After the waves are cleared the spawner enters a cooldown of roughly 30 minutes before it can be triggered again. You cannot farm it by standing there, so treat each chamber as a one pass event and clear it properly the first time.
Keys and vaults
Clearing a spawner drops trial keys. Those keys open the vaults scattered around the chamber, and each vault holds loot. A trial key opens a normal vault, and an ominous trial key opens an ominous vault. Vaults are consumed per player, so in a group everyone gets their own pull rather than competing for one chest.
- Search every room before you leave. Keys are useless once you have walked away from the vaults.
- Vaults are not chests. You cannot break them for the contents, and the reward comes out when you use a key on them.
- Normal vault loot is decent: enchanted books, diamonds, emeralds, and the usual supply of food and blocks.
Ominous trials
Drink an ominous bottle to gain Bad Omen, then trigger a trial spawner. The Bad Omen converts into Trial Omen, and the chamber switches to ominous mode: the spawners become ominous spawners, the mobs are tougher, and the keys you get are ominous keys for ominous vaults.
Ominous bottles come from raid captains, the pillager with the banner who leads a patrol or a raid. If you see a patrol, killing the captain is worth the fight, and a raid you were going to do anyway is a reliable supply.
The mace and the heavy core
The mace is crafted from one heavy core and one breeze rod. The heavy core only comes from an ominous vault, at a low chance, so expect to run several chambers before you get one. The breeze rod comes from breezes, and one rod also breaks down into four wind charges.
The mace is the reason to care. Its damage scales with the distance you fall before hitting, and a falling attack negates the fall damage you would otherwise take. Jumping off a pillar and landing on a mob is the intended use, and it is one of the most satisfying things in the game once you get the timing.
Its enchantments are all mace specific: Density increases damage per block fallen, Breach reduces the target's armour effectiveness, and Wind Burst launches you back into the air on a successful smash so you can chain hits.
A run that goes well
The order that works is boring and reliable. Clear the entrance room first and light it, so you have somewhere safe to retreat to. Work outward one chamber at a time instead of running through the complex, because pulling two spawner rooms at once is how a good run turns into a death.
- Clear a room, collect the keys, open the vaults in that room, then move on. Keys carried to the next room are fine, keys left behind are wasted.
- Keep the water bucket in your hotbar. It stops fall damage from the upper walkways and it puts out the fire from any lava pockets you uncover.
- Drink the ominous bottle only when you are standing next to a spawner you are ready to trigger, and only after you have cleared the normal version of that room.
- Bank your loot in an ender chest if you brought one. A trial chamber is deep enough that dying means a long walk back through mob filled tunnels.
Bring a stack of blocks you do not mind losing. Half the chambers have gaps, broken walkways and copper grates that are easier to bridge than to climb around, and a trial chamber with no blocks is a trial chamber you explore at half speed.
Breezes and wind charges
Breezes do not melee. They fire wind charges that knock you back, and they are fast and hard to corner. Fighting one in an open room is miserable; fighting one with a wall behind you is manageable. Wind charges are also useful outside the chamber: they launch you, they break fragile blocks, and they are the cheapest way to move vertically without a water bucket.
Bring a shield, keep your back to a wall, and do not let a breeze knock you into a room full of other mobs. The chamber is designed to punish exactly that.