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Minecraft trial chambers explained - spawners, keys, vaults, and more

Minecraft trial chambers are a challenging underground structure, but the trial is worth the effort thanks to valuable trial vault rewards.

Mojang's Brandon wields an axe in front of a copper bulb in one of the Minecraft trail chambers.

What are Minecraft trial chambers? Over the years, Mojang has added more and more to our underground experience in Minecraft, with awe-inspiring cave systems added with the Caves and Cliffs update in 2021, and amethyst geodes and Ancient cities for you to stumble across while exploring. There are of course Strongholds to look out for underground too, and all those valuable ores. In 2024, Trial Chambers were another massive and exciting structure added to your underground Minecraft adventures.

These vast structures were announced during Minecraft Live 2023, and added with the Minecraft 1.21 update Tricky Trials. Alongside an expansion to the family of copper blocks, giving Minecraft copper ore more uses than ever, these Trial Chambers added new mobs, new combat mechanics, and new trial vaults, a way of earning exclusive and rare loot.

Minecraft trial chambers: two minecraft players stand inside the copper corridor of a trial chamber.

Minecraft Trial Chambers

Minecraft trial chambers give one or more players the chance to practice their skills against a controlled onslaught of Minecraft mobs. The number of mobs that spawn is relative to the number of players present, and once all have been defeated, the trial is over and the player is rewarded multiple vault keys.

A Minecraft trial explorer map trade offered by a Cartographer villager.

How to find trial chambers

These sprawling structures can be found below y-level zero, and can vary in size. They also weave their way through various levels, so you could be right underneath a corridor without knowing it.

While Trial Chambers can of course be found while mining underground, you can also find them with certainty with a Trial Chamber explorer map. To get one of these, all you need to do is level up a cartographer villager to Journeyman for a chance to see this map as a trade.

Two Minecraft players look at a new trial spawner, found inside Minecraft trial chambers.

Minecraft Trial Spawners

Mob spawners: you either love them or hate them. They’re great for XP farms, but we’ve never been big fans of stumbling upon a skeleton dungeon or a cave spider spawner. Thankfully, these new trial spawners are slightly less terrifying.

Spread generously throughout trial chambers, trial spawners can spawn a range of different hostile Minecraft mobs, but you can tell which one it is by the blocks on the ground around it. For example, a trial spawner surrounded by ice blocks tells you that Strays are going to appear.

What’s so special about trial spawners, though, is that they don’t keep chucking endless killer mobs at you. As these are for training purposes, the number of mobs that spawn depends on how many people are training. No matter how many of you there are, though, there’s still a limit to how many mobs the spawner generates before it pauses for a time, giving you a breather from combat. Successfully defeat all of the mobs a spawner throws at you, and it ejects a trial key as your reward.

Ominous trials

If you’re finding regular trials a little too easy, you can take things up a notch with ominous trials, which pit you against more powerful mobs. To trigger an ominous trial, you must enter the chamber with the Bad Omen status effect. This is either cast upon you by killing a pillager captain, but the best way to get the status effect in this case is to drink an ominous bottle, found as rewards from standard trials.

While ominous trials are considerably harder, you are rewarded greatly for success with better, and even exclusive, loot.

A player holds a trial vault up to an ominous trial vault in a Minecraft trial chamber.

Trial keys and trial vaults

Upon completion of a trial, each spawner expels a trial key that can be used once by every player present. These trial keys are used on trial vaults, also found around the chambers. Upon using a key, a bunch of random items from the vault loot pool are given out. Some of the loot available includes ominous bottles, golden apples, smithing templates, and diamond tools.

After a successful ominous trial, players instead receive ominous keys. The rewards for this are far more valuable, but are also the only way of obtaining a Heavy Core, one of the ingredients for making a Minecraft Mace.

Ominous vaults can be determined from standard vaults by approaching them with a key in hand. The skull on the front of the vault opens it mouth, and the color of the bar beneath is changes. A turquoise bar (the color of oxidized copper) can be seen on an ominous vault, while a copper bar appears on a standard one. If a key is not working on a vault, you are probably using the wrong key.

A Minecraft chest in front of a copper bulb in the depths of a Minecraft trial chamber.

Trial chamber chest loot

Trial chambers are filled to the brim with loot as, alongside these precious vaults, there are also standard chests, barrels, and decorative pots scattered around. Since trial chambers are procedurally generated, their number and where you’ll find them is always a surprise, but they can contain loot like tools and weapons, Wind Charges, and even Eye of Ender.

Mojang's Magnus fights a Minecraft Breeze, a mob that appears in Minecraft trial chambers.

The Breeze mob

The Breeze is an exclusive mob to trial chambers, and does not spawn anywhere in the rest of the world. This sort of hostile mob fires gusts of wind that explode on impact. The good news is that these projectiles don’t cause damage when they explode, but if the ball of wind hits you directly, it does do some damage. We’ve got more on this new Minecraft mob in our Minecraft Breeze guide.

Two Minecraft players look up at the new Tuff blocks that can be found in Minecraft trial chambers.

Trial chamber blocks

The Minecraft copper ore has always been one with relatively limited uses – well, until the 1.21 update, that is. The Trial Chamber is made up from the family of copper blocks, including doors, trapdoors, and grates. These can all be crafted from copper ore, but they can also simply be looted from Trial Chambers if you want to build your next Minecraft house from them.

The copper bulb can also be found in Trial Chambers, a unique light block that dims with increased oxidization. Use an axe on an oxidized bulb to bring it back to its original brightness – and don’t forget you can use honeycomb to wax it and prevent further oxidization.

The Tuff block also received some new variants with the introduction of Trial Chambers, including a stunning chiseled block.

That’s everything you need to know about Minecraft trial chambers, trial keys, and trial vaults. With so much amazing loot to pick up inside, we’d certainly recommend giving one a try, but make sure you’ve got some Netherite armor on – or at least Minecraft diamond armor. If you need some help, check out our guide to hosting a Minecraft server if you want to tackle your first trial with friends.