Just Trial Spawners

A full-featured Forge 1.20.1 backport of Minecraft 1.21's Trial Spawner and Vault. Brings trial spawners, vaults, breeze, bogged, wind charges, ominous mode, trial-themed mob effects, and mace enchantments to your 1.20.1 world. This does NOT add any worldgen, it is primarily directed at packmakers.

Why Another Trial Chamber Backport?

Just Trial Spawners was built to be a production-ready, modpack-friendly backport with faithful 1.21 behavior. It includes the full state machine, all the mob effects, all the enchantments and the ominous item spawner system.

Features

Trial Spawner

A complete recreation of 1.21's trial spawner with the full state machine:

Detects players within a configurable range
Spawns mobs in waves with per-player scaling
Ejects rewards on completion (consumables + keys)
Transforms into ominous mode when a player with Bad Omen approaches
Ominous item spawner system — periodically drops items above players/mobs during the fight
Right-click with a spawn egg to set the next spawn mob type
Custom item renderer shows a spinning mob preview in your hand and in GUIs
Tooltip displays the currently configured mob

Vault

Trial Key / Ominous Trial Key activation
Per-player reward tracking — each player gets one reward per vault
Ominous vault variant with upgraded loot
Proper cutout rendering for transparent textures

Mobs

Breeze — Aerial mob with authentic 1.21 AI: long jump, slide, shoot wind charges, stuck detection
Bogged — Skeleton variant that shoots poison arrows; shearable for mushrooms via datapack-configurable loot table
Wind Charge / Breeze Wind Charge — Projectile entities with authentic 1.21 knockback physics (eye-height direction vectors, line-of-sight falloff)

Items

Trial Key / Ominous Trial Key
Breeze Rod — Dropped by breezes, crafts into wind charges
Wind Charge — Throwable projectile that creates a wind burst explosion and triggers redstone components (buttons, levers, trapdoors, doors, fence gates)
Ominous Bottle — With amplifier system (I-V); higher amplifiers grant longer Bad Omen duration (up to 10 minutes)
Breeze / Bogged Spawn Eggs

Mob Effects (all with custom textures)

Trial Omen — Converted from Bad Omen at trial spawners; activates ominous mode
Wind Charged — Creates a wind burst explosion on death
Weaving — Spawns cobwebs around the entity on death
Oozing — Spawns slimes on death
Infested — Chance to spawn silverfish when hit

Enchantments

Density (I-V) — +1 damage per level; incompatible with Sharpness/Smite/Bane
Breach (I-IV) — Bypasses armor effectiveness via damage multiplier
Wind Burst (I-III) — Triggers a wind burst explosion on hit (treasure-only enchantment)

Creative Tab

The Just Trial Spawners creative tab includes:

All blocks, items, and entities
Pre-configured trial spawners for 36+ hostile mobs (zombie, skeleton, creeper, spider, cave_spider, enderman, witch, slime, magma_cube, blaze, ghast, wither_skeleton, stray, husk, drowned, zombie_villager, phantom, pillager, vindicator, evoker, ravager, vex, guardian, elder_guardian, shulker, hoglin, zoglin, piglin_brute, piglin, zombified_piglin, endermite, silverfish, warden, breeze, bogged, wither)
All 5 amplifier variants of the Ominous Bottle

Commands

Admin-only commands for configuring trial spawners:

/trialspawner edit                              - Edit held trial spawner using a GUI
/trialspawner edit <pos>                        - Edit a placed trial spawner
/trialspawner give <entity> [total] [sim] [tb]  - Give a pre-configured spawner item
/trialspawner addmob <pos> <entity> [weight]    - Add a mob to a placed spawner
/trialspawner setconfig <pos> <key> <value>     - Set a config value
/trialspawner info <pos>                        - Show current configuration
/trialspawner clearmobs <pos>                   - Clear all spawn potentials

Configuration

Server-side config located at config/justtrialspawners-server.toml:

[trial_spawner]
    # Cooldown in ticks after trial spawner completes (default 36000 = 30 minutes)
    cooldown_ticks = 36000
    # Player detection range in blocks
    detection_range = 14
    # Mob spawn range around the spawner
    spawn_range = 4
    # Enable ominous trial spawner mode (triggered by Bad Omen)
    ominous_enabled = true

[wind_charge]
    # Multiplier for wind charge knockback strength
    knockback_multiplier = 1.0

License

Released under the MIT License. You are free to use Just Trial Spawners in any modpack, private or public, without permission.

Credits

Mojang — for the original 1.21 Trial Chamber features
Breakin Blocks — development and backport
FTB Team — FTB Library (NBT editor integration)
Architectury API Team — Architectury API

Source & Issues

Found a bug? Want to contribute? Visit the GitHub repository.