It is now time for the first Pre-release of Minecraft 1.20.5, featuring some tweaks to Trial Chambers and Ominous Trials, as well as new advancements, a big set of technical tweaks and changes, and lots of bug fixes.

From now on, you should mostly see bugs being fixed. In addition to that, pre-releases don't follow the regular snapshot cadence of releasing on Wednesdays, so keep an eye out for the next pre-release.

Experimental Features

Trial Chambers

More consistently buried by terrain when found underground
Remade 'Chamber 6' with variations, and renamed it to 'Assembly'
Added a new trap dispenser style to chambers
Fixed various broken jigsaw connections in the corridors
Chamber Eruption:
- Stopped Tuff Bricks from spawning in the air
- Added more lights to quadrants

Ominous Trials

Mobs that can wear equipment will now often spawn with enchanted weapons and armor
- Armor enchantments include Protection IV, Projectile Protection IV and Fire Protection IV
- Weapon enchantments include Sharpness I, Knockback I, Power I and Punch I
Mobs that wear equipment no longer have a chance to drop their equipment on death
Players are now chosen 50% of the time when an Ominous Trial Spawner chooses which entity to drop projectiles on top of
- Projectiles now spawn more accurately above chosen entities

Weaving

Now more consistently spawns 2-3 cobwebs on death
Players are now affected by the movement buff through Cobwebs
- Move through Cobweb with 50% of their normal speed instead of 25%

Infested

Now has a 10% chance to spawn 1-2 Silverfish instead of 5%
Silverfish will now spawn at the center of the entity's bounding box and fling out in the direction the entity is facing

Oozing

Will only spawn slimes in a given 5x5x5 area up to the max entity cramming count

Advancements

Added Revaulting - Unlock an Ominous Vault with an Ominous Trial Key

New Features in 1.20.5-pre1

Advancements

Added the following advancements:
- Isn't it Scute? - Get Armadillo Scutes from an Armadillo using a Brush
- Snip it! - Remove Wolf Armor from a Wolf using Shears
- Good as New - Repair a damaged Wolf Armor using Armadillo Scutes
- The Whole Pack - Tame one of each Wolf variant

Changes in 1.20.5-pre1

Added support for Viossa language

Technical Changes

The Data Pack version is now 39

Data Pack Version 39

Added new item sub-predicates and loot functions
Added new terrain adaptation type for structures: encapsulate
- Density will be added all around every piece of a structure
- Ideal for structures that need to be entirely covered underground
The page limit in Written Books has been removed
The combination of max_stack_size and max_damage components is no longer allowed in commands and data pack definitions
Added a new option body in entity equipment sub-predicate to match the item in the body armor slot of an entity
The saturation_modifier field on the food component has been replaced with saturation
- saturation is the exact value added to the player's saturation level
- In respect to the former saturation_modifier, this is defined by saturation = nutrition * saturation_modifier * 2
Particle representation in commands and area effect clouds has been changed
Changed optional equipment_loot_table field in the SpawnPotentials of Monster Spawners and spawn_potentials of Trial Spawner configs
- Now named equipment instead of equipment_loot_table
- Format: object with fields
  - loot_table - A loot table used to generate the equipment
  - slot_drop_chances - An optional map of equipment slot to specified drop chance
    - Can also be a single value instead of a list to apply to all slots: e.g. slot_drop_chances: 0.0f will apply a chance of 0% to all slots
- e.g. equipment: {loot_table: "minecraft:equipment/trial_chamber", slot_drop_chances: {"head": 0.0f, "chest": 0.25f, "legs": 1.0f, "feet": 0.25f}}
- If present, rolled items from the specified loot table will be equipped to the mob that spawns
Removed Item tag minecraft:tools (overlapping with minecraft:breaks_decorated_pots)
Added Entity Type tag minecraft:punchable_projectiles for projectiles which should be able to be punched and deflected toward the direction the player is looking
Added Enchantment tag minecraft:tooltip_order controlling which order Enchantments are listed in tooltips

Modified loot functions

`set_contents`

Unused field type has been removed
Added new mandatory field component:
- Describes target component to be filled with items
- Existing contents will be replaced
- Allowed values: container, bundle_contents, charged_projectiles
- bundle_contents and charged_projectiles will ignore empty stacks

`set_custom_data`

Field tag now accepts both SNBT data written as a string (existing format) and unflattened tags

New Loot Functions

`modify_contents`

Apply modifier function to every item inside a component
If component does not exist, it will not be added
Fields:
- conditions- list of conditions to filter this function
- component - target component
  - Allowed values: container, bundle_contents, charged_projectiles
- modifier - function or list of functions to be applied to every item inside container

`set_item`

Replaces item type of item stack without changing count and components
Fields:
- conditions - list of conditions to filter this function
- item - new item type

`filtered`

Applies sub-function only to items that match item predicate
Fields:
- conditions - list of conditions to filter this function
- item_filter - item predicate used to match items
- modifier - functions to apply to matching items

`set_custom_model_data`

Sets custom_model_data component
Fields:
- conditions - list of conditions to filter this function
- value - integer number provider

New Item Sub-predicates

General rules of component predicates:

Unless otherwise specified, a field in predicate with the same name as a field in component that matches (i.e. has the same name as predicate) will match that field value
Those fields will usually have the same type as in the components, but will be optional.
Exceptions:
- List fields will be replaced with collection matchers (see below)
- Integer and float fields will be replaced with ranges
- Registry ids will be replaced with a type that accepts id, list of ids or a tag

Collection matcher

Collection matcher is a shared part of predicate used for matching collections. Every instance of this matcher will have same fields with same functionality, with only difference being type of matched element Fields:

size - integer range to match against collection size
contains - a list of element predicates
- All conditions must match for predicate to pass
- Not all elements in tested container have to be matched
- Elements can be in any order
- Single element can match multiple predicates
- Examples (when matching item stacks):
  - {contents:[{item:diamond}]} - will match when there is at least one diamond item
  - {contents:[{item:diamond}, {item:dirt}]} - will match when there is at least one diamond item and at least one dirt item
count - a list of matchers on element counts
- Entry fields:
  - test - element matcher
  - count - optional integer range to check against number of elements passing test
- Examples (when matching item stacks):
  - {count:[{count:3,test:{items:diamond}}]}} will match only when there are exactly 3 stacks of diamonds (no matter the stack size)

`container`

Matcher for container component (like shulker box)
Fields:
- items - optional collection matcher
  - Note: empty items are ignored. That means container~{items:{size:3}} will only pass if there are exactly 3 non-empty stacks in container

`bundle_contents`

Matcher for bundle_contents component
Fields:
- items - optional collection matcher

`firework_explosion`

Matcher for firework_explosion component
Fields
- shape - optional matcher for shape, same values as shape field in minecraft:firework_explosion component
- has_trail - optional boolean
- has_twinkle - optional boolean

`fireworks`

Matcher for fireworks component
Fields:
- explosions - optional collection matcher for firework_explosion predicates
- flight_duration - optional integer range check for flight duration
Example: minecraft:fireworks~{explosions:{contains:[{shape:small_ball}]}}] - matches if firework has at least one explosion with small_ball shape

`writable_book_content`

Matcher for writable_book_content component
Fields
- pages - optional collection matcher for strings (matching only unfiltered contents of page)

`fireworks`

Matcher for written_book_content component
Fields
- pages - optional collection matcher for chat components (matching only unfiltered contents of page)
- author - optional string value
- title - optional string value (matching only value)
- generation - optional integer range check for generation
- resolved - optional boolean

`attribute_modifiers`

Matcher for attribute_modifiers component
Fields:
- modifiers - optional collection matcher for following entries with following fields:
  - attribute - optional id, list of ids or tag for attribute to be matched
  - id - optional UUID
  - name - optional string
  - amount - optional double range check
  - operation - optional operation type (same values as operation field from attribute_modifiers component)
  - slot - optional applicable slot type (same values as slot field from attribute_modifiers component)

`trim`

Matcher for trim component
Fields:
- material - optional id, list of ids or tag for material to be matched
- pattern - optional id, list of ids or tag for pattern to be matched

Particle representation

Particle options in commands and in fields like Particles in Area Effect clouds now use the same representation as worldgen files (like existing biomes' ambient particle settings)
For example, command /particle minecraft:dust 1.0 0.0 0.0 2.0 ... becomes /particle minecraft:dust{color:[1.0, 0.0, 0.0], scale:2.0} ...
The syntax for particles without extra options (like minecraft:villager) remains unchanged
Changes to block particles (minecraft:block, minecraft:block_marker, minecraft:falling_dust, minecraft:dust_pillar) options:
- Field value has been renamed to block_state
- Field block_state now also accepts plain block name to represent default block state
- Example transformations:
  - minecraft:block minecraft:redstone_lamp[lit=true] -> minecraft:block{block_state: {Name: "minecraft:redstone_lamp", Properties: {lit: "true"}}}
  - minecraft:block minecraft:diamond_block -> minecraft:block{block_state: "minecraft:diamond_block"}
Changes to minecraft:item options:
- Field value has been renamed to item
- Field item now also accepts plain item name to represent item stack with default components
- count field is now ignored
- Example transformations:
  - minecraft:item minecraft:dirt -> minecraft:item{item: {id: "minecraft:dirt"}}
  - minecraft:item minecraft:dirt -> minecraft:item{item: "minecraft:dirt"}
Changes to dust_color_transition options:
- Field fromColor has been renamed to from_color
- Field toColor has been renamed to to_color
- Example transformation: dust_color_transition 1.0 0.0 0.0 0.5 0.0 1.0 0.5 -> dust_color_transition{from_color: [1.0f, 0.0f, 0.0f], scale: 0.5f, to_color: [0.0f, 1.0f, 0.5f]}
Changes to entity_effect options:
- Field value has been renamed to color
- Field color now also accepts list of floats representing RGBA color

Fixed bugs in 1.20.5 Pre-Release 1

MC-165435 Can't trigger flying mode in creative while standing in the middle of 2×2 magma block bubble column
MC-188497 AngerTime and AngryAt cannot be set on summon
MC-207353 Ghast fireballs and wind charges can't be redirected in melee if the attack does 0 damage
MC-263315 Attack Target of hoglins/zoglins can't be detected by /execute on target
MC-264456 Entity targeted by frogs and axolotls can't be detected by /execute on target
MC-265390 Forceload Command provides wrong output
MC-267934 Sending ClientboundTransferPacket followed by disconnect just kicks the player
MC-268000 The client crashes when using /give to give players a skull
MC-268346 Jump can be used with generic.jump_strength set to 0 resulting in a speed boost
MC-268947 Flying cannot be initiated reliably when the minecraft:generic.gravity attribute is increased
MC-269191 Old villagers can't trade
MC-269192 Breeze is not affected by the 'execute on target' command
MC-269266 Area effect cloud particles from creeper explosions are incorrectly tinted
MC-269320 Books with more than 100 pages get cut off when upgraded
MC-269357 Flow and guster banner pattern descriptions display as raw translation strings
MC-269366 Mace doesn't break Decorated Pots unlike other tools
MC-269496 You don't get any damage if you fight against the breeze in a minecart or in a boat
MC-269501 The text above the hotbar has no background, even when the "Text Background" setting is "Everywhere" in spectator mode
MC-269508 Player keeps vertical momentum when jumping when landing on the ground from sonic boom
MC-269609 Wind charges can harm the ender dragon while it perches atop the end portal, unlike arrows and tridents.
MC-269610 Wind charges have the capability to harm the wither when it has reached half health or less
MC-269680 Game crashes when trying to save after modifying item stack to have a max_stack_size below its current stack size
MC-269707 Brewing stand slots have artificial maximum stack size of 64
MC-269765 Mace damage does not reset after a hit while still falling
MC-269933 limit_count item modifier can create overstacked items
MC-269947 Clicking spam with Mace causes very high damage
MC-269948 The subtitle for the "minecraft:event.mob_effect.raid_omen" sound event displays as a raw translation string
MC-269949 New "Raid Omen" effect texture is using Programmer Art Evoker as base
MC-269954 Striking non-living entities with a mace enchanted with Wind Burst propels the player upward, even when they are flying
MC-269955 When flying in creative mode, hitting ender dragons with a mace enchanted with Wind Burst pushes the player upward, unlike when attacking other mobs
MC-269959 "Not a list" printed to console when loading into a world
MC-269961 Non-player entities with the Weaving effect can't walk through Cobweb at normal speeds
MC-269963 Bad Omen is not removed when experimental features are disabled
MC-269974 Mobs with the weaving effect, when dying, are unable to replace replaceable blocks with cobwebs
MC-269976 Wind Burst book available from villager trading
MC-269977 Wind Burst enchantment is obtainable in Enchanting Table
MC-269980 Wind Burst enchantment triggers from normal attacks rather than smash attacks
MC-269993 Hitting wind charges using mace with Wind Burst creates very high upwards momentum
MC-269999 Potions of Infestation, Oozing and Weaving can be obtained without experimental features enabled
MC-270001 The particle 'minecraft:item minecraft:air' crashes the client
MC-270004 Giving yourself an item with a Wind Burst enchantment level higher than 3, then hitting certain entities crashes the game
MC-270005 Mace smash attack can be done multiple times from a single fall
MC-270009 Entities with the infested effect can spawn silverfish without actually being hurt
MC-270048 Vault textures are inconsistent
MC-270060 The glowing parts of trial spawner textures are inconsistent
MC-270094 Fletcher sells new tipped arrows without experimental features enabled
MC-270099 Killing a mob with Weaving effect places cobwebs even if mobGriefing is disabled
MC-270119 The contents slot for the /item command does not function with shot arrows, tridents, and fireballs
MC-270125 Wind Burst can be obtained from chest and fishing loot
MC-270158 Wind Burst activates while mace is on cooldown
MC-270161 Wind burst enchantment is significantly stronger on vehicle entities
MC-270201 Fishing rod line does not account for the scale attribute in third-person
MC-270236 area_effect_cloud and lingering potions causing potion_contents.custom_color to be slightly transparent
MC-270412 Wind charge item crash on non-experimental worlds.
MC-270475 Container component slot -1 crash

Minecraft 1.20.5 Pre-Release 1