Java Edition 21w40a

This page covers a development version that has a major issue under certain conditions.

 

The dedicated server for this version has a security vulnerability in the Log4j library that could be used to perform a remote code execution exploit. It can be addressed by appending a certain JVM argument to the server startup command line.^[1]

Minecraft 21w40a

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21w40a is the fourth snapshot for Java Edition 1.18, released on October 7, 2021,^[2] that merges and renames some biomes, tweaks world generation, mob spawning, and fixes bugs.

Copper ore

• Now drop 2-5 raw copper when mining instead of 2-3.

Stonecutter

• Block of copper can be converted to 4 cut copper using stonecutter.

Axolotls

• Now only spawn in water above clay blocks in lush caves.

Cod, salmon, pufferfish, tropical fish, squid, and dolphins

• Now only spawn in water from Y=50 to Y=64.
• Additionally, tropical fishes now also spawn in lush caves at any height.

Glow squids

• Now only spawn in water blocks under Y=30.

Goats

• No longer spawn in stony peaks.

Zombies

• Now also spawn in dripstone caves again.

Biomes

• The unused height variation sub-biomes have been removed from the code and merged with their default biome variants, as following:

Removed biomes
Badlands Plateau
Bamboo Jungle Hills
Birch Forest Hills
Dark Forest Hills
Desert Hills
Desert Lakes
Giant Spruce Taiga Hills
Giant Tree Taiga Hills
Gravelly Mountains+
Jungle Hills
Modified Badlands Plateau
Modified Jungle
Modified Jungle Edge
Modified Wooded Badlands Plateau
Mountain Edge
Mushroom Field Shore
Shattered Savanna Plateau
Snowy Mountains
Snowy Taiga Hills
Snowy Taiga Mountains
Swamp Hills
Taiga Hills
Taiga Mountains
Tall Birch Hills
Wooded Hills

• Some biomes have been renamed:

Old name	New name
Giant Spruce Taiga	Old Growth Spruce Taiga
Giant Tree Taiga	Old Growth Pine Taiga
Gravelly Mountains	Windswept Gravelly Hills
Jungle Edge	Sparse Jungle
Lofty Peaks	Jagged Peaks
Mountains	Windswept Hills
Shattered Savanna	Windswept Savanna
Snowcapped Peaks	Frozen Peaks
Snowy Tundra	Snowy Plains
Stone Shore	Stony Shore
Tall Birch Forest	Old Growth Birch Forest
Wooded Badlands Plateau	Wooded Badlands
Wooded Mountains	Windswept Forest

• Non-cave biomes (e.g. savannas) no longer change with height.
• Tweaked the relative size of some biomes, to match 1.17 a bit closer.
• Increased the average size of most biomes.

Ore distribution

• Copper ore now generates between Y=-16 and Y=112, generating the most at Y=48, and increased the number of ore blobs.
• Added more unexposed diamonds.
• Decreased minimum generation height of emerald ore from Y=32 to Y=-16, and increased the number of blobs.
  • This allows deepslate emerald ore to generate again.
• Extra gold generates below Y=-48.
• Decreased minimum generation height of the upper range of iron ore from Y=112 to Y=80, and increased the number of blobs.

Monster rooms

• Increased the amount of monster rooms, especially below Y=0.

Gravel

• Now generates below Y=0, and increased the number of blobs.

Lakes

• Water lakes were removed, because aquifers could provide local water levels.

Magma blocks

• Slightly increased the frequency of underwater magma.

Villages

• Now slightly more spread out.

General

• Bedrock layers generate dependent on the world seed now.

Advancements

• Due to the removal or merging of sub-biomes, the number of biomes required to visit for the "Adventuring Time" advancement has been reduced from 42 to 31, with the following biomes now being required:

Required biomes
Badlands
Bamboo Jungle
Beach
Birch Forest
Cold Ocean
Dark Forest
Deep Cold Ocean
Deep Frozen Ocean
Deep Lukewarm Ocean
Desert
Forest
Frozen River
Jungle
Lukewarm Ocean
Mushroom Fields
Old Growth Pine Taiga
Plains
River
Savanna
Savanna Plateau
Snowy Beach
Snowy Plains
Snowy Taiga
Sparse Jungle
Stony Shore
Swamp
Taiga
Warm Ocean
Windswept Forest
Windswept Hills
Wooded Badlands

AI

• Optimized AI for axolotls, goats, hoglins, zoglins, piglins, piglin brutes and villagers.

47 issues fixed

From released versions before 1.18

• MC-128770 – Woodland mansions still generate in dark forest hills.
• MC-132306 – Snowy grass without snow near lakes in snowy biome.
• MC-133582 – Dolphins try to catch up with boat on land.
• MC-137140 – Llamas cannot spawn in shattered savanna plateau.
• MC-137956 – Lakes still generate in superflat preset "Overworld" after removing its tag.
• MC-138734 – Spawn point for seed 0, world type Buffet with badlands plateau biome is under surface, ⇒ player dies.
• MC-138782 – Stranded dolphin tries to catch the boat on the water and stops beating.
• MC-138939 – Fish and dolphins spawn in water above sea level.
• MC-152966 – Increase in villages generating in versions after 1.10.
• MC-169523 – As of 18w06a, the sand, clay and gravel blocks no longer generate around small lakes.
• MC-177016 – Some lakes in frozen biomes generate unfrozen.
• MC-190724 – Spawning in solid blocks in single biome "Badlands Plateau" world.
• MC-197688 – Mountain edge never generates.
• MC-200640 – Despite being a coastal biome, mushroom field shores don't have a warm/unique water color.
• MC-200803 – Gravelly mountains+/modified gravelly mountains placed incorrectly in the biome selection.
• MC-217906 – Large amounts of axolotls cause performance issues.
• MC-224494 – Regular dirt can generate naturally on the surface near pools.
• MC-225030 – Dungeons are extremely rare compared to in the past.
• MC-225506 – Grass blocks can generate naturally in underground pools.
• MC-225842 – Flowers can generate on large plants near lakes.
• MC-225858 – Seeds and flowers appear in ponds.
• MC-226000 – Pointed dripstone items in underground pools.
• MC-226437 – Water lakes generating in snowy tundra's can sometimes contain dark spots.
• MC-226682 – World can fail to render/load causing visual issues.
• MC-227064 – Floating grass can still generate above water lakes.
• MC-229365 – Large amounts of goats cause performance issues.
• MC-231400 – Modified badlands plateau and mountain edge don't generate and gives out invalid biome data in single biome worlds.
• MC-233661 – In some cases, sand blocks generating over lakes do not cause light updates, resulting in large dark spots.
• MC-238006 – Emerald ore and infested blocks do not generate in snowy mountain biomes.

From the 1.18 development versions

• MC-236609 – New mountain biomes use translations strings in biome selection.
• MC-236614 – Adventuring Time advancement still accepts non generating biomes.
• MC-236617 – Mountains and gravelly mountains use their 1.17.1 biome ID name.
• MC-236632 – Banners without patterns do not render properly.
• MC-236663 – Command blocks do not display command in their UI.
• MC-236736 – No relief on treasure map or explorer maps.
• MC-236894 – Foliage from specific biomes can generate in biomes they aren't meant for.
• MC-236896 – Strange mini broken aquifer walls generating commonly on the surface.
• MC-237490 – The bottom parts of aquifers aren't always surrounded by blocks which can occasionally cause them to spill into caves in ways that appear bizarre.
• MC-237586 – Entities that die outside of simulation distance remain frozen in the death animation.
• MC-237666 – Unused biomes still present in game files.

From the previous development version

• MC-237925 – Opening world from 1.12.2 (or older) in latest snapshot regenerates random chunks.
• MC-237933 – Sweet berries generate much too often.
• MC-237950 – Cave vines can generate without tip because prioritize_tip option is negated.
• MC-237951 – Cave vines can generate into water.
• MC-237962 – Entities bob their head up and down when targeting towards the player.
• MC-238104 – Blue orchid generation has decreased.
• MC-238265 – version.json contains internal revision ID instead of game version ID.