Java Edition 1.18 experimental snapshot 2

1.18 experimental snapshot 2 [sic] is the second experimental snapshot for Java Edition 1.18, released on July 20, 2021, which makes numerous changes to world generation and mob spawning functionality related to spawners.

Additions

 * Tags
 * Spawners now have a new "CustomSpawnRules" tag, which lets players override the spawn rules of the spawned mob.
 * In the tag, players can specify "BlockLightLimit", which indicates the highest block-light the spawners will spawn mobs at.

Mobs

 * General
 * Zombie, skeleton, spider, and cave spider spawners now spawn mobs up to block-light level 11.

World generation

 * Beaches
 * Beaches are generally wider.
 * In some places there is a chance where no beaches generate at all, to provide some variation.


 * Extreme Hills
 * Renamed mountains to extreme hills, and gravelly mountains to gravelly hills.


 * Mountains
 * Sheep now spawn in meadows.
 * Rabbits now spawn more frequently in meadows.
 * Donkeys now spawn less frequently in meadows.
 * Blue orchid no longer spawns in meadows.
 * Meadows sometimes spawn a lone oak or birch, often with a bee nest.
 * Hostile mobs now spawn in the new mountain biomes.
 * Infested stone now generate in the new mountain biomes.


 * Ore distribution
 * Emerald ores now generate in the new mountain biomes.


 * Ore veins
 * Made ore veins slightly larger and more frequent.


 * Biomes
 * Re-added ice spikes and eroded badlands.


 * Swamp
 * Swamps now generate properly.


 * Lush Caves
 * Are now slightly smaller and slightly less common.


 * General
 * Biome placement is a bit smoother and less noisy. Fewer microbiomes dotting the terrain. Biomes tend to be a bit larger and less fragmented.
 * Underground biomes interfere less with surface biomes. They can still leak out of cave entrances sometimes.
 * Increased the height of some of the peaks.
 * Now can rarely reach up to Y=260.
 * Slightly increased the chance of finding large areas with flat terrain.
 * Structures now mostly show up in the right biomes.
 * Toned down the megacave entrances a little bit, and made them less likely to go all the way down to deepslate level.
 * Made cheese caves a little bit smaller on average, and a bit less likely to intersect the surface.
 * Reduced the chance of sand and gravel being placed in such a way that they immediately fall down on generation.
 * Some are now replaced with sandstone or stone.

General

 * Cloud
 * Raised cloud level from 128 to 192.

Trivia

 * Unlike 1.18 Experimental Snapshot 1, the title of this version is written in lowercase.

Issues

 * This version is not supported on the bug tracker, and therefore issues affecting it will be resolved as "Invalid".

Video
Video made by slicedlime: