Java Edition 1.18 Experimental Snapshot 1

1.18 Experimental Snapshot 1 is the first experimental snapshot for Java Edition 1.18, released on July 13, 2021, which introduces new terrain generation and enables features from the preview data pack.

World generation

 * Caves


 * Completely overhauled.
 * Now stretch down to Y=-59.
 * The cavern now generates in 2 layers of different stone bases depending on the depth.
 * Cavern layer above Y=0 is made up of regular stone.
 * Stone transitions to deepslate from Y=0 to Y=-7.
 * Deepslate now completely replaces stone from Y=-8 to bedrock.
 * Certain types of ores and structures still generate in the deepslate layer, as well as tuff.
 * Dirt, diorite, granite and andesite do not generate in this layer.
 * Contain aquifers, bodies of water with different heights, independent of sea level (Y=63).
 * Aquifers below Y=0 sometimes generate with lava instead of water.
 * Improved old caves, adding more variation.
 * New noise caves, coming in 3 forms, cheese, spaghetti and noodle.
 * The original caves still exist with their generation slightly tweaked to better blend in with noise caves.
 * Cheese caves have large stone towers stretching from the bottom of the cave to the top.
 * Very large, often large enough to fly with an elytra.
 * Abundant with springs, aquifers and ores.
 * Spaghetti caves are long, thin caves that have small aquifers and are more similar to original caves.
 * Noodle caves are thinner, squigglier and more claustrophobic variants of spaghetti caves.


 * Mountains


 * Come in 5 sub-biomes:
 * Mountain Meadow
 * The lowest layer of a mountain that look like a flowery and colder plains, with an aqua grass color.
 * Contains grass, tall grass, dandelions, azure bluets, cornflowers, blue orchids, poppies, daisies, alliums, and dead bushes.
 * Unlike the, does not contain sweet berry bushes.
 * Only rabbits and donkeys spawn in this biome.
 * Mountain Grove
 * Reminds a snowy taiga with snow blocks instead of grass blocks.
 * The second lowest layer of a mountain.
 * Covered in snow, snow blocks, powder snow and is filled with spruce trees.
 * Rabbits, wolfs, foxes, sheeps, pigs, chickens and cows spawn in this biome.
 * Snowy Slopes
 * The second highest layer of a mountain.
 * Covered in snow, snow blocks, powder snow and ice.
 * Only rabbits and goats spawn in this biome.
 * Lofty Peaks
 * The highest layer of a mountain which will only generate if the mountain is high enough.
 * Generates if the surrounding biomes are too warm for snow capped peaks.
 * Covered in snow, snow blocks and ice.
 * Only goats spawn in this biome.
 * Snow Capped Peaks
 * The highest layer of a mountain which will only generate if the mountain is high enough.
 * Generates if the surrounding biomes are too cold for lofty peaks.
 * Covered in snow, snow blocks, ice, and packed ice.
 * Only goats spawn in this biome.


 * Ore veins
 * Long and rare ore formations.
 * Copper ore veins mixed with granite and raw copper block generate above Y=0.
 * Iron ore veins mixed with tuff and raw iron block generate below Y=0.

Blocks

 * Sculk Sensor
 * Have been re-added to the Creative Mode inventory.

Items

 * Bundle
 * Have been re-added to the Creative Mode inventory.
 * Can once again be crafted.

Mobs

 * Axolotls
 * Now only spawn in lush caves.
 * Goat
 * Now only spawn in the new mountain biomes.
 * General
 * Hostile mobs will only spawn in areas where the light level is equal 0.
 * This change only affects block-light and not sky-light.

World generation

 * Lush Caves and Dripstone Caves
 * Now generate naturally underground and inside hills or mountains.
 * Azalea trees now generate above lush caves.


 * Deep Warm Ocean
 * Now generates naturally.


 * Swamp
 * Does not generate correctly. This will be fixed in a future experimental snapshot.


 * Sub-biomes


 * Wooded hills, birch forest hills, tall birch hills, taiga hills, taiga mountains, gravelly mountains+, desert hills, desert lakes, savanna plateau, shattered savanna plateau, swamp hills, dark forest hills, ice spikes, snowy mountains, snowy taiga hills, snowy taiga mountains, modified jungle, jungle hills, bamboo jungle hills, jungle edge, modified jungle edge, giant tree taiga hills, giant spruce taiga hills, eroded badlands, badlands plateau, modified badlands plateau, modified wooded badlands plateau, and mushroom field shore biomes no longer generate naturally.
 * Ice spikes and eroded badlands will be added back in a future experimental snapshot.
 * Whether any of the other biomes listed will be re-added, or if any will be removed from the game outright, is currently unknown.


 * Ore distribution
 * The new ore distribution has been implemented, see below all the changes from 1.17 distribution to this.
 * Changed ore generation of all ores making them have a spread value like lapis lazuli ore. Some still retain a linear generation alongside a spread generation.
 * Coal ore, emerald ore, and copper ore no longer generate below Y=0.
 * Copper ore generates between the Y=0 and Y=96 and like all other ores, uses spread. It peaks at Y=48.
 * Emerald ore generates above Y=32 as a spread, peaking at Y=256 and decreasing in quantity as the altitude decreases.
 * Coal ore attempts to generate twice: once, evenly between an altitude of Y=136 and Y=256; and as a spread, peaking at an altitude of Y=96 and generating between an altitude of Y=0 and Y=192.
 * Other ores also generate differently.
 * Iron ore attempts to generate three times: once as a spread peaking at an altitude of Y=256, generating above Y=128; another as a spread peaking at Y=16 and generating with a minimum height of Y=-24 and a maximum height of Y=57, and a smaller one spreading evenly between the altitudes of Y=-64 and Y=-32.
 * Gold ore generates between the altitudes of Y=-64 and Y=32, peaking at Y=-16. The extra gold that generates in the badlands biome was left untouched.
 * Lapis lazuli ore attempts to generate twice: once, as a spread between the altitudes of Y=32 and Y=-32, peaking at an altitude of 0; and evenly between the altitudes of Y=64 and Y=-64, generating buried like ancient debris.
 * Redstone ore attempts to generate twice: once, evenly between an altitude of Y=15 and Y=-64; and as a spread, peaking at an altitude of -64 and generating below an altitude of Y=-32.
 * Diamond ore now generate as a spread, generating below Y=16 and peaking at altitudes near y=-64.


 * General
 * Terrain generation is now independent from biomes, with biomes adapting to whatever terrain they happen to generate throughout.
 * This allows for natural variation in the terrain of any individual biome, both in terms of shape and elevation.
 * For example, forests and deserts could form up on a hill without needing a special biome just for that purpose.
 * This additionally allows for smoother transitions between biomes.
 * Terrain is now smoother and more extreme.

General

 * Height limit
 * Has been increased to 384 blocks, expanding 64 blocks up and 64 blocks down, with 320 being the limit upward and -64 being the limit downward.


 * World types
 * Removed the Large Biomes and Amplified world types.

Issues

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

Trivia

 * This is the first time that the light level requirement for common hostile mob spawning gets changed for more than 10 years. The "light level 7 and below" rule was originally implemented on February 4, 2010, while the game was still in its Indev phase, and remained constant since with the exception of Java Edition Alpha v1.2.0 through Java Edition Alpha v1.2.0_02, where the restrictions were height based.
 * This is the first development version using the term "Experimental Snapshot", which starts the update development before the initial snapshots will begin, sometime in September.

Video
Video made by slicedlime: