Caves & Cliffs, also called the Underground Update, is a major two-part update for Minecraft’s Java and Bedrock editions released in 2021. The update introduces expanded cave and mountain systems, new mobs, items, blocks, and significant changes to world generation.
Release Dates:
- Part I: June 8, 2021
- Part II: November 30, 2021
Versions:
- Java Edition 1.17 (Part I), 1.18 (Part II)
- Bedrock Edition 1.17.0 (Part I), 1.18.0 (Part II)
Alternate Name: Underground Update
Overview:
- Part I: Focused on new blocks, mobs, and items including axolotls, goats, glow squids, and amethyst.
- Part II: Brought large-scale changes to terrain and world generation including taller mountains, deeper caves, and new cave types.
Development History:
- Announced during Minecraft Live 2020.
- Split into two parts due to content volume and team health considerations.
- Certain features, including the Deep Dark biome and sculk blocks, were postponed to later updates (The Wild Update).
Java Edition Development:
- Part I: Started with snapshot 20w45a (Nov 4, 2020), pre-release May 27, 2021, release candidate June 4, 2021.
- Part II: Began with 1.18 Experimental Snapshot 1 (July 13, 2021), pre-release Nov 11, 2021, release candidate Nov 25, 2021.
Bedrock Edition Development:
- Part I: Started with beta 1.16.200.52 (Oct 28, 2020). Many features were behind the experimental toggle.
- Part II: Continued with beta 1.17.30.23 (Aug 25, 2021).
Education & China Editions:
- Part I features released for Education Edition 1.17.30 (Nov 2, 2021).
- Part II features released for Education Edition 1.18.32 (Aug 9, 2022).
- China Edition: Part I (Jan 21, 2022), Part II (Aug 27, 2022).
Additions
Blocks
- Azalea & Flowering Azalea: Found in lush caves; can be grown using bone meal on moss.
- Azalea Leaves & Flowering Leaves: Part of azalea trees.
- Calcite: Surrounding amethyst geodes and stony peaks.
- Candle: Crafted from honeycomb and string; can be lit, dyed, and placed on cakes.
- Cave Vines & Glow Berries: Grow in lush caves; can be harvested for food.
- Big & Small Dripleaf: Platforms that tilt when entities stand on them.
- Dripstone Block & Pointed Dripstone: Used to grow stalactites/stalagmites in dripstone caves.
- Hanging Roots: Found under azalea trees.
- Lightning Rod: Crafted from copper to redirect lightning.
- Moss Block & Moss Carpet: Spread using bone meal.
- Powder Snow: Causes slow movement and freezing damage.
- Rooted Dirt: Found near azalea trees.
- Sculk Sensor: Technical block for detecting vibrations (commands only).
- Smooth Basalt, Spore Blossom, Tinted Glass, Tuff: Various underground blocks.
Amethyst Geode Blocks:
- Amethyst Bud, Amethyst Cluster, Block of Amethyst, Budding Amethyst.
Copper Blocks:
- Copper Ore, Deepslate Copper Ore, Copper Block, Cut Copper (stairs/slabs).
Deepslate Blocks:
- Deepslate, Infested Deepslate, Cobbled/Polished Deepslate, Deepslate Bricks/Tiles/Chiseled variants.
Raw Mineral Blocks:
- Raw Iron, Raw Gold, Raw Copper.
Items
- Amethyst Shard: Used for spyglass and tinted glass.
- Bucket of Axolotl: Captures and transports axolotls.
- Copper Ingot: Crafting material for blocks, lightning rods, spyglass.
- Glow Ink Sac: Drops from glow squids; used for glowing signs and item frames.
- Powder Snow Bucket: Places powder snow.
- Spyglass: Crafted from amethyst shard and copper; zooms in on distant locations.
- Raw Iron, Gold, Copper: Obtained from mining ores.
- Music Disc “otherside” by Lena Raine.
Spawn Eggs:
- Axolotl, Glow Squid, Goat.
Mobs
- Axolotl: Found in lush caves; aids in underwater combat; comes in 5 colors (blue rare).
- Glow Squid: Spawns in dark underwater areas; drops glow ink sac.
- Goat: Found in mountain biomes; can ram entities; normal and screaming variants.
Non-Mob Entities
- Glow Item Frame: Displays items glowing in the dark.
- Marker (Java Edition only): Server-side technical entity for map-making and data packs.
World Generation
Ore Distribution & Cave Types:
- Stone layer above Y=0; deepslate layer below Y=8.
- Caves: Cheese (large), Spaghetti (long/thin), Noodle (thin/small).
- Aquifers generate independently of sea level.
- Updated ore generation for coal, copper, iron, gold, lapis, redstone, diamond, emerald.
Biome-Specific Generation:
- Caves:
- Dripstone Caves: Dripstone, pointed dripstone, copper, water.
- Lush Caves: Moss, azalea, dripleaf, spore blossoms, glow berries, axolotls.
- Mountains:
- Jagged Peaks: Goats, snow, stone.
- Frozen Peaks: Goats, snow, ice, packed ice.
- Snowy Slopes: Goats, rabbits, snow, powder snow.
- Grove: Snow blocks, powder snow.
- Meadow: Flowers, tall grass, cold grassy terrain.
- Stony Peaks: Stone, gravel, calcite.
Generated Structures:
- Amethyst Geode
- Azalea Tree
Soundtrack
- Lena Raine: Stand Tall, Left to Bloom, Wending, Infinite Amethyst, One More Day, otherside
- Kumi Tanioka: Floating Dream, Comforting Memories, An Ordinary Day
- Tracks are biome-specific or main menu background music.
Changes
- Ore textures updated for colorblind accessibility.
- Iron and gold ores drop raw minerals instead of blocks when mined without Silk Touch.
- Mineshafts updated with oak logs/fences and chains.
- Copper oxidation can be scraped or de-waxed with an axe.
Further Revisions
Java Edition:
- 1.17.1: Minor fixes and mechanic adjustments.
- 1.18.x: Fog tweaks, /placefeature command, custom world generation, spectator toggle, bug fixes.
Bedrock Edition:
- 1.17.x & 1.18.x: Bug fixes, experimental features, candle addition, parity with Java, world generation improvements.
Videos
Official Trailers:
- Part I: June 8, 2021
- Part II: November 30, 2021
Showcases (Java Edition):
- 1.17: “What’s New”, Technical News, Custom World Changes
- 1.18: “What’s New”, Ore Distribution, Texture Updates, Technical News
Other Content:
- Dev Diaries on world generation, mobs, blocks, community collaboration, and gameplay changes.
Trivia
- Developers explored real caves for design inspiration.
- Concept art inspired by Adventure Time episode Diamonds and Lemons.
- Deep Dark, sculk blocks, the warden, goat horns, archaeology, and bundles were postponed to later updates.
- Trailer easter eggs: Capricornus constellation (sea-goat) and Necromancer laugh from Minecraft Dungeons.