Minecraft Wiki
Minecraft 20w45a
Java Edition 20w45a.png

Java Edition



Release date

November 4, 2020

Snapshot for



Client (.json)

Obfuscation maps


Protocol version

 dec: 1073741829
 hex: 40000005

Data version


20w45a is the first snapshot for Java Edition 1.17, released on November 4, 2020,[1] which adds the first Caves & Cliffs features.



Amethyst Bud
  • Grows from budding amethyst, which is found in amethyst geodes.
  • Starts out small, but grows into medium after a while, large after even more time and eventually becomes an amethyst cluster.
  • Unlike crops, each growth stage is a separate block instead of a block state.
  • Drops nothing if broken in its premature stages, even with Silk Touch.
Amethyst Cluster
  • The final, mature stage of the amethyst bud, which grows from budding amethyst in amethyst geodes.
  • Drops amethyst shards if broken, in an amount affected by Fortune, but can also be picked up with Silk Touch.
  • Emits a light level of 5.
Block of Amethyst
  • A block found in amethyst geodes.
  • Unlike the budding amethyst, the block of amethyst can be obtained when mined.
  • Can also be crafted with 4 amethyst shards.
Budding Amethyst
  • Generates amethyst crystals on any of its sides (if next to a water source block or air, and if the side is not against another block), in a given time.
  • Cannot be obtained when mined, even with Silk Touch, and does not drop anything.
  • Breaks immediately if pushed by a piston or sticky piston.
    • Cannot be pulled by sticky pistons.
  • Generates in amethyst geodes.
  • An off-white stone that generates in geodes, between tuff and amethyst.
  • Crafted with honeycomb and string.
  • Come with 16 dyed types and a yellowish non-dyed type.
  • Can be lit by any item that produces fire.
  • Up to 4 can be placed in a single block, similar to sea pickles, for a maximum light level of 12.
    • Only candles of the same color can be placed on the same block.
  • Only one can be placed on an uneaten cake and lit.
    • If any of the cake is consumed the candle pops off.
  • Can be placed, but cannot be lit, underwater.
Copper Block
  • Can be crafted with 9 copper ingots, and can also be crafted back into 9 copper ingots.
  • Oxidises and changes texture to a turquoise-green over time.
  • Can be stopped from oxidizing by combining it with a honeycomb to create a waxed copper block.
  • Can be crafted into cut copper.
Copper Ore
  • Generates randomly underground in small blobs, but this has been confirmed to be a placeholder.
  • Has the same rarity as iron.
  • Generating starts at the same minimum level(s) as iron.
  • Can be smelted into a copper ingot.
Cut Copper
  • Can be made into stair and slab variants.
  • Oxidises and changes texture over time.
  • Can be stopped from oxidizing by combining it with a honeycomb to create waxed cut copper.
Cut Copper Slab
  • Oxidises and changes texture over time.
  • Can be stopped from oxidizing by combining it with a honeycomb to create a waxed cut copper slab.
Cut Copper Stairs
  • Oxidises and changes texture over time.
  • Can be stopped from oxidizing by combining it with a honeycomb to create waxed cut copper stairs.
Lightning Rod
  • Can be crafted with 3 copper ingots.
  • Nearby lightning strikes within a 16 block radius get redirected to the lightning rod.
  • Gives off a redstone signal with a strength of 15 if hit by lightning.
  • Can be activated directly by throwing a trident with Channeling at it during a thunderstorm, though this does not produce a redstone signal.
Tinted Glass
  • A black variant of glass that does not let light pass through.
  • Can be crafted with 4 amethyst shards and a glass block.
    • Stained glass cannot be used to craft tinted glass.
  • Drops itself if mined without Silk Touch or even by hand, unlike glass.
  • A grayish stone that composes the outer layer of amethyst geodes.


Amethyst Shard
  • Obtained from breaking amethyst clusters.
  • The amount dropped can be increased with the Fortune enchantment.
  • Can be used to craft tinted glass, blocks of amethyst and a spyglass.
  • Crafted with 2 string and 6 rabbit hide.
  • Used to store other items (except shulker boxes) inside of it.
  • Is able to hold different types of items inside of it.
    • Holds the equivalent of one single stack of items.
      • Items with smaller stacks, such as ender pearls, take up more room in a bundle, and non-stackable items take up the whole bundle.
  • The bundle's contents can be opened by pressing use while holding it.
Copper ingot
  • Obtained by smelting copper ore.
  • Used to craft copper blocks, lightning rods and spyglasses.
  • Crafted with 2 copper ingots and an amethyst shard.
  • When used, it zooms in on wherever the player is looking, but limits their view to a small circle.
    • The overlay that limits the view can be removed with a resource pack or by pressing F1.
  • There is a unique animation for using the spyglass, which is visible in third person perspective.

World generation[]

Amethyst Geodes
  • A new feature found uncommonly underground (can rarely appear exposed to the surface close to sea level).
  • Contains blocks of amethyst and budding amethyst blocks, which are encased in a shell of calcite and tuff.
    • Also generates with a small air pocket nearby which may open into the geode.
  • Generally generates at or below sea level. (y = 63)
  • Most commonly generates at lower levels. (y = 0 to y = 40)
  • Overrides standard caves and ravines, but is overridden by abandoned mineshafts.
  • Currently has a high generation rate, presumably for testing purposes which was also done with ruined portals before.


Loot tables
  • New functions: set_banner_pattern
    • Sets tags needed for banner patterns. Parameters:
      • patterns – list of pattern objects:
        • pattern – name of pattern (square_bottom_left, bricks, etc.)
        • color – name of color (light_gray, etc.)
      • append – if true, new elements will be appended to existing ones instead of replacing
  • Added the candle_cakes block tag.
    • Contains all 17 types of candle cake.
    • If the player puts a candle on a cake, and keeps clicking the candle on the cake, the candle will be duplicated.
    • Blocks in this tag are considered candle cakes and can be lit, if they have the lit block states set to false.
  • Added the candles block and item tags.
    • Contains all 17 types of candles.
    • Blocks in this tag are considered candles and can be lit, if they have the lit, and waterlogged block states and both are false.
    • Cakes use this tag to determine if a candle item can be placed on it or not.
  • Added the cauldrons block tag.
    • Contains cauldrons, water cauldrons, and lava cauldrons.
    • This tag is used in certain pathfinding processes.
  • Added the crystal_sound_blocks block tag.
    • Contains amethyst blocks and budding amethyst.
    • Blocks in this tag play the "amethyst block chime" sound repeatedly for a short amount of time after being stepped on, gradually decreasing in volume.
  • Added the ignored_by_piglin_babies item tag.
    • Contains leather.
    • Baby piglins do not attempt to pick up items in this tag. Adult piglins are unaffected. Baby piglins still follow the other rules adult piglins follow.
      • If an item is in this tag while simultaneously being recognized as a wanted item by piglins, this tag takes precedence.
  • Added the piglin_food item tag.
    • Contains raw and cooked porkchop.
    • Piglins can eat items in this tag.
      • Eating refers to the piglin seeking out and picking up an item without appearing in its inventory, thus vanishing.



  • Can now be filled with lava.
    • Lava filled cauldrons can damage players and mobs inside of it.
    • Lava filled cauldrons give off a redstone comparator signal of strength 1.
  • Have been split into normal, water and lava cauldrons.
Grass Path
  • Renamed to "Dirt Path", as per Bedrock Edition.
    • The block ID has also been changed to dirt_path.
  • Can now be made with dirt, coarse dirt, mycelium, and podzol.
  • Particles now appear if a block is broken by a piston.
    • Sounds, however, do not.[2]
All rails
  • Are now able to be waterlogged.
  • No longer break when contacted by water.
  • Flowing water no longer breaks rails.
Shulker boxes
  • Now mimics the opening and closing of a shulker.
    • Unlike its mob counterpart, it does not elevate the player when they are standing on it.
  • Have a variation called "Candle Cake".
    • Can be created by using a candle on an uneaten cake.
    • The candle on the cake comes with 17 colors, depending on the color of the candle used to create it.
    • Pop out the original candle when any of the cake is eaten.


Firework Rockets
  • Simple firework rockets with one gunpowder can now be crafted using the recipe book.


  • If a shulker is hit by another shulker's projectile, it now has a chance of spawning a new shulker.
    • Shulkers are more likely to spawn new shulkers when there are fewer other shulkers nearby.

Non-mob entities[]

Experience Orbs
  • Now sometimes merge when in large quantities, to improve performance.
    • Merging does not affect the amount of experience gathered from collecting the merged orbs.
  • No longer follow dead players.
  • Can now move in water, but move considerably slower than they do on land.


Data and Resource Packs
  • Changed the resource pack version number from 6 to 7, as the following have been changed:
    • Drowned texture mirroring has changed.[3]
    • Slots for the game mode selector are now 26 pixels instead of 25.
  • Split the pack_version number into separate resource and data pack versions; the data pack version remains at 6.
Dedicated servers:
  • A dedicated server can enforce custom resource packs by setting require-resource-pack in server.properties. When this option is used, players will be prompted for a response and will be disconnected if they decline the required pack.
Entity storage
  • Entities have been extracted from main (terrain) chunks and are now stored in separate entities directory (similar to POI storage). Those new files are still region files with NBT.
  • The game now uses javabridge 1.1.23 instead of 1.0.22.


54 issues fixed
From released versions before 1.17
  • MC-98219 – Experience orbs follow dead players.
  • MC-108469 – Chunk-wise entity lists often don't get updated correctly (entities disappear).
  • MC-112147 – Lava burning items or XP orbs sound muted when "Friendly Creatures" slider is turned off.
  • MC-126997 – Undyed shulker box still uses cauldron's water when right clicking.
  • MC-127201/replaceitem makes quite an obnoxious sound, which is not heard by the person whose items are being replaced.
  • MC-127692 – Experience build up in furnace when using a hopper which can cause severe lag.
  • MC-130449 – Cartographer villager freezes or crashes the game when unlocking explorer maps.
  • MC-130584 – When a structure loads, water sources in the structure spread into waterloggable blocks.
  • MC-133691 – Blocks cannot be placed normally on a full cauldron.
  • MC-135552 – Dead entities are saved to chunk.
  • MC-136497 – XP orbs causing severe lag.
  • MC-141034taiga_fisher_cottage_1 is filled with water.
  • MC-143732 – Undead mobs that are halfway in sand blocks dont burn in daylight.
  • MC-151270 – Teleporting an entity from another dimension can cause UUID duplication in entity sections.
  • MC-160994 – Blocks broken by pistons do not display breaking particles.
  • MC-161592 – Entities lose their scores when switching dimensions.
  • MC-168398 – Guardian beam is darker.
  • MC-169900 – Incorrect jigsaw setting in snowy_small_house_8.
  • MC-169945 – Skeletons do not burn in minecarts while being exposed to daylight.
  • MC-170653 – Fireworks fired from a dispenser get stuck in the air when removing the block they crashed into.
  • MC-171852 – Putting item in a spectator's hand plays sound "Gear equips" for other players.
  • MC-174685 – Drowned arm texture is reversed by the model.
  • MC-175959 – One door is open in taiga_shepherds_house_1.
  • MC-177539 – When flattening a grass block into a path immediately after the grass block grows from dirt, the shovel sound doesn't play.
  • MC-177622 – One log in taiga_butcher_shop_1 seems to be misrotated - causing the side roof to look asymmetrical.
  • MC-177624 – Entrance in snowy_medium_house_2 is asymmetrical.
  • MC-181889 – Equipping sound plays when mobs picking up non-armor items.
  • MC-185357 – Removing a plant from a flower pot still plays generic armor equipping sound/shows Gear equips in subtitles.
  • MC-185359 – Using a bucket in Survival mode still plays generic armor equipping sound/shows Gear equips in subtitles.
  • MC-185360 – Milking a mooshroom for stew still plays armor equip sound/shows Gear equips subtitle.
  • MC-188044 – Using a banner on a filled cauldron plays hand animation.
  • MC-189565 – Some entities do not render inside of spawners and producing error log spam in console, potentially causing lag.
  • MC-190896 – Lag when opening a shipwreck chest containing buried treasure map.
  • MC-192594plains_stable_1 misplaced blocks.
  • MC-192629plains_stable_2 misplaced blocks.
  • MC-192876 – Misplaced trapdoor on taiga_decoration_6.
  • MC-192879 – Wall incorrectly placed on certain taiga houses.
  • MC-192930 – Zombies picking up items play the gear equipping sound and subtitle.
  • MC-193071 – Eating food items that return empty containers still play gear equipping sound.
  • MC-194685 – Collecting water from cauldrons with glass bottles in Creative mode is still inconsistent.
  • MC-194686 – Collecting water from cauldrons with buckets in Creative mode is still inconsistent.
  • MC-195125plains_animal_pen_1 misplaced block.
  • MC-195126plains_animal_pen_3 misplaced blocks.
  • MC-195351 – Comparator in compare mode can schedule unneeded tileticks.
  • MC-196542 – Small cleanup for skylight propagation code.
  • MC-196638 – Placing an armor stand logs warning "Trying to add entity with duplicated UUID".
  • MC-197009 – Referencing empty item tag in recipe can crash client.
  • MC-197140 – Jack o'lantern does not come after carved pumpkin in Creative inventory.
  • MC-197179 – Baby piglins that pick up leather do not despawn, cluttering the Nether with unnecessary baby piglins.
  • MC-197524 – Border chunks do not enforce neighbors to be loaded, causing light updates to get stuck.
  • MC-198129ReplaceBlobsFeature changed from 1.16.1 to 1.16.2, affecting Basalt Delta generation.
  • MC-198414 – If the angle in /spawnpoint is set to ±infinity, and the player dies, it will kick the player, and upon rejoin will crash the game.
  • MC-198807 – Making piglins and piglin brutes angry at certain entities (like dropped items) crashes the game.
  • MC-202246 – Drowned navigation causes memory leak/performance degredation.


Video made by slicedlime:


  1. "Minecraft Snapshot 20w45a" – Minecraft.net, November 4, 2020
  2. MC-203550
  3. MC-174685