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Minecraft 18w15a
Java Edition 18w15a.png

Java Edition



Release date

April 11, 2018

Snapshot for



Client (.json)

Protocol version


Data version


18w15a[1] is the thirty-first snapshot released for Java Edition 1.13, which adds most of the features from Bedrock Edition beta dolphins, blue ice, conduits, and icebergs.



Blue ice
  • Crafted using 1 heart of the sea and 8 nautilus shells.
  • Can be activated by placing prismarine, prismarine bricks and/or sea lanterns in 5x5 open squares around it.
    • When active, will affect nearby players in water or rain with the Conduit Power status effect.
  • A complete structure will fully power the conduit.
    • Emits a strong glow, at light level 15.


Heart of the sea
  • Used to craft conduits.
  • Not available currently in survival.
Nautilus shell
  • Used to craft conduits.
  • Can be obtained by fishing.
  • Drowned can spawn holding a nautilus shell.


  • Spawn in all oceans except frozen.
  • Are neutral. Like wolves and zombie pigmen, dolphins will attack in groups if one is angered.
  • Can be fed using raw cod, but they do not breed.
  • Sometimes drop cod on death.
  • Play with nearby items by picking them up and dropping them after a short moment.
  • Occasionally jump out of water.
  • Can also jump between disconnected bodies of water.
  • Chase after boats and jump over water surfaces.
  • Suffocate after spending too much time on land.

World generation[]

  • Generate in frozen oceans.


Conduit Power
  • Given when a conduit is activated.
  • Stops the breath meter from running out, gives underwater night vision and increases mining speed.
  • When active at full power, the range will increase and hostile mobs within 8 blocks will take damage.


  • Added "Biome Blend" distance video option.



  • Has a new texture.
  • Now only blocks 1 light per block, instead of 3.
    • This only affects newly placed water.
  • Underwater vision from previous snapshots is gone; water is darker at lower depths.
  • Ocean variants have their own water colors, and the swamp water color has been changed.
  • In newly generated chunks, it is less likely to find frozen oceans next to warm oceans, etc. It is, however still possible to find warm oceans next to snowy tundra, etc.


  • Mobs can now spawn on top of ice.


  • It is now possible to swim through one block holes again.
  • The transition between swimming and normal state is now smoother.
  • Sprinting at the surface of water no longer makes the player swim; instead they stay at the same altitude constantly.


  • Optimized fog rendering.
  • Added "Thanks for the fish!".


32 issues fixed
From released versions before 1.13
  • MC-25866 – Splash Potion of Saturation has no effect
  • MC-63714 – Zombie Pigmen get angry when hit in creative
  • MC-98123 – Saturation with an AreaEffectCloud
  • MC-112389 – Saturation Potions no longer work in 1.11
  • MC-121889 – Animated Texture Interpolate causing crashes
  • MC-121891 – Animated texture ignoring frames acting non-iteratively
From the 1.13 development versions
  • MC-121479 – Clicking on world, save and quit to title and quit buttons freeze the game for a second
  • MC-122354 – Flying with elytra crash game / kicks player
  • MC-123055 – Villagers not breeding, recognizing houses or farming
  • MC-123585 – Closing world while debug pie chart is open causes crash
  • MC-123853 – Mobs don't burn when standing in double plants/cobweb
  • MC-124906 – Underground lava and water lakes and mob spawners generate with air instead of Cave air (cave_air)
  • MC-124918 – Biome-specific structures generate at wrong biomes in superflat
  • MC-124953 – Vines generate beneath jungle at y-level 64
  • MC-125083 – New world generator doesn't generate snow on trees in snow biomes
  • MC-125106 – Liquids in generated structures don't update
  • MC-125140 – Dungeons do not use cave_air
  • MC-125188 – Releasing the sprint button will no longer stop sprinting until you touch the ground
  • MC-125195 – Spectator mode will still allow the swimming animations
  • MC-125219 – Logs do not retain their rotation when stripping them
  • MC-125240 – Player is unable to swim through one-high water with a solid block above
  • MC-125478 – Underwater plants don't survive directly under ice
  • MC-125530 – Swimming while touching ground shakes viewport if View Bobbing is enabled
  • MC-125578 – Splash turtle potions missing "splash" in translation
  • MC-125579 – Tipped turtle potion arrows inconsistently capitalize "The"
  • MC-125698 – The player can swim in 1 block high water
  • MC-126087 – In creative mode, fish buckets are used when placing the fish
  • MC-126097 – Will not drop the grilled fish, when cod and salmon are burned to death
  • MC-126185 – Fish unrestricted spawning causing world to inevitably crash from the number of entities
  • MC-126269 – The player can see underwater even with no light sources
  • MC-126557 – Sea grass, kelp and coral can be generated on magma blocks
  • MC-127276 – Zombie transform to Drowned in less than waist-high water


Video made by slicedlime:


  1. "Minecraft Snapshot 18w15a" – Minecraft.net, April 11, 2018