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Health points

Big: 16 (Heart.svgHeart.svgHeart.svgHeart.svgHeart.svgHeart.svgHeart.svgHeart.svg)
Medium: 4 (Heart.svgHeart.svg)
Small: 1 (Half Heart.svg)

Attack strength

Big: 3 (Heart.svgHalf Heart.svg)
Medium: 2 (Heart.svg)
Small: 0 (Empty Heart.svg)
Big: 4 (Heart.svgHeart.svg)
Medium: 2 (Heart.svg)
Small: 0 (Empty Heart.svg)
Big: 6 (Heart.svgHeart.svgHeart.svg)
Medium: 3 (Heart.svgHalf Heart.svg)
Small: 0 (Empty Heart.svg)


0.51 + Size * 0.51 Blocks
0.51 + Size * 0.51 Blocks


Levels 0 through 39 in specific chunks, any light level
swamp biome on levels 51 through 69, light level < 8

First appearances

See History

Common drops

Big: 4
Medium: 2
Small: 1

Internal ID

JE: 55
BE: 37

Entity ID


A slime is a hostile mob that spawns deep underground and in swamp biomes.


Slimes spawn in the Overworld in specific "slime chunks" below layer 40 regardless of light levels. They can also spawn in swamp biomes between layers 50 and 70 in light levels of 7 or less.

Only sizes 1, 2, and 4 spawn naturally. With use of /summon, slimes can potentially range from size 1 to 256 (NBT Size tag 0–255).

Slimes will not spawn within 24 blocks (spherical) of any player, and will despawn over time if no player is within 32 blocks and instantly if no player is within 128 blocks.

Slimes require two vertical transparent blocks[verify] (e.g., air, signs, torches) to spawn in, with an opaque block underneath. The space they spawn in must also be clear of solid obstructions and liquids.[verify] Big slimes require a 3×2½×3 space to spawn, medium slimes require a 3×2×3 space, and small slimes require a 1×2×1 space (or 1×1×1 if the upper block is not opaque).[1]

Slime size is affected by regional difficulty: chances range from 33% for each size at low difficulty to 16% small, 33% medium, and 50% big with higher difficulty.


In swamps, slimes may spawn at night between the heights of 50 and 70 provided the light level is 7 or less. They spawn most often on a full moon, and never on a new moon. Slimes only spawn in the normal swamp, not in its variant, swamp hills.

More precisely, the game checks if the light level is equal to or less than a random integer (from 0 to 7), then if the fraction of the moon that is bright is greater than a random number (from 0 to 1). If these conditions are met and the altitude is acceptable, there is a 50% chance of spawning a slime.

"Slime chunks"[edit]

Slimes spawn throughout the world (except mushroom islands) below layer 40 regardless of light level, but only in certain chunks, 1 in 10 of all chunks. These "slime chunks" are determined pseudo-randomly by combining their chunk coordinates with the seed of the world:

Random rnd = new Random(seed +
                        (long) (xPosition * xPosition * 0x4c1906) +
                        (long) (xPosition * 0x5ac0db) + 
                        (long) (zPosition * zPosition) * 0x4307a7L +
                        (long) (zPosition * 0x5f24f) ^ 0x3ad8025f);
return rnd.nextInt(10) == 0;

That is, using the chunk coordinates to help generate a seed, a random number between 0 and 9 inclusive will be generated, and if that number is 0, the chunk will be able to spawn slimes. To convert world coordinates to chunk coordinates, divide by 16 and round down. Note that xPosition and zPosition are 32 bits integers.

Bedrock Edition[edit]

The slime chunk algorithm in Bedrock Edition is different from Java Edition. The algorithm doesn't depend on the world seed, thus the chunks slimes can naturally spawn in will be the same for every world. The Bedrock Edition slime chunk algorithm was reverse engineered by @protolambda and @jocopa3 and can be found on GitHub.


Slimes drop experience points equal to their size.

If a slime's size is 1, it will also drop 0-2 slimeballs.


Slimes move by hopping, which they will do each 10 to 30 ticks (12 to 1 12 seconds), and can swim in water or climb ladders. Unlike other mobs, slimes will not stop moving when no players are nearby. Their exact routine is as follows:

The slime will search for a player (or, failing that, an iron golem) within 16 blocks (spherical) distance.

  • If no target is found, they wait 10 to 30 ticks (12 to 1 12 seconds). Then they will change direction, by a random amount up to 57.26° (1 radian) left or right, jump, and repeat the process.
  • If a target is found, the delay before jumping will be 13 as long (3 to 10 ticks), and the slime's direction will be set directly toward the target before jumping.

A slime's health is equal to their size squared, and its dimensions are 0.51 blocks times its size in each dimension. When a slime attacks, it will deal damage equal to its size, except for size 1 (smallest) slimes, which cannot do damage. Small slimes do not prevent you from sleeping.

A slime's jump distance also depends on their size; a slime will jump a distance slightly farther than its length. When landing, an amount of slime particles 1/8th its size appear.

When the player kills a slime and the slime's size is larger than 1, it will die and spawn 2-4 new slimes equivalent to its size divided by 2, rounding down.

A slime's attack speed is twice that of other melee-combat mobs. Mobs like zombies and spiders attack at a rate of one hit per second, while slimes attack at a rate of two hits per second. Slimes damage all players and iron golems they collide with, unlike other mobs that only damage targets they specifically attack.

Data values[edit]

See also: Chunk format

Slimes have entity data associated with them that contain various properties of the mob. Their entity ID is slime.

  • Entity data
    • Tags common to all entities see Template:Nbt inherit/entity/template
    • Tags common to all mobs see Template:Nbt inherit/mob/template

    •  Size: The size of the slime. Note that this value is zero-based, so 0 is the smallest slime, 1 is the next larger, etc. The sizes that spawn naturally are 0, 1, and 3.

    •  wasOnGround: 1 or 0 (true/false) - true if slime is touching the ground.


Icon Advancement In-game description Parent Actual requirements (if different) Internal ID
Adventure Adventure, exploration, and combat Kill any entity, or be killed by any entity. minecraft:adventure/root
Monster Hunter Kill any hostile monster Adventure Kill one of these 24 mobs. In 1.14,[upcoming] you can also earn this by killing one of these 2 mobs. Other mobs are ignored for this advancement. minecraft:adventure/kill_a_mob
Monsters Hunted Kill one of every hostile monster Monster Hunter Kill each of these 24 mobs. In 1.14,[upcoming] also kill each of these 2 mobs. Other mobs may be killed, but are ignored for the advancement. minecraft:adventure/kill_all_mobs



Java Edition Alpha
v1.0.11 Slime Revision 1.png Added slimes, the fifth hostile mob added to the game. There are four sizes: Small, Medium, Big, and Huge.
v1.0.12 Big slimes no longer spawn in Peaceful.
Slimes have sound effects.
Fixed slime targeting and attacking.
Huge slimes no longer spawn naturally.
v1.0.13 Slime.png Slimes have a new look.
v1.0.17 Slimes spawn in multiplayer.
v1.1.2 Slime spawning reduced as they would appear in abundance. A miscalculation in the new limit caused slimes to only spawn in strange locations, so natural slime spawning was disabled.
Java Edition Beta
1.2_01 Slimes had been reskinned and returned in Beta 1.2_01 but were still very rare. Small slimes dropped 0 - 2 slimeballs in Beta.[2] Slimes also used to be extremely rare.
1.3 Slimes became more common.
1.4 Multiplayer bug fixed where slimes split were visible only to the player that caused them to split and would not take any damage.[3] Because these slimes were client-side, the player could only remove them by exiting and logging back into the server.
1.5 Slimes no longer spawn in Peaceful difficulty and only attack with provocation.
Java Edition
1.0.0 Beta 1.9 Prerelease 5 Slimes now spawn on levels 0-39 rather than 0-16, making them much more common.
1.1 11w49a Added slime spawn egg.
1.3.1 12w15a Decreased slime spawning rate in superflat worlds.
12w25a Decreased slime spawning rate in superflat worlds even more.
1.4.2 12w38a Slimes have a new mob sound, the same as magma cubes, to make the sounds more realistic.
12w40a Slimes are now easier to find as they spawn in swamp biomes at low light level. Since slimes can't swim, it's quite likely that they will jump in deep water and eventually drown.
1.5 13w10a Slime spawn rates in swamps now depend on the current moon phase.
1.7.2 ? Huge slimes can now spawn while summoning with a command block.
1.8 14w06b Now swim as a result of the update to the new AI.
Randomly change direction every so often, reducing the chance of them getting stuck at walls or corners.
Slimes will now randomly despawn over time if no player is within a 32 block range.
Slime jumping mechanics have changed. The distance they are able to jump corresponds to their size; they will jump approximately the same distance as the length they are. They will also turn and face their whole body to the player while attacking.
1.11 16w32a Changed entity ID from Slime to slime.
Pocket Edition Alpha
0.9.0 build 1 Added slimes and slime spawn egg.
build 2 Slimes now have sounds.
Slimes now spawn naturally.
Slimes are now more common.
0.10.0 build 1 Slimes now have bouncing animations.
0.12.1 build 1 Now have particles when jumping.
Now drop slimeballs.[verify]
0.13.0 build 3 Improved slime spawning.
Legacy Console Edition
TU1 CU1 1.0 Patch 1 Added slimes.
TU14 1.04 Decreased slime spawning rate in superflat worlds.

Pre-1.4 spawning[edit]

The (pre-1.4) slime spawning algorithm is discussed in greater detail in this forum topic, but note that the algorithm has changed many times and older information may no longer be accurate.


Issues relating to "Slime" are maintained on the bug tracker. Report issues there.


  • From one large slime, the maximum experience a player can get from killing it and all the slimes that split from it is 28 experience; 4 experience from the largest, 8 experience from the 4 it splits into and 16 experience from the 4 each of those split into.
  • A slime will split into slimes of half its size, rounded down.
  • A named large slime that dies produces smaller slimes with the same name.
  • Along with armor stands, slimes are common in Adventure maps to disable interaction with items/blocks.


See also[edit]

  • Magma Cube – a similar entity that spawns only in the Nether