Levels 0 through 39 in specific chunks, any light level
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 do not spawn within 24 blocks (spherical) of any player, and 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 (such as air, signs, or torches, but excluding redstone-related items) to spawn in, with an opaque block underneath. The space they spawn in must also be clear of solid obstructions and liquids. 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).
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 spawn in the normal swamp, and 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.
Slimes spawn throughout the world (except mushroom islands) below level Y=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 + (int) (xPosition * xPosition * 0x4c1906) + (int) (xPosition * 0x5ac0db) + (int) (zPosition * zPosition) * 0x4307a7L + (int) (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 is generated, and if that number is 0, the chunk can spawn slimes. To convert world coordinates to chunk coordinates, divide by 16 and round down. Note that
zPosition are 32-bit integers (ints).
The slime chunk algorithm in Bedrock Edition is different from in Java Edition. The algorithm doesn't depend on the world seed, thus the chunks slimes can naturally spawn in are the same for every world.
Slimes also drop experience points equal to their size.
Slimes move by hopping, which they do each 10 to 30 ticks (1⁄2 to 1 1⁄2 seconds), and can swim in water and climb ladders. Unlike other mobs, slimes continue moving when no players are nearby. Their exact routine is as follows:
- If no target is found, the slime waits 10 to 30 ticks (1⁄2 to 1 1⁄2 seconds). Then it changes 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 is 1⁄3 as long (3 to 10 ticks), and the slime's direction is set directly toward the target before jumping.
A slime's health is equal to its size squared, and its dimensions are 0.51 blocks times its size in each dimension. When a slime attacks, it deals damage equal to its size, except for size 1 (smallest) slimes. Small slimes do not prevent sleeping.
A slime's jump distance also depends on its size; a slime jumps 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 dies and spawns 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. This speed is noticeable when the slime has the player cornered at a wall. 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[JE only] they collide with, unlike other mobs that damage only those targets they specifically attack.
Slimes have entity data associated with them that contain various properties of the mob.
- 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 the 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.|
|Monster Hunter||Kill any hostile monster||Adventure||Kill one of these 25 mobs. Other mobs are ignored for this advancement.|
|Monsters Hunted||Kill one of every hostile monster||Monster Hunter||Kill each of these 25 mobs. Other mobs may be killed, but are ignored for the advancement.|
|Java Edition Alpha|
|v1.0.11||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 now have sound effects.|
|The slime's targeting and attacking has now been fixed.|
|Huge slimes no longer spawn naturally.|
|v1.0.13||The slime's texture has now been updated.|
|v1.0.17||Slimes now spawn in multiplayer.|
|v1.1.2||Slime spawning has now been reduced as they now appear in abundance.|
|A miscalculation in the new limit has now caused slimes to spawn only in strange locations, so natural slime spawning has now been disabled.|
|Java Edition Beta|
|1.2_01||The slime's texture has now been updated.|
|Slimes have now been returned to the game.|
|Small slimes now drop 0 - 2 slimeballs.|
|Slimes are currently very rare.|
|1.3||Slimes have now become more common.|
|1.4||A multiplayer bug has now been fixed where slimes split were visible only to the player that caused them to split and would not take any damage.  Because these slimes were client-side, the player could remove them only by exiting and logging back into the server.|
|1.5||Slimes no longer spawn in peaceful difficulty and attack only when provoked.|
|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, allowing the player to spawn slimes.|
|1.3.1||12w15a||The slime spawning rate in superflat worlds has now been decreased.|
|12w25a||The slime spawning rate in superflat worlds has now been decreased, even more.|
|1.4.2||12w38a||Slimes now 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 is quite likely that they 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||Slimes can now swim as a result of the update to the new AI.|
|Slimes now randomly change direction every so often, reducing the chance of them getting stuck in walls or corners.|
|Slimes now randomly despawn over time if no player is within a 32 block range.|
|Slimes' jumping mechanics have now been changed. The distance they are able to jump corresponds to their size; they jump approximately the same distance as the length they are. They also turn and face their whole body to the player while attacking.|
|1.11||16w32a||The entity ID for slimes has now been changed from |
|1.14||18w43a||The texture of the slime has now been changed.|
|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||Slimes now have particles when jumping.|
|Slimes now drop slimeballs.[verify]|
|0.13.0||build 3||The slime's spawning has now been improved.|
|Legacy Console Edition|
|TU1||CU1||1.0||Patch 1||Added slimes.|
|TU14||1.04||The slime spawning rate in superflat worlds has now been decreased.|
|New Nintendo 3DS Edition|
- 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 named large slime that dies produces smaller slimes with the same name.
- In Java Edition With commands, the sizes of slimes can be customized. Sizes go from 1 up to 256; the size-256 slimes the largest of any mob in the game, bigger than the ender dragon.
- Small slimes are the weakest of all mobs: they have only 1 health point, and deal no damage, despite being a hostile mob.
Slimes of various sizes underground.
Big slime covering a minecart.
Slimes as seen on a Superflat world .
A group of slimes within a village.
Slimes spawn in swamps.
- Magma Cube – a similar mob that spawns only in the Nether
- The Bedrock Edition slime chunk algorithm was reverse engineered by @protolambda and @jocopa3 and can be found on GitHub: