| Mob cap | A category stops spawning when its mob count reaches cap x chunks in range / 289. Chunks in range are all chunks within 8 chunks of any player, so one player alone gives exactly the cap from the table. |
| Cap per player | Each player also has a personal count per category. A chunk only spawns a category if at least one nearby player is below the cap for it. |
| Not counted | Mobs that cannot despawn (named, tamed or otherwise kept) do not count toward the cap. |
| How often | Every game tick each chunk in range tries one random position per category. Animals (the Creature category) only try once every 400 ticks (20 seconds). |
| Distance from players | Mobs never spawn within 24 blocks of a player or within 24 blocks of the world spawn point. The chunk center must be within 128 blocks of a player. |
| Pack | One try makes up to 3 packs. Each mob in a pack is placed up to 5 blocks from the last one on each horizontal axis. A try stops after 4 mobs: 8 for Wolves and most fish, 6 for Horses, Donkeys and Llamas, 5 for Salmon, 1 for Ghasts and Pillagers. |
| Despawn at once | A mob that can despawn is removed at once when the nearest player is more than 128 blocks away (64 blocks for fish). |
| Random despawn | Farther than 32 blocks from the nearest player, after 30 seconds without a player within 32 blocks, a mob has a 1 in 800 chance each tick to be removed. |
| Mobs that stay | Animals, Villagers, Wandering Traders, golems, Allays and the Warden do not despawn by distance. Untamed Cats and untrusting Ocelots can despawn after 2 minutes. Fish and Axolotls despawn unless they came from a bucket or have a name. Raiders stay while their raid runs. |
| Hostile mobs, Overworld | Block light must be 0. Sky light blocks the spawn with a chance of sky light / 32. Then the light level, with sky light lowered by night and weather, must be at most a random number from 0 to 7. In a thunderstorm sky light counts as 10 lower. |
| Hostile mobs, Nether | Light level 7 or lower. There is no separate block light limit. |
| Hostile mobs, End | Block light must be 0. |
| Animals | Most animals need a Grass Block below and light level 9 or higher. Animals also spawn with new chunks when the world is generated. |
| Peaceful | Hostile mobs do not spawn on Peaceful. |
| Slime chunks | 1 chunk in 10 is a slime chunk, fixed by the world seed. Below Y 40 a Slime spawn there succeeds 1 time in 10, at any light level. |
| Swamp Slimes by moon | In Swamp and Mangrove Swamp, from Y 51 to 69, the chance is 50% at full moon, 37.5%, 25%, 12.5% and 0% at new moon, and the light level must be at most a random number from 0 to 7. |
| Phantoms | Checked every 60 to 119 seconds at night for each player at sea level or higher with open sky. A player needs more than 72,000 ticks (60 minutes, 3 game days) since the last rest. The chance is (ticks since rest - 72,000) / ticks since rest. They appear 20 to 34 blocks above the player. |
| Wandering Trader | Every 20 minutes the game rolls a chance that starts at 26% and rises to 51% and 76% after failed rolls. A passed roll then has a 1 in 10 chance to spawn the trader within 48 blocks of a player or a nearby village bell. It comes with 2 Trader Llamas and leaves after 40 minutes. |
| Pillager patrols | From world time 120,000 ticks (after 5 game days). Every 10 to 11 minutes in daylight there is a 1 in 5 chance for one random player, not close to a village. The patrol appears 24 to 47 blocks away on each axis, at block light 8 or lower. Size is regional difficulty rounded up, plus 1. None in Mushroom Fields. |
| Zombie sieges | At midnight there is a 1 in 10 chance of a siege that night. It needs a player inside a village, not in Mushroom Fields. 20 Zombies spawn about 32 blocks from the player, one every 3 ticks, following the normal hostile light rules. |
| Monster Spawner | Works while a player is within 16 blocks. Every 10 to 40 seconds it tries 4 mobs within 4 blocks horizontally and 1 block up or down. It waits if 6 or more of the same mob are inside the 9 x 9 x 9 block area around it. Hostile mobs still need darkness, but not a solid block below. |
| Trial Spawner | Activates for players within 14 blocks and ignores light. Default: 6 mobs in total plus 2 per extra player, 2 at a time plus 1 per extra player, one spawn every 2 seconds within 4 blocks, then a 30 minute cooldown. Trial Chambers spawners mostly use 3 at a time and 1 second between spawns. |
| Game rules | Separate game rules switch mob spawning, monster spawning, patrols, Phantoms, Wandering Traders and spawner blocks on or off. |
