Mob Stacking

A stack of 130 cows.

Mob stacking is the server's behavior of grouping multiple mobs into a single entity in order to prevent server lag. Mob stacking is used primarily on the Skyblock and Main Network servers.

Mob Stacking Behavior(top)

Stacking Radius and Limits(top)

Stacking occurs when a group of at least five mobs are within a 15 block radius in each horizontal direction as well as a 10 block radius above and below from a central mob. The server checks for mobs to add to stacks every five seconds.

When two stacks are within the stacking radius of each other, the stack with the higher number of mobs in the stack is prioritized over the stack with the lower number of mobs. The number of mobs in a stack has an upper limit of 500 on the Main servers and 25000 on Skyblock.

Stacking and Mob Traits(top)

Mob stacking considers several unique features of mobs before placing them into mob stacks. Villagers of differing professions/robe colors, sheep that are sheared or not, whether or not the mob is a baby mob, and mob color (llamas, wolves, parrot, and sheep).
The following traits should cause mobs to stack together with similar traits.
On the Main Server the following mobs will stack by variant/color.

• Frogs
• Sheep
• Horse
• Llama
• Parrot
• Cat
• Mooshroom
• Fox

Other stacking traits:

• Sheep will split from a stack when sheared.
• Bees will stack with other bees that have pollen and/or nectar.
• Turtles will not stack if they are expecting eggs.
• Baby mobs will stack with other baby mobs of its type. (Baby Zombie stacks with Baby Zombie).
• Allays will not stack with other allays if it has an owner.

Using a nametag on any stacked mob will split it from its stack and it becomes un-stackable. If your mob disappears even when nametagged please check into your town settings and ensure your mob is completely protected from other players killing or any other accidental death.

Skyblock and Mob Challenges(top)

On the Skyblock Server, mob stacks will only act as one mob (and not the amount in the stack) when being used toward challenges that require the player to be within range of several of one type of mob. In order to accomplish these challenges, players will need to be within range of the mobs before they have stacked or will need to nickname them with Name Tags in order to separate them.

Killing Mobs in Mob Stacks(top)

Each time a mob is killed by a player bow/melee attack or sweep attack, 1-5 mobs are killed in the stack. The experience points gained from killing one of the mobs is multiplied by the number of mobs that are ‘killed’ from the stack.

If a mob stack is killed by fall damage, all mobs in the stack are killed. Any other means of mobs being killed (e.g. explosion, lava and fire, etc.) will cause only one mob to be killed. Mobs that only drop items after being killed by a player will retain this behavior if killed by non-player means.