Stacking puts several spawners of the same mob into one block. The stack produces more mobs and more virtual loot in proportion to its size. A single placed spawner can hold up to 64 spawners.
Adding to a stack#
Place a spawner item against a placed spawner of the same mob type, as you would place a block on its side. The item joins the stack, and the stack count goes up by the number of spawners the item holds (one for a newly bought spawner). This works on any placed spawner of that mob, including another player's: the spawners you add become part of that stack.
What happens depends on the upgrades each side carries:
| Situation | Result |
|---|---|
| The item and the stack have the same mode and the same upgrades | It merges for free. |
| The stack has speed, amount, drop chance or virtual production levels the item does not, for example a newly bought spawner on an upgraded stack | A confirmation menu shows a price. Pay it to add the spawner. If the stack only has extra storage or XP levels, it merges for free. |
| The item has upgrade levels the stack does not | Refused: "Those spawners cannot be stacked together; their type, mode or upgrades do not match." |
| A different mob | Refused with the same message. |
| The stack already has 64 | Refused: "That spawner stack cannot hold any more." |
If the spawner was removed while you were stacking, you see "That spawner is no longer registered." If the merge fails for another reason you get the item back, with "That spawner could not be added to the stack. Please try again."
Topping up an upgraded stack#
Upgrades belong to the placed stack and apply to every spawner in it. A spawner you add pays for the levels the stack has and it does not.
The Add Spawners To Stack menu shows:
- the number of spawners you are adding and the stack size before and after,
- the upgrades they are being brought up to, and
- the total price. It is charged per spawner added.
Click Confirm to pay and merge, or Cancel to keep your item. If you cannot afford it, nothing is charged.
The price of a level is its normal upgrade price for one spawner. Speed, amount, drop chance and virtual production are charged for every spawner you add. Storage and XP capacity are never charged, because they are one shared buffer for the whole stack. See Spawner Upgrades for the prices.
Splitting a stack#
Open the panel and use the withdraw buttons. Only the owner of a spawner (or anyone for an ownerless one) can split it.
| Button | Withdraws |
|---|---|
| Withdraw 1 | One spawner |
| Withdraw half | Half the stack, rounded down, at least 1 |
| Withdraw custom amount | A number you type when asked "Enter the number of spawners to withdraw" |
| Withdraw all | The whole stack. The placed spawner is removed. |
If the number is outside 1 to the stack size you see "Choose an amount between 1 and <stack>."
What the withdrawn spawners keep:
- Partial withdrawal: speed, amount, drop chance and virtual production upgrades that were bought per spawner go with the withdrawn spawners. Storage and XP capacity stay with the placed stack, and the withdrawn item carries no stored items or XP. Withdrawn spawners come back in physical mode, and you can switch them to virtual again once placed.
- Withdraw all: the item carries everything the stack owned, including stored items and XP.
If a split cannot be handed to you, for example because you logged out, it is reversed, and if that is not possible the item drops at the spawner.
Stack limits#
A stack of 64 is the cap. Place a second spawner block of the same mob nearby to go beyond that, and remember that each placed block counts towards your 100 spawner limit. See Obtaining Spawners.