Place and stack spawners
Rare spawners are progression purchases. Your weekly purchase allowance starts at six and grows with Sky level, up to sixteen. Check the spawner shop for the available types, prices and remaining allowance.
Place a spawner, then right-click it with a matching spawner to add one. Sneak and right-click to add the matching stack in your hand. A block holds up to 1,024 spawners. Different mob types use separate blocks and produce independently.
One body, many mobs
Matching spawner mobs combine into a representative body. Its count is the number of mobs stored in that stack. Kill it to harvest a member; Cleave can harvest more on the same lethal hit, at most once every 0.65 seconds, the pace of a full-strength swing.
The mob you hit drops its full loot, with Looting and your Combat perks. The extra members Cleave harvests with it drop plain loot and a quarter of the combat XP, and a sweep never harvests a stack: only a direct hit does. Larger spawner stacks produce faster, and the island Spawner Output upgrade adds to their output.
AI, natural spawns and loaded chunks
You can switch off natural hostile spawns and still farm skeletons or other purchased spawner mobs. Spawner AI has its own island setting. With AI off, mobs do not wander or attack, but gravity and allowed pushes still move them.
Production needs a loaded spawner chunk and a player on the island. Empty islands do not build up offline output. Leave room for the representative body and somewhere safe to stand while farming.
Island entity limits
The default island limits are 300 physical mobs within 512 counted entities. A stack of thousands of mobs uses one physical mob slot. Check your current counts with /is entities.
At capacity, new spawns pause. Existing animals are not culled, and earned loot and XP are preserved, so drops or previously saved entities can temporarily take the count above the limit. Collect loose items and remove unused vehicles or decorations before adding more farms.