Farming & XP
How to Build an XP Farm
Wrap a dungeon spawner in a dark room, funnel the mobs with water, drop them 23 blocks to one heart and one-tap them at an AFK slot. Banked from level 0 to 30 in about twelve minutes.
The 23-block rule
- 1Light-proof the spawner roomWall and roof a 9x9x4 box of cobble/deepslate around a dungeon spawner so the inside stays at light level 0. Mobs spawn on the floor; nothing else can spawn nearby.
- 2Cut the water channelsPlace water source blocks in the corners so the flow pushes mobs toward one center hole. Leave a single open block as the drop so they all funnel into it.
- 3Build the 23-block dropDrop hostile mobs exactly 22-23 blocks: enough to leave them at half a heart, not enough to kill them. You want the XP, so they must die to your hit, not the fall.
- 4Make the 1-hit kill slotLand mobs in a glass/iron-bars chamber with a one-block gap at your eye level. A single un-enchanted hit finishes a 1-HP mob and drops the full XP to you.
- 5Set the AFK spotStand on the plank platform in the kill gap and hold attack. Hoppers under the chamber collect drops while you bank ~38 levels per hour.
What you need
Cobble / deepslate walls
Water for channels
Hoppers for drops
Any sword to finish
Quick answers
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How fast is a spawner XP farm?
A single dungeon spawner pushes roughly 35-40 levels per hour once you AFK at the kill slot. That is about 0 to 30 in 12 minutes, far faster than mining.
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What fall distance leaves a mob at 1 HP?
22-23 blocks. Zombies and skeletons have 20 HP; a 23-block fall deals ~21 damage minus the first-block grace, leaving them on half a heart for a free one-tap.
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Do I need a sword enchant?
No. The drop already leaves mobs at 1 HP, so a bare wooden or stone sword one-shots them. Use Looting III only if you want more drops, never for the kill itself.
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Why is my spawner not spawning?
Light is leaking in. Spawners need light level 0 and a player within 16 blocks. Re-check the roof and walls, remove any torches, and stand on the AFK platform.
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Single spawner or a double?
One spawner is plenty for fast XP. Linking two dungeon spawners into one drop column roughly doubles the rate but needs the rooms within 16 blocks of your AFK spot.
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Can mobs path out of the water?
If they wander, your channels are short. Every floor tile except the center drop should be flowing water so the current always carries them to the hole.