How to Spawn the Wither in Minecraft

Guide Java Bedrock

Quick answer: Build a T shape with 4 soul sand or soul soil blocks and place 3 wither skeleton skulls on top - the last block placed must be a skull. It works in any dimension. The wither has 300 HP in Java and up to 600 on Hard in Bedrock.

What you need

4 soul sand or soul soil
3 wither skeleton skulls (wither skeletons in Nether fortresses; Looting III helps)
Optional: Strength/Regeneration potions, Smite V sword or Power V bow, golden apples, milk
4 soul sand or soul soil (soul sand valleys in the Nether)
3 wither skeleton skulls (wither skeletons in Nether fortresses)
Optional: a dispenser to place the last skull from a safe distance

Step by step

Collect 4 soul sand or soul soil from the Nether (soul sand valleys are the easiest source).
Get 3 wither skeleton skulls: kill wither skeletons in Nether fortresses. The base drop chance is 2.5%; Looting III raises it to 5.5%.
Pick your arena carefully: a flat area far from your base, the classic trap under the End's exit-fountain bedrock, or a cave ceiling in the deepslate layer.
Place the T: 3 soul sand in a horizontal row with 1 more stacked on the center block (or upright, 3 high with 2 arms).
Place the 3 wither skeleton skulls on the three top blocks. The final block placed must be a skull, placed by hand or by a dispenser; pistons cannot assemble the structure for you.
Step back immediately: the wither flashes white for about 10 seconds, grows, and then detonates in a massive explosion (bigger than TNT or a charged creeper).
Fight it under cover: it fires explosive skulls that inflict Wither II (your health bar turns black and drains). In Bedrock it also dashes and spawns 3-4 wither skeletons at half health.
Kill it to get 1 nether star (always) - the key ingredient for a beacon.
The build works upright, sideways or upside-down, but the two blocks beside the base must be air, and nothing spawns on Peaceful difficulty.

Java vs Bedrock

Health differs by edition: 300 HP always in Java; 300 on Easy, 450 on Normal and 600 on Hard in Bedrock. Bedrock also gives the wither a dash attack, a half-health explosion, and it spawns wither skeletons at half health (except on Easy). In Bedrock it can be spawned by dispensers; in Java it cannot.

Versions: 1.4.2 (Pretty Scary Update)

Frequently asked questions

Can you spawn the wither in the End or Overworld?

Yes, in any dimension. The classic safe spot is under the bedrock fountain in the End, which pins it in place.

What is the drop rate for wither skeleton skulls?

2.5% base, raised by Looting to a maximum of 5.5% with Looting III (Java). Expect to kill dozens of wither skeletons per skull without Looting.

Can pistons or dispensers build the wither for you?

Pistons cannot: pushed blocks never trigger the structure. A dispenser CAN place the final skull, which is how automated wither setups work.

What does the wither drop?

Always 1 nether star (used to craft a beacon) plus 50 XP. In Bedrock, wither roses can appear where its attacks kill mobs.

Why won't my wither spawn?

Three common causes: the last block placed was not a skull, the two spaces beside the base block are not air, or you are on Peaceful difficulty. Double-check all three and it goes up instantly.

Where should I summon the wither?

Anywhere far from your builds - a remote desert, a deep cave, or a purpose-built bedrock cage under the End exit portal or on the Nether ceiling for safe farming. Never at home: the spawn explosion and skull barrage flatten everything.