What a wither skeleton is
A wither skeleton is a tall, hostile undead mob that spawns inside nether fortresses. It looks like a scorched, blackened skeleton and stands taller than your character, close to 2.4 blocks high. Every wither skeleton carries a stone sword and starts swinging the moment it sees you.
The reason most players hunt them comes down to one rare drop: the wither skeleton skull. You need three of those skulls to summon the Wither, one of the two boss mobs in the game. That single fact turns a routine fortress mob into something worth farming.
Wither skeletons also fill out the danger of a fortress. When skeletons spawn in a fortress on Java Edition, about 80% of them are wither skeletons and only 20% are regular skeletons, so you will meet far more of the black ones than the white ones.
Where wither skeletons spawn
On both Java and Bedrock, wither skeletons spawn inside nether fortresses, on any solid block in a dark spot within the structure. They appear in groups, often two or three at once, and they mix in with blazes and regular skeletons along the walkways.
Bedrock adds a second spawn location. Wither skeletons can also appear in soul sand valley biomes, though at a lower rate than inside a fortress. On Java, the fortress is the only place you will find them.
Because they need low light to spawn, torches and other light sources cut down how many appear. If you want fewer of them while you explore, light up the walkways. If you want more of them for a skull farm, keep the spawn area dark.
How wither skeletons behave
Wither skeletons are aggressive on sight. They notice you from roughly 16 blocks away and close in fast, swinging as soon as they reach melee range. They do not use bows like regular skeletons, so the stone sword is their only weapon and they have to touch you to hurt you. Fighting from a ledge they cannot climb takes most of the threat away.
They walk in loose groups and are not careful about ledges, so they sometimes stroll straight off a walkway into lava and thin out their own numbers. One thing to remember: they will not path into a gap shorter than their height, but fresh ones keep spawning in any dark corner, so an empty-looking fortress is rarely empty for long.
The wither effect
The thing that makes a wither skeleton dangerous is not its sword damage, it is the status effect that comes with a hit. When a wither skeleton lands a blow, it gives you the Wither effect for about 10 seconds.
Wither works like poison with one important difference. Your hearts turn black, so you can still read roughly how much health you have left, and you take damage over time. Poison can never kill you on its own; it stops at half a heart. Wither does not stop. If you ignore it and the ticks keep landing, the Wither effect can drop you to zero and kill you.
Drinking milk clears the effect instantly, so a bucket of milk is worth carrying into a fortress. A golden apple or a Regeneration potion also helps you outheal the damage while it runs its course.
What wither skeletons drop
Kill a wither skeleton and you usually get some common loot, plus a small chance at the drop everyone wants.
- Coal: 0 to 1 per kill.
- Bones: 0 to 2 per kill.
- Wither skeleton skull: a rare drop, 2.5% of the time by default.
- Stone sword: an uncommon chance to drop the sword it was holding, usually damaged.
They also give 5 experience when you kill one yourself. The Looting enchantment raises the skull chance. Each level of Looting adds about one percentage point, so Looting III pushes the skull drop to roughly 5.5%. If skulls are your goal, a Looting III sword more than doubles your odds and is the single biggest thing you can do to speed up the grind.
Wither skeleton skulls and the Wither
The wither skeleton skull is the reason this mob matters late in the game. Collect three of them, then build a T shape out of four soul sand or soul soil and place the three skulls across the top. Setting the last skull spawns the Wither, a flying boss you fight for a nether star. The nether star is what you need to craft a beacon, so most players only farm skulls once they are chasing that goal.
Because the base drop rate is so low, expect to kill a lot of wither skeletons before you see three skulls. This is where Looting III and a dedicated farm pay off. You can also wear a wither skeleton skull as a helmet, though it only offers a little protection and is mostly a cosmetic choice or a way to reduce the detection range of the Wither.
How to fight a wither skeleton
A few habits make fortress fights much safer.
Their height is a weakness you can use. A wither skeleton is about 2.4 blocks tall, so it cannot fit into a space that is only 2 blocks high. If you dig a 2 block tall pocket into a fortress wall, you can hit them while they cannot follow you or reach you properly. Many corridor and nether roof farms lean on this same trick.
Carry milk to cancel the Wither effect, and bring a shield on Java to block the stone sword hits. A Smite enchantment is very strong here because wither skeletons count as undead. Smite V adds a large amount of extra damage against them and can cut a fight from several hits down to one or two.
Fire is useless against them. Wither skeletons are nether mobs, so they take no damage from fire, lava, or Fire Aspect. Skip the flame weapons and lean on raw damage and Smite instead. As undead, they are also healed by a Potion of Harming and hurt by a Potion of Healing, which is the reverse of how those potions work on you.
Building a wither skeleton farm
A skull farm is a long project but a common one for players who want a beacon or several. The usual approach is to find a nether fortress, light up everything except a large dark spawning platform, and funnel the wither skeletons that spawn there into a drop or a kill chamber.
Since these mobs only spawn within the fortress bounding box, the platform has to sit inside that region, which is why finding a fortress with a good open layout matters. Many players clear a wide area, floor it with a spawnable block, and finish the mobs by hand with a Looting III sword so every skull counts. Because skulls stay rare even with Looting, a good farm is measured in hours of running, not minutes.
Java and Bedrock differences
Most of the mob behaves the same across versions, but a couple of details differ. On Bedrock, wither skeletons can spawn in soul sand valley biomes as well as fortresses, which gives Bedrock players a second hunting ground. On Java, they only spawn in fortresses.
Bedrock also handles the sword and some combat timing a little differently, but for practical purposes the fight, the drops, and the skull recipe work the same on both. If you are farming skulls, Looting III matters on either version.
Frequently asked questions
How rare is a wither skeleton skull?
The base drop rate is 2.5%, or 1 in 40. Looting III raises it to about 5.5%. Even with the best luck enchant, you will usually kill dozens of wither skeletons before you collect the three skulls needed to summon the Wither.
Do wither skeletons burn in sunlight?
No. Unlike regular skeletons, wither skeletons do not catch fire in daylight. If one follows you through a portal into the Overworld, it will keep chasing you at noon.
Can the Wither effect kill you?
Yes. This is the key difference from poison. Poison stops at half a heart, but the Wither effect will take you all the way to zero if you let it run. Drink milk to clear it right away.
What is the fastest way to kill wither skeletons?
A sword with Smite, ideally Smite V, since they are undead. Add Looting III if you also want skulls. A shield blocks their sword hits and a bucket of milk cancels the Wither effect after a bad trade.
Can you get a wither skeleton skull with a bow?
Yes, but ranged kills do not benefit from Looting, so your skull odds stay at the base 2.5%. For skull farming, melee with a Looting sword is far better.
Where do I find wither skeletons if there is no fortress nearby?
On Java you have to locate a nether fortress, since it is the only spawn location. On Bedrock you can also search soul sand valley biomes, which sometimes produce wither skeletons without a fortress close by.
Worth the grind
Wither skeletons sit somewhere between a nuisance and a goal. Early on they are just a tough fortress mob with a nasty status effect. Once you want a beacon, they turn into the mob you build a whole farm around. Bring milk, a Smite sword, and some patience, and the skulls will come.