How to build a wither skeleton farm in Minecraft 26.3

Three wither skeleton skulls stand between you and the beacon, because summoning the Wither needs three of them, and they drop from wither skeletons at a base rate of just 2.5%. Hunting them by hand in a Nether fortress is slow and dangerous at that rate. A wither skeleton farm turns that grind into a steady, AFK supply of skulls, plus a pile of coal and bones as a bonus.

Wither skeletons are unusual: they do not spawn from a spawner block. They spawn naturally on the fortress structure itself, tied to the bounding box of the fortress pieces, at light level 0 to 7. A farm exploits that by building large dark platforms inside the fortress's structure and funneling the skeletons to one spot.

This guide targets Minecraft 26.3 Java Edition. It is a spoke of the farm guides hub, and it shares spawn fundamentals with the general mob farm guide.

What a wither skeleton farm produces

• Wither skeleton skulls, the whole reason to build it, needed to summon the Wither for a beacon.
• Coal in quantity, a renewable fuel source.
• Bones for bone meal, and 5 XP per kill (plus 1-3 more for any equipment the skeleton was wearing), same as most hostile mobs.

The skull drop rate

This is the number that decides whether a farm is worth building. A wither skeleton killed by a player (or a tamed wolf) drops a skull with a base chance of 2.5%. Looting raises it in fixed steps:

<Comparison left={{ label: "No Looting", value: "2.5% chance" }} right={{ label: "Looting III", value: "5.5% chance" }} />

• No Looting: 2.5%
• Looting I: 3.5%
• Looting II: 4.5%
• Looting III: 5.5%

That is roughly 1 skull in 40 kills unenchanted, or about 1 in 18 with Looting III. Killed by anything else, such as a dispenser-fired arrow, a fall, or splash damage, the skull does not drop at all: the kill has to come from a player or a tamed wolf. If your farm's kill mechanism is fully automatic (a dispenser trap firing arrows on a timer, for instance) it will produce coal and bones but never skulls, which defeats the point. Either finish kills yourself at the AFK spot, or route the last hit through a wolf you bring along.

How wither skeletons spawn

Unlike blazes, wither skeletons have no spawner. They spawn as part of the Nether fortress mob group, and that spawning is governed by the fortress structure specifically, not by the ordinary Nether hostile-spawn rules that apply everywhere else in the dimension:

• Spawns only occur within the bounding box of a fortress piece (a corridor, stairwell, or walkway segment). Inside that bounding box, a wither skeleton can spawn on any block; in the wider Nether it is restricted to nether brick. Walk off the fortress structure entirely and wither skeletons stop being a spawn option, no matter how dark it is.
• The light level requirement is 0 to 7, tighter than the "11 or below" rule that governs most other Nether hostile spawns. Build your platforms genuinely dark, not just dim; torch glow or lava light nearby can push the level past 7 and quietly stop spawns without an obvious symptom.
• Ordinary skeletons spawn in fortresses too, competing for the same spawn attempts, which is why the height trick below matters.

The height trick

Wither skeletons stand 2.4 blocks tall; ordinary skeletons and most other mobs are 1.95-2 blocks tall. That 0.4-block gap is small, but it is exactly enough to build a filter: put a slab, a trapdoor, or any half-block obstruction 2 blocks above the spawn platform's floor, and a wither skeleton cannot fit through the resulting gap while a regular skeleton can. Placed correctly, this biases an entire platform toward wither skeletons by physically excluding the mob you do not want, rather than relying on luck. Most working wither skeleton farms use this height restriction on every platform; it is the single most effective piece of the design, more reliable than any amount of extra platform area.

This same height rule is also why some fortress farms end up built in odd, cramped-looking spots wedged between fortress pieces: the builder is chasing headroom that is tall enough for the fortress's own structure but tuned to exactly 2 blocks at the spawn layer, not picking the location for looks.

How it works

1. Dark spawn platforms. Build large flat nether-brick platforms inside the fortress's structure bounding box, kept at light level 0 to 7, with a 2-block headroom filter (slab or trapdoor) so wither skeletons spawn but fewer ordinary skeletons do.
2. Funnel. Push or drop the skeletons to a collection point.
3. Kill. Reduce them to near-death by fall damage, then finish with a player-delivered hit (required for the skull to drop) for full drops and XP, collecting skulls, coal, and bones.

Because normal skeletons and other fortress mobs, including blazes, can also spawn in range, most designs combine the height filter with platform placement to bias spawns toward wither skeletons and away from everything else.

Building it

1. Find and map a fortress, and identify which fortress pieces you can build platforms into. Wither skeletons only spawn within a fortress piece's bounding box (any block inside it, nether brick only in the wider area), so a platform even a few blocks outside that box produces nothing.
2. Lay spawn platforms. Build wide, flat nether-brick platforms at spaced heights, all held to light level 0 to 7, each with a 2-block gap under a slab or trapdoor layer so wither skeletons fit but the filter narrows out taller obstructions.
3. Light or seal everything else nearby so caves and lava-lit caverns do not steal the mob cap, and so blazes and other fortress mobs have fewer places to spawn near your platforms.
4. Funnel to a drop. Use a sloped floor or trapdoor edge so skeletons fall into a chute; tune the fall so they land at near-death, not dead, since the finishing blow has to come from you.
5. Kill chamber and collection. Finish skeletons yourself through a one-block gap (skulls only drop on a player or wolf kill), with hoppers feeding chests below for skulls, coal, and bones.
6. AFK spot in range so spawns keep running, positioned so you can land the finishing hits.

Fortress contamination: blazes and other mobs

A Nether fortress spawns more than wither skeletons: ordinary skeletons, blazes (from their own spawners), magma cubes, and ghasts all compete for the same space. Two things make this manageable:

• The height filter is a floor, not a ceiling trick. A 2-block gap under a slab or trapdoor lets a wither skeleton (2.4 blocks tall) and an ordinary skeleton (about 2 blocks tall) both pass, but at 2 blocks exactly a wither skeleton cannot actually squeeze onto a platform that sits behind it, since it needs a touch more clearance than a normal skeleton to path in. In practice most farms use the gap the other way around: they build the spawn platform itself with only 2 blocks of clearance to the ceiling directly above it, which prevents ordinary skeletons and other taller nuisance mobs (blazes included) from wandering onto that specific platform after spawning elsewhere, while wither skeletons that spawn on the platform are already inside the space and unaffected. This keeps the platform's population cleaner over time even though it does not filter the initial spawn roll itself.
• Blazes have their own spawner separate from the general fortress spawn pool, so keeping your wither skeleton platforms away from a blaze spawner's room reduces how often blazes wander into your kill area. If one does get in, its fireballs are dangerous in the open; a walled kill chamber keeps you safe from both mob types at once.
• Ghasts spawn in open Nether air, not on the fortress structure, so sealing your platforms into an enclosed room (rather than open-air platforms) keeps them out entirely.

Common mistakes

• Lighting the platforms. Wither skeletons need light level 0 to 7, tighter than the Nether's usual "11 or below." Keep the spawn platforms genuinely dark, not just dim.
• Building outside the fortress structure. Wither skeletons only spawn within a fortress piece's bounding box; a platform outside it, even nearby, produces nothing.
• Wrong headroom. The whole point of the 2-block gap is wither skeletons' 2.4-block height; get the gap wrong and you either block them too or let ordinary skeletons through as well.
• No Looting. Skulls are already rare at 2.5%; skipping Looting throws away the jump to 5.5%, more than double the base rate.
• Automated kills only. If nothing you build ever lands the finishing hit as a player, skulls never drop, no matter how many skeletons die. Coal and bones will still come in, which can mask the problem for a while.

Rates and optimization

Wither skeleton skulls have a fixed, low base drop chance (2.5%, 5.5% with Looting III), so skulls come slowly even from a good farm, but everything else about the farm compounds in your favor:

• Looting III more than doubles the skull chance versus no enchant, this is the single most important upgrade and the only one that changes the actual drop math.
• Maximize dark nether-brick platform area within the fortress structure to increase the number of spawn attempts that land.
• Suppress competing spawns by lighting caves and, optionally, running a mob switch elsewhere so more of the mob cap goes to the fortress.
• Kill fast, with the finishing blow always coming from you, so the mob cap never stalls and every kill is eligible to drop a skull.

The wiki does not publish a mobs-per-hour figure for wither skeleton farms, since that number depends heavily on platform area and fortress layout, which vary farm to farm; treat any specific rate you see elsewhere as that builder's own result, not a guaranteed number. What is fixed and reliable is the 2.5%/5.5% drop chance itself: a steady farm gives you the three skulls for your first beacon in a realistic AFK session, and a surplus for more beacons after.

Frequently asked questions

Do wither skeletons spawn from a spawner?

No. Unlike blazes, wither skeletons spawn naturally on the Nether fortress structure, within the bounding box of a fortress piece, at light level 0 to 7. A farm builds large dark nether-brick platforms inside that structure rather than caging a spawner.

What is the exact wither skull drop rate?

2.5% base, rising to 3.5% with Looting I, 4.5% with Looting II, and 5.5% with Looting III. The skull only drops if the kill is delivered by a player or a tamed wolf; any other kill method (arrows from a dispenser, fall damage alone, and so on) produces coal and bones but never the skull.

How tall are wither skeletons, and why does it matter?

2.4 blocks, taller than an ordinary skeleton. A 2-block gap under a slab or trapdoor stops them from entering a space while shorter mobs can still pass, which is the standard trick for biasing a platform's spawns and for keeping unwanted mobs off a platform layer.

What do I need wither skeleton skulls for?

Three skulls plus soul sand summon the Wither, whose nether star crafts a beacon. Skulls are the main gate to beacons, which is why a farm is worth building despite the low drop rate.

Why are wither skeletons not spawning?

Usually the platforms are lit above level 7 (a much tighter requirement than the Nether's usual "11 or below"), built outside the fortress structure's bounding box, or the finishing hits are automated instead of player-delivered (which stops skulls specifically, not spawns). Nearby unlit caves stealing the mob cap, or a blaze spawner nearby feeding a different mob into the same space, are the other common causes.

Does Looting help with anything besides the skull?

Yes, Looting also raises coal and bone drop counts on a normal enchantment curve, but the skull chance is the reason to prioritize it here: going from 2.5% to 5.5% is the difference between roughly 1 skull per 40 kills and roughly 1 per 18.

A wither skeleton farm is the last piece before your first beacon: it supplies the skulls, and the coal and bones are a bonus. Pair it with a blaze farm for brewing and a gold farm for the rest of the Nether, and see the farm guides hub for every farm that leads to an endgame base.