Tutorials/Wither skeleton farming
A wither skeleton farm is a mob grinder that involves creating a spawning pad inside a nether fortress, while removing all other mob spawning points nearby.
A typical farm of this type usually means destroying all platforms on which the wither skeletons can spawn and replacing them with collection points (usually lines of blocks with pressure plates on them for pistons to push into a grinding point).
You will need a variable amount of materials depending on the size of the grinder but a small sized farm needs around:
- 650 cobblestone.
- 160 redstone torches.
- 80 pressure plates.
- 80 sticky pistons.
- Several stacks of slabs, the more the better
- Note: In 1.16, the only mob that can spawn on wither roses are Wither Skeletons.
1. Begin by marking the bounds of the nether fortress chosen.
2. Destroy all of the platforms that make up the nether fortress to limit spawning.
Building the mob collectors
1. Create a line of a chosen building material (preferably cobblestone due to its common occurrence and resistance of ghast's fire balls) from one end of the marked area to the other.
2. Place pressure plates on the top of the line and redstone torches on one side of the line.
3. Place a line of cobblestone on top of the redstone torches and then place another line of redstone torches on the outward side of that line.
4. Place a third line of cobblestone on top of the second line and then place a line of sticky pistons that will push those above the first line of cobblestone.
5. Place half slabs on top of the third line of cobblestone to prevent wither skeletons from spawning on top of the collectors instead of inside them.
After the mob collectors have been made correctly and wither skeletons are being spawned, you will need to make a bucket shape of cobblestone under the collector so that all spawned mobs are at one main point. This can easily be achieved using the remaining cobblestone by making a tube from the collectors to the area chosen for grinding. Once the mobs are at the grinding point they can all be killed in one area simplifying collection and speeding up the whole process.
This design guarantees that the wither skeletons will drop their skulls 100% of the time, making for a very efficient grinder, however it requires a charged creeper. It is primarily designed for Bedrock edition but works on Java as well, however it is worth noting that only one head can be dropped per group of wither skeletons.
This does not work in versions previous to 1.13 Java, and 1.4 Bedrock due to lack of tridents.
In this method you use an iron golem to lure wither skeletons into a falling trap. This trap can be upgraded with pistons to push wither skeletons through a portal and then be blown up by a charged creeper. This is a very cheap method but only gets about 5 skulls an hour but with the modifications it can get a skull every minute. It is meant to be used as an alternative to grinding for skulls and not meant for killing the wither multiple times. This method is for all platforms but the modifications with the charged creeper is more effective on bedrock edition.
You may want to add a cage of some sort around the farm to prevent ghasts from blowing up the structure during collection. As well as that, most wither skeletons only drop coal and bones and only when they are killed by a player or a tamed wolf is a wither skeleton skull dropped.
Automatic and AFK-able designs
Using wolves, one can make an automatic wither skeleton farm by having the player stand nearby. As long as the wither skeletons cannot reach the wolves, there is no chance of the wolves dying.
This design uses slime block machines to push mobs off the spawning platforms, sort them, and grind them.
Ray's Works's Design
This design uses ghasts' enormous hit box to push mobs off the spawning platforms.
Shulkercraft's Design (Based on another of Ray's Works's Designs)
This 2020 Java 1.16.4 design uses a spawn platform in the nether with wither roses and a piglin to attract them into a drop down chute.