Mobs in Minecraft drop all sorts of items. From materials to make blocks, to items to speed up farming, to materials for explosives, getting loot from Mobs is a big deal. And getting a lot of it is a bigger deal. Sometimes, going out in the middle of the night to kill Mobs isn’t a great plan and nobody wants to patch up a thousand Creeper holes they made trying to get gunpowder. So instead the better option might be Mob Farming.
Where to Build Mob Farms
There are two main types of Mob Farms in Minecraft and each must be built in different places. The first is the Spawner Mob Farm. This one requires you to find a Mob Spawner in your world which can be generated in Dungeons, Strongholds, and Nether Fortresses. The Spawner Mob Farm will be built around these Mob Spawners.
The other type of farm is the Natural Spawning Mob Farm. Mobs will spawn naturally in dark places and this can be used to farm them. These farms can be built anywhere but the best places to build them are in Desert biomes, as they have an increased Mob spawn rate, and as deep underground as it can be. The lower a Natural Spawning Mob Farm is in the world the more efficient it will be in spawning Mobs.
From a Spawner
Getting Mobs to spawn from your Spawner is incredibly simple. Make sure the Spawner is not near any light sources and has empty space around it. It doesn’t need blocks beneath it to spawn Mobs on, it will simply spawn them in the air if there aren’t any. Finally the Spawner only works when the player is decently close to it. You can be behind a wall or even above it but as long as you’re close it will activate and start spawning mobs.
When using a Mob Spawner, the biggest factor keeping it running is moving the Mobs away from the spawner as fast as possible. If the Spawner has Mobs near it, it will stop spawning until the Mobs leave or die.
From Natural Spawning
Since spawning Mobs naturally is more flexible, there’s a variety of ways to make places for Mobs to spawn in your farms. These places are often called ‘Spawning Platforms’ and work hand in hand with whatever mechanism you use to move the Mobs out of the farm. These platforms need to be in low light, so no torches and definitely no sunlight.
They also need a way for the Mobs to fall off them into the mechanism that transports them away. This can be done easily by making an edge to the platform and placing Signs or Trapdoors on them, which Mobs will think are solid blocks when they’re really pits.
You can also do more than just waiting for Mobs to fall. Certain Mobs will chase others, like Slimes chasing Iron Golems, Zombies chasing Villagers, and Zombie Piglins chasing players they’re angry at. Use this to your advantage by placing the Sign or Trapdoor pit between the Mobs and their target to make them walk into the pit faster.
It's also effective to use water to push them off spawning platforms but this requires a Dispenser and some good Redstone timing. It needs to be quick since the longer the water covers your Spawning Platform, the less time things can spawn there since most Mobs cannot spawn in water.
Now that you’ve got the Mobs you need to take them somewhere. Ideally you should transport them to a killing chamber nearby the player. This means transporting them far away from Spawners but still close enough for the player to activate the Spawner. Or for Natural Spawning, transporting them about 24 blocks away from the edge of the Spawning Platform.
The harder part of transporting Mobs is getting them up blocks. Mobs never listen and almost always wont willingly climb up blocks unless there’s something to chase. So this means you have to push them. Water is often the best way. Most Mobs will swim upward while in water however not all of them do.
To fix this place Soul Sand beneath a column of solid water which the Mobs will be pushed into. The Soul Sand creates a bubble column which pushes everything in the water upward and the Mobs who forgot their swimming lessons will be pushed upwards with the others.
This is the easy one. Just push them with water. But there are a few tricks to this one. Water can only flow so far and once a Mob gets pushed out it won't be moving anymore. There’s two fixes to this.
The first is to drop the floor down to continue the water stream. This is good when you have space but Natural Spawning designs wont like this since they should be built as close to bedrock as possible. This means you need a way to continue the water stream without making a hole too deep. By placing signs in a very specific way, you can have a water source floating in the air, and using this you can place a water source one block above the block beside the edge of your last water stream. The Mobs will be pushed into this next water source and keep being pushed.
Finally, if the water is too slow for you, there's a way to speed it up. By placing Ice underneath the water, Mobs will be pushed faster through it. This works with all four Ice blocks, though Frosted ice isn’t good to use, normal Ice is fast, Packed Ice is faster, and Blue Ice is the fastest.
Finally, you need to kill the mobs. This means taking all the spawned mobs to a central location so their drops can be easily collected by a player or Hopper.
Killing for Items
If you only want items from the Mobs, there's a few ways to do it. You can kill them with fall damage, almost all mobs will die after falling over 40 blocks. You can kill them with lava being dispensed. This is similar to the water before and can’t be out long since it will burn the items. The best way by far is to use entity cramming.
Entity cramming is a mechanic which only allows a certain amount of Mobs to occupy a single block space. This means by simply funneling your Mobs into a one block space, they will eventually all entity cram themselves to death.
Killing for EXP
Killing for EXP is a little harder. You want to take mobs down to as low a health as possible, this usually means making them fall just under 40 blocks, which is the most reliable method. Though you can time out the lava dispenser as well. Then you just kill the Mobs yourself. This also works if you want to use a Looting enchanted sword on the Mobs for drops.
Mob Specific Changes
Some Mobs may change how you approach the farm. For example, Endermen teleport out of water and therefore must be either pushed with Pistons or lured with an Endermite. Same with the Zombie Piglin and Blazes. Since no water is allowed in the Nether, chasing and Piston designs are required. Whereas Guardians require water to spawn.
Q. How do I make my farm faster?
A. Aside from the few tips already mentioned, there’s still a few ways to speed things up. Obviously, having more spawning space will help but also reducing other places Mobs can spawn can drastically increase your efficiency. Explore the area around your Mob Farm and place torches everywhere to make sure Mobs can't spawn in nearby caves or on the surface, making them all spawn in your farm.
Q. What Mobs should I farm?
A. It depends on what you want but the best multi purpose enemy to farm is definitely Skeletons. They’re decent for EXP and drop Bones which are useful in farming by turning them into Bonemeal.
Q. What Mobs are best for EXP?
A. The best for EXP are either Guardians or Endermen. A Guardian farm is a ton of work though since you have to basically drain the ocean so Endermen is your best bet. Making your farm in the End will make it very efficient and all you have to do is cover nearby surfaces with Carpet or water in order to stop them from teleporting.
Mob Farms are ways to kill Mobs quickly to get their drops and can be made pretty simply. You can spawn Mobs naturally or from a Spawner then all you need to do is transport them to a killing chamber where you kill them and collect their drops.