Farming mobs in minecraft can be a great way to collect huge amounts of resources with little effort, besides the effort put into building the farm of course.
Most farms rely on the spawning mechanisms of mobs, though other farms use mob spawners found in dungeons and abandoned mineshafts. Hostile mobs only spawn in the dark, so we have to create a large, dark room in which they can spawn. We then also have to create a way to transport all those mobs to 1 specific point, which is where we can kill them and collect the loot.
Farms can vary greatly in size, designs and killing mechanisms, but most will have the same basic steps in common. Spawning, transporting, killing and collecting.
We first need our mobs to spawn. The way this happens will depends on the type of mob you want to farm. Hostile mobs in the Overworld will spawn in the dark, while blazes tend to spawn mostly from spawners. Other spawners are also availalbe in the Overworld, which could help you farm 1 specific mob.
To get mobs to spawn it always has to be dark, even if you use a spawner. So we start by creating a dark room, either around a spawner or somewhere on its own. Make sure to light up the room while you’re building, or play in peacul mode to prevent monsters from spawning and attacking you.
The size of the room doesn’t matter too much, but remember that mobs will only spawn and stay spawned if they’re within 128 blocks of the player, so keep this in mind when deciding how big and, more importantly, how far from your base you’re going to build.
You can also restrict the height, but it has to be at least 2 blocks for any mobs to spawn, including spiders. Endermen will only spawn if the room is at least 3 blocks heigh, so you could potentially filter those out by making the room only 2 blocks high.
It’s possible to create multiple layers, which could allow you to farm many more types of mobs in 1 area. But note that passive mobs rarely spawn after the chunk you’re in has been generated, so it’s hardly worth it to create such spawning room for passive mobs. Breeding is much easier and faster.
Once you’ve made the spawning room, it’s time to create a transportation system. Again, this will hugely depend on the type of farm you’re creating and the size of your farn. Mobs will only wander around if the player is within 32 blocks of that monster, if the player is any further, the mob will simply stand in place, though it can be moved by pistons, water and other methods.
The transportation systems will allow us to collect all the mobs in 1 single place, where they can either be killed by the player or by an automated system.
Most people use a system of canals to transport the mobs to a central point in the middle. This is the easiest method and doesn’t require a lot of planning, though there are a few things to keep in mind.
Water will flow up to 8 blocks from it’s source, so the canals will have to be lowered every 8th block to make sure the water will continue to flow. This is generally not too much of an issue, especially if you create straight canals, but it’s something to keep in mind.
Mobs will also float in water, so you might want to plan the part where your canals meet first. While mobs will generally flow with the water current, mobs will often get stuck if they have to go through a single hole in the floor leading to the collection part of our trap. So make sure the mobs can fall down by either creating bigger holes or by preventing the water from flowing into that hole, either by placing signs on the sides of the hole or by making sure the water has to flow 9 blocks to reach it.
Also note that some mobs, like skeletons and zombies, have an AI system which prevents them from walking off the sides of blocks if the fall is too deep. This means they might not fall into your canal, which is the hole point of this transportation system. To counter this, place signs on the edges of the canals, without blocking the water. The mobs consider signs as blocks they can walk on, so they’ll try to walk across them, but they will instead fall into the canals. But don’t worry too much about it, as long as the fall isn’t higher than 2 blocks, the mobs will fall down.
As mentioned, mobs will not move when you’re too far away from them, so they will not walk into the canals. This means we have to find a different solution for those cases.
Waterfalls offer such a solution. By creating togglable waterfalls using pistons, we can poor water on the platforms with mobs, which will push them into the canals, or any other transportation system you’ve made.
Creating this system isn’t too difficult, all you do is connect a bunch of pistons to a single lever with redstone, though depending on the size of your farm, this system could become huge. But even huge systems aren’t too difficult to make. Make sure to test your system by placing a few torches on every platform where water has to fall, all the torches should be flushed away after you’ve tested your system, as torches break when water flows against it.
Once we’ve collected all the mobs in 1 place, it’s time to kill them. This can be done in various ways, but it’s important to note that some items can only drop if the monsters are killed by the player, like spider eggs.
No matter the system you choose, you’ll always have to collect the loot, which can either be done by walking to this collection point or by creating another (water) transportation system which takes your loot directly to your house.
Killing the mobs yourself is easy, but it can take quite a long time, especially if there are a lot of mobs. This means it’s a lot easier to hurt the mobs in some other way before you have to hit them. The easiest way to do this is by dropping them from a height.
By making the mobs fall from a height you can control the amount of health they’ll have left. Fall damage is done when a mob falls more than 3 blocks down. Every block length beyond those 3 blocks will cause half a heart of damage, so a skeleton would have to fall 22 blocks to be left with half a heart of health, which means it can then be killed with your fists.
This is also very useful to save on weapon durability. If you’ve built your farm in such a way you can’t make them fall, try adding a water elevator to make the mobs float up, before then dropping them down again. This is created by placing signs and blocks of water in a 2×2 grid. Make sure the signs and water blocks are placed diagonally and alternate as you go up.
You could also harm the mobs in other ways, like cacti, lava or arrow firing dispensers. But all of these could potentially kill the mob, which isn’t what we’re after in a manual setup, as this means we don’t get the special drops.
This is also the only way to get experience orbs, which is another reason why the fall and punch system works best.
There are numerous ways to kill the mobs automatically, without destroying the drops. Some will work better than others, though all of them are quite easy to build.
Fall damage is one of the best ways, as it’s quite easy to set up and you can quite easily calculate how high you have to build for a specific mob to die.
This is also a perfect way to ensure all drops reach you, as some methods could destroy part of the drops.
Lava is probably one of the fastest ways, as it deals the most damage. You can make the mobs get stuck in lava with their faces by making them flow into stairs, which hold the lava up above the water and collection part. The mobs will be forced into the ladder by the water, which means they’ll climb the ladder into the lava and die. The drops will fall into the water, which will then transport it to your collection point.
Note that lava could potentially destroy some of the drops, though it’s generally not much of an issue, as more mobs will come and die to drop their loot.
Cacti can also be used, but they’re often more destructive towards the drops than lava is.
They also have the disadvantage of having to be placed on sand, which can then prevent some items from dropping into water or any other collection system you’ve made.
Pistons are a good alternative to kill monsters without losing any of the drops. By crushing the mobs with blocks on pistons, the mobs will get stuck in those blocks and suffocate, the drops can then be transported or picked up. Note that mobs will not suffocate if they get stuck in a piston arm, so make sure the piston arm is pushing a block, rather than using the piston arm itself to do the crushing.
Daylight can be used to kill skeletons and zombies, though this means you can only kill them during the day and you have to transport them to a part that’s outside. You will also be unable to kill other mobs with this, so they could plug the collection area.
It’s important to know mobs will not spawn beyond a height of 128, so don’t bother building anything beyond that level.
You can filter some of the mobs that are collected by making different sized holes. Spiders can fit through 1 block high gaps, which means they can be taken out seperately. Zombies and skeletons will die in daylight, so by making your farm transport the mobs through a part that is exposed to daylight, skeletons and zombies can be killed, while leaving the creepers and other other mob you didn’t filter. This is a great way to farm a large amount of creepers, as you can filter out spider as well, because they don’t fit through 1 block wide gaps.
Note that there’s a cap on how many mobs can spawn, which depends on the amount of chunks are available for spawning. In single player the cap is 79 for hostile mobs, but this can be higher in multiplayer servers if the players are spread out. This means it’s best to kill all the mobs you chose not to collect, as they will take up potential spawning spots.
If you want to farm endermen, make sure to build your farm out of blocks they cannot pick up, like slabs. Otherwise you risk a defective farm when an enderman picks up the wrong block.