Tutorials/Mob farm

Mob Farms are structures built to acquire mob drops more easily and in larger numbers. They usually consist of two components, the farm itself, a large and dark room to spawn mobs and funnel them into a central location, and a Mob Grinder to kill them quickly and efficiently.

See also: Tutorials/Monster Spawner Traps, for single-species farms built around a monster spawner.

Locations
The purpose for the farm is to provide a large area that is a viable spawn position for the intended targets, and to kill the mobs quickly. Due to the rules Minecraft applies to spawning mobs, this makes the choice of a location for the mob farm a difficult topic.

Farms placed on the surface can provide good drop rates during the day, when it is one of the few spots of dark ground, but has a sharp drop in effectiveness during nighttime, when the entire surface is dark enough to support mob spawning.

Farms built underground have a time-independent drop rate, and will remain within your personal spawn range for hostiles when you go mining, but their effectiveness depends of the amount of unlit caverns in your vicinity, which provide alternative places for mobs to spawn.

Farms floating high in the sky can achieve record spawn rates in both night and day, as they represent the only viable spawn ground. However, building one in survival is rather suicidal, and due to their height they will stop working completely when you descend undergroud to mine resources. To produce loot, you have to stay at the height of the farm.

Superflat worlds will provide higher spawn rates than other worlds, as the missing air pockets underground reduce the amount of parasitic dark places.

The Nether is difficult to farm, as water evaporates and all mobs are immune to fire. This reduces the amount of functioning farm designs considerably. Lava might be used for transport instead of water, but destroys the loot. One could try to funnel the mobs trough Nether Portals to circumvent the restrictions.

Drops
What a mob farm produces depends on location and the type of grinder used to kill the mobs. Automatic killing will prevent rare drops and experience, but is safer as the player is not required to be near the mobs. Following is a table with mobs that can be effectively farmed and their usual and player-caused drops. Player caused drops, as well as experience, can only be obtained when the monster is killed manually.

Designs
When planning a mob farm, one should always consider the neccessary size, which for depends on where one plans to be in relation to the area. If you plan to be directly beneath the center of the farm, waiting for the items, the radius in which mobs would spawn can be easily used to calculate the size of the farm: floor( sqrt(1024 - (Spawn Floor Height - Collection Floor Height)^2 )) = Spawn Room Radius If you plan to spend your time in a less defined position, it might be easier to stack a simple design several times, ensuring that at least some areas are in the spawn range while limiting complexity.

Sinkhole
The easiest possible design consists of a large, empty area of simple shape, with one or more holes in the ground for the mobs to drop through. The edge of each hole has to be lined with Signs or opened Trapdoors to trick the Mob AI into believing the hole to be solid ground. With approximately 0.542 Wood per sign, they are the more economic choice over the trapdoors at 0.75 Wood each. However, Trapdoors can be controlled with Redstone, so one could shut off the farm by closing the holes remotely.

The whole room is closed by a roof to create minimal light level. A roof height of 3 allows Endermen to spawn, while a roof height of 1 would restrict the farm to spiders.

Sinkhole farms are naturally not very effective, as the chance for a mob to wander into a hole is small, and zero when the player is so far away that the mobs freeze. But they can be built quickly and cheaply and will work in the Nether as well.

Canal-Style


To improve the chances of a mob falling into the holes, one can add channels filled with flowing water, leading to the central hole. The channels are lined with signs to trick the mobs into falling in, and the water transports them into the grinders. Such a design requires a bit of planning to ensure that there is no stationary water in which the mobs might get stuck, reducing effectiveness.

Since the system uses water to transport mobs, it will fail to capture Endermen, which teleport away when touching water. Therefore, the roof of the cavern should be 2 blocks above the ground to prevent griefing of your farm by Endermen taking blocks.

Compact Canal Design


A very easily built design can be made as a 20x20 area, using eight water source blocks to fill the channels, which are exactly eight blocks long so that the water stops exactly at the edges of the central hole. The design can be easily stacked or placed next to each other to increase the effectiveness.

Minimal Canal Design


If there is not enough space for larger designs, this might be used. Its small size of 10x10 (inner area) makes it able to be incorporated into larger construction projects without trouble. It uses four water source blocks, one in each corner, with the water flowing around 3x3 squares of building material to the central hole. The parts of the water between the wall and the blocks is closed over to provide more spawning area.

Active Mob Displacement
The Canal-Style System still suffer from the mobs freezing when outside a certain range around your character. Active Systems can correct that problem, using Redstone and Dispensers filled with a Water bucket to flood the spawning grounds repeatedly, flushing all mobs into the channels to be transported to the grinders. Thus, the farm provides area for the mobs to spawn in, but does not rely on mob movement to get them into the grinder. Using this, one can omit the signs needed for the other, passive designs.

A good example of this kind of farm can be seen here, stacking the same basic design several times and using fall damage as grinder.

Other Designs
Instead of using water to transport mobs, there are various other methods to make them move towards the grinder, all of which may work better with certain mobs, but can have higher ressource requirements or lesser gathering rates.

Sky-High Mob Farm
A Sky-High Mob Farm is a structure built in a high altitude in order to generate large quanities of mob drops. This particular design is distinguished by its location far from other monster-spawnable areas. It is an enclosed box typically 20x20x6 in exterior size and varies in:

a. materials used in its construction(stone or cobblestone etc),

b. platform construction(may or may not permit spider spawnable ground),

c. number of water canals(1 or 2 depending on whether platforms permit spider spawning),

d. and internal height(permiting endermen).

The procedures for constructing an LPMC Mob Farm are outlined here:

1. Build a small pool of water 4x4 directly below where the intended opening of the farm will be. This pool has nothing to do with the finished mob farm as it is only for making constructing the farm easier. The pool will be removed when the farm is completed.

2. Pile any unessential block off one end of the pool-rim upward by placing these blocks below the player as he jumps up and continue building this pile into the air no higher than an altitude of 250 but more than 140 blocks away from any monster spawnable area. This pile will also be removed when the farm is complete, and is only for gaining access to the intended location of the finished farm.

3. At the top of this pile begin building off the sides the exit port of the farm a hole 4x4 in size. This is where the monsters will fall out of the farm.

4. From each of the four sides of this exit, build off of the sides away from the exit 8 blocks away for a total of 9 blocks including the exit rim, or 10 blocks including the exit space. These will serve as the water canals where the monsters will be directed toward the exit. These canals will be filled with water later.

5. Build platforms 9x9 between each of these canals 1 block higher than the level of the canal. The end blocks furthest away from the exit of the farm will not serve as a spawnable platform for the monsters but instead serve to support the walls that surround the structure. There should now be one platform between every two canals for a total of 4 canals and 4 platforms.

6. Before the walls and roof are constructed, the platforms should be well lit as monsters may now spawn if at any moment the player accidentally falls through the exit or builds far enough away in a corner of the roof of the farm.

7. Build a 2 block high wall around the end of the farm structure by dropping the preferred block material on top of the edges of the 9th platform end blocks.

8. After all the 2 block high walls surrounding the structure are placed, continue again building the walls 2 blocks higher than before for a total wall height of 4 blocks high. The fourth block will be used to attach the roof of the structure.

9. Begin building above this highest block with half block material of choice. The placement of the slab material must be correct in order to ensure maximum output of the farm. The slab material must be placed above a full block of any kind, this position ensures that monsters will not spawn above the mob farm. If it is placed against the side of the top of the wall, this area becomes spawnable areas for monsters which reduces the effeciency of the mob farm.

10. After all of the roof is completed, dig through the roof and fall onto one of the platforms. Cover up the roof from inside with the same slab material.

11. Fill each block end of each of the four canals with a source block of water. The player may opt to build an infinite water source on one of the platforms in order to have a place from which to fill all of these water canals before beginning to fill each canal. The inifinite water pool built on the platform should be removed before leaving the mob farm area.

12. After each water canal has 2 water source blocks placed on their respective 8th block positions, the water will flow toward the mob farm exit but will not overflow out of the exit. If this is not the case, the water source block should be stopped and the measurements should be rechecked in order to ensure that the mob farm will work correctly. If the water is not reaching the farm exit hole, the canals may have been constructed more than 8 blocks away. If the water overflows out of the farm exit, the canals may have been constructed too short or the water source block may have been placed on top of another block making its flow longer.

13. Collect all of the torches inside the completed mob farm and leave the mob farm through the exit ontop of the pile of material used to build upward initially. Dig downward 50 blocks and begin to build a platform more than 10x10 around. This will be the collection platform where the monster drops will be collected. It is important the this platform be more than 45 blocks below the farm to ensure that endermen will be killed, otherwise they will only be hurt and then have a potential of teleporting somwhere else. It is important that the platform be wide enough to ensure the player doesn't fall off the edge since falling skeletons may shoot the player causing knockback of the player.

14. A ladder may be built against the remaining pile of material for ease of access to the platform catcher, and the player may jump into the pool at ground level in order to build his ladder from ground up toward the catcher.

One-Way Doors
Relying on the random movement of mobs, One-Way Door Designs prevent the mobs from wandering backwards by using doors or pistons. Making several sets of doors can increase the speed with which the mobs move towards the hole.

The easiest configuration consists of a wall of doors (Iron on Hard difficulty to prevent Zombies from smashing them, Wood on other difficulties) with a row of pressure plates in front of them. When the mobs walk onto the trapdoors, the door opens, letting them through, but once on the other side, they can't open the door since there is no switch.

With Pistons, the arrangement is reversed, with the pressure plates on the desired side, and the pistons pointing upwards, so that they block the path of the mobs when extended. This design only work with a 2-block high roof to prevent the mobs from jumping, and even then might fail on spiders. However, it requires considerably more common ingredients than the iron door variant.

Such systems can also be used to "store" mobs after gathering them from the farm, so that they later can be killed for the rare drops and experience.

Transporting Mobs
After collecting the mobs from the farm, it might be beneficial to transport them to a different location before grinding them, so that you can access the items more easily while remaining at a close-to optimal position for the spawning of your farms.

Horizontal Transportation
Horizontal Transportation can be done easily using flowing water, with a drop of 1 block vertically for every 8 block travelled horizontally. Build a tunnel with a height of 3 blocks and a width equal to the size of your gathering holes (usually 2). Mine forward to a length of 8 Blocks, so that water placed at the start ends exactly at the drop. Repeat, but one block lower, so that the creeps fall from one funnel part to the next. Mine out the roof at the higher level for 2 or 3 more block to prevent spider clinging to the walls from clogging up the funnel.

Alternatively, one can use a cactus to grind the spiders immediately. To do this, make the first funnel part only 7 block long and place only one water source block instead of two. Place a sand block and a cactus on top on the same side as the source block. The place the cactus, you have to mine out the block next to it. To ensure the water flow on the next part, mine out the wall block next to the sand and add the water sources there and next to the sand, where there would usually be one.

Downward transportation
Transporting mobs and items downward is trivial, simply let them drop down a chute with a water brake at the bottom. Or omit the water brake when you want the mobs to die from fall damage.

Upward transportation
Upward transportation uses the fact that nearly all mobs will attempt to swim in water, moving upwards. Therefore, to get the mobs using upwards, one has to provide only a column of water with enough airholes to prevent them from drowning. This can be done by arranging signs or ladders and water source blocks in the following vertical configuration:

This can be repeated indefinitely in any direction for a mob elevator. When arriving at the right height, flowing water on top of the topmost ladder is enough to dislodge them.

However, one should remeber that Slimes do not swim, and neither do Items. These things will instead float downwards to the bottom, which can be used to separate items or slimes from other mobs.

Grinding
The last part of a mob farm is to kill the gathered mobs and collect their items. This can be done in different ways, using the variety of damage available in Minecraft, like falling, suffocating, drowing, burning, sunlight (for undead), touching cacti or simply player-applied damage from weapons.

Passive Systems do not change to kill the mobs, they rely on constantly available damage sources. The most common mob grinders, the "Lava Blade" and "Drowning Trap" fall in this category.

Active Systems have to change configuration to actually kill mobs, usually in the form of redstone devices. The most known might be the "Piston Grinder", which applies suffocation damage by pushing an opaque block into the head of the mob. While possibly faster than passive systems in killing, active systems usually have a limited capacity, and higher amounts of mobs might clog or even jam the system.

EXP farms are systems that capture and soften up the mobs, but rely on the player to deliver the killing blow, so that the rare drops and experience can be gathered. An example would be a nearly-lethal falling height which would reduce the majority of mobs to half a heart, easily killed even without a weapon. However, such systems are only as good as the player using them, and in constant danger of being destroyed by creepers if not built out of obsidian.

Video
With the upcoming Hopper, it becomes easy to collect the dropped items, even without player interference. This makes fully automatic mob farms possible where the loot will be deposited in a chest for easy accessibility.

Anleitungen/Mob-Farm Tutoriels/Exploiter les créatures Мобофермы 教程/刷怪塔