Tutorials/Door-based iron golem farming

Note: As of the 14w04a snapshot, valid doors are added to the closest village within range instead of the oldest one, so the village chaining mechanic discovered by Tango Tek will no longer work. This means that the Iron Trench and Iron Foundry cannot be built in 1.8, although Iron Foundries built in previous versions will continue to work.

An Iron Golem farm is an easy way to acquire many iron ingots (and less useful poppies) with minimal effort after the initial setup. It is an artificial village (or several of them, spaced far enough apart to remain separate) in which golems are spawned and then either killed immediately, or moved to a holding cell (outside the village boundary, so that new ones can spawn in their place) for later killing. If you opt for the first method, you will either need to go AFK while camping out at the collection point, have a hopper collecting your items, or else check back periodically to collect your items before they despawn. This necessity can be avoided by using the holding cell method, which allows the golems to collect while you are working nearby, and then you can harvest them all at once when you are ready so that you don't miss any drops.

General requirements
There are several ways to build an iron farm, but the most effective versions seem to be the ones that utilize two floors in the central golem-spawning zone, and keep all doors and villagers outside the zone, either above and below the center or in an outer "ring" on the same level. This is in order to maximize the number of available spaces for the golems to spawn in, which in turn will reduce the number of failed attempts, and keep the spawning rate as high as possible. This is much more effective than simply increasing the villager count to raise the golem cap, which only matters for the few seconds between the time when a golem spawns and when it is flushed out or killed, anyway. To further increase your output rate, you can build several separate "modules" and bring the golems or their drops to a central collection area. Since golems are immune to falling or drowning damage, the available killing methods are lava or suffocation (or a combination of the two, as in docm77's video.)

Odds of a missed spawn occurring: The previous section is generally true but contains an invalid assumption about the odds. There are 512 valid spawn points in the 16x16x6 block spawn area. Making a farm with only ½ of the valid spawn points (256) does not reduce your chance of spawn by ½. This is because the game randomly "tries" to find a valid place to put a golem 10 times each time an opportunity to spawn a golem comes up. So, your chances become .5 for each of the ten tries. Missing a spawn in this case is equivalent to flipping a coin ten times and have all ten come out tails. It is .5^10 or .00098 which is just about one in a thousand odds. A better suggestion would be to use some of the area of the zone to rapidly move golems out of the interference zone so they do not halt further spawning. This is a much more likely occurrence than missed spawns if the golems can’t move out of the area quickly. This is not as rare of an occurrence as has been suggested.

Design by trunkz
This design created by trunkz has an average spawn rate of one iron golem every 6 minutes. It was the first efficient iron golem farm for the release version of minecraft; most of the other farms (like JL2579's one) are based on this one. It is more resource friendly, however the spawn rate is slightly less than JL2579's farm due to the central canal/water placement.

Design by JL2579
This design created by JL2579 is very efficient, with an iron golem appearing approximately every 6 minutes. This design makes use of four iron golem spawning locations, two stacked on top of each other, and leading to a central collection point (resulting in an overall spawn every 1 1/2 minutes). The video tutorial is by docm77.

Design by Nims
This new design by NimsTV is arguably a significant improvement on the original design by JL2579. Although it does not produce any more, it is more compact, which means the water streams are much easier to configure and there is only one villager basket. If you intend to build several duplicate farms in an array, this one will be more convenient because it takes less time.

Designs by Tango Tek
These designs made by Tango Tek are by far the most space and time efficient iron farms.

The Trench compacts 32 villages inside the main building such that each village will spawn iron golems, meaning that they spawn very quickly. Iron golems will spawn an average of one every 10.6 seconds, meaning the farm will produce 1100 iron items per hour, or about a double chest of iron every 3 hours. The villages are compacted in this way using a village overlapping bug discovered by Tango that he calls "Village Chaining". A description of how this works can be found at 4:54 in the tutorial. Because the villages are so close together, they can merge if the player leaves the Overworld for more than 5 minutes or if the world is closed without the farm being built in the spawn chunks. This does not matter, however, because the farm includes an incredible amount of redstone systems that automatically rebuild all of the villages in a 20 minutes long process. You can watch the farm rebuild at 1:31:49 in the tutorial below.

WARNING: This farm uses likely one of the largest, most complex and expensive redstone systems that is still intended to be build-able in survival. Be aware of the huge amount of resources it will require compared to the other iron farm designs and only build it if you are fairly confident in your redstone knowledge and your ability to persevere through troubleshooting the farm. You have been warned.

Also note that the Iron Foundry, shown below, produces more iron, uses less resources, and is far less complex to build and troubleshoot. The only downside is that the farm below must be built in the spawnchunks, while the Trench can be built anywhere, provided it is given 20 minutes to start up each time the area is unloaded. This means that the Trench could be built on a server and be run overnight by standing inside it AFK overnight, whereas the Foundry would be built and then break as soon as the player logs out or the server is shut down. If you are building in single player or have access to the spawn chunks on your server, just build the Foundry.

The Foundry is a more recent iron farm that Tango released after discovering a simpler way to deal with the villages merging. This one increases the iron production to about 1700/hour using 44 villages instead of 32. The villages are chained together manually, meaning that the player places the doors and then breaks them himself, rather than using pistons and redstone logic. Therefore, it is much less expensive, and because of the different layout, it can have more villages and more iron produced. The build is still very time consuming but much easier to do and troubleshooting simply involves repeating the entire door placing step. The redstone consists of only a small clock and a dispenser system, and is overall much less complex and difficult to build than the Iron Trench. The villages stay loaded because an item is dispensed into a Nether Portal, meaning it travels to another dimension. This will load all the entities, including villages, in a small area around the portal for a short time. Thus, if you enter the Nether or End for more than 5 minutes (which would break the Trench) it does not matter because the villagers who see the doors keep them loaded and prevent them from being destroyed. You also do not have to refill the system that dispenses items into the Nether because the farm sorts the poppies from the iron and dispenses those into the Nether.

This design is also fairly comparable in size and building resources to some of the single village designs, so if you want to build an iron farm, this is by far the best one to use. The only significant resources required are building blocks for the structure and about 21 stacks of logs for the doors.

Tower design
This design is good especially for survival. It will get you about a stack every 2 hours. It's pretty efficient, but for faster farms, use one of the above.

Step zero - resources
To build an iron golem farm, you should have a fair amount of resources, such as cobblestone and wood, as well as a way to get villagers into it.

You will need:
 * at least 1100 cobblestone (about 18 stacks)
 * 64 doors (6 wood per door=384 wood planks or about 6 stacks.) (In 1.8 snapshots three doors are received instead of one)
 * 18 water buckets
 * 1 lava bucket
 * 4 signs
 * 2 hoppers and 2 chests (This is for the option to use hoppers to collect items when you are away from the farm)

Step one - Building location
To build the Iron Golem farm you should:


 * Choose a good location. Don't build it far from your home or main base, because you want the golems to spawn even when you are not at the farm. An ideal spot is on top of your existing home or close to it.


 * Gather the resources listed above.


 * Follow the instructions below to begin building the base.

Step two - Building instructions

 * 1.

Start by building a 4x4 cobble base.


 * 2.

Continue this until you have a tower that is 10 blocks tall. Next, break a 2x3 hole in the bottom so the golems will be able to go through.
 * 3.

Build out 7 blocks from the top of this tower to form an 18x18 platform with a 2x2 hole in the middle.
 * 4.

Build in 4 blocks from each corner, then 3 blocks diagonal in both directions to build a triangle.


 * 5.

Next build a 1 block wide platform around this so the platform is now 20x20.


 * 6.

Now build a wall with windows in it as show below. This is how wide each of the holes in the wall should be:


 * 7.

Seal off the backs of the windows, and build some small cups to hold the villagers. The cups should be 4x4 on the outside, so there is 2x2x3 of air on the inside.


 * 8.

Place doors against the back of the indents. This is to make the villagers think these are homes. it should look like this:


 * 9.

Then place down 1 water in each of the 4 villager cups, and 2 water down in between each of the raised triangles to form this pattern:


 * 10.

Place 1 water on each of the triangles in the very back corner of the wall.

Now the top part is finished, the golems will spawn once there are 3 villagers in each of the holding cups. The next step is to build the golem grinder.


 * 11.

Build 4 blocks out from the bottom of the tower and 3 blocks up on each side, then place 2 blocks at the end of it to keep the golems from escaping.


 * 12.

Next, place 4 signs in a cup shape to hold the lava that kills the golems.


 * 13.

Now place the lava in the signs.


 * 14.

Place the last 2 water in the very back of the base, so the golems will get pushed into the lava.


 * 15.

Put down 2 hoppers going into a large chest for automatic resource collection (this is not required, but it is a good idea so you don't let any of the items despawn.)