Tutorials/Iron golem farming

Iron golem farming uses village mechanics to produce iron, as well as byproducts such as poppies and string. Usually, an iron golem farm is a player-constructed village in which golems are spawned and then either killed immediately or moved to a holding cell outside the village boundary for later killing. Iron golem farming is preferable to other methods of iron farming from zombies and skeletons due to a chance of iron dropping and therefore much higher quantities of iron.

Overall spawning requirements
An iron golem needs an available volume in which to spawn. There must be at least 3 transparent blocks above the spawning surface, which must be solid and flat (but not a bottom slab).

Cat cap
Villages spawn cats also, one cat for every four valid beds and one villager. The cat population is capped at 10 cats per village. Cats cannot spawn once the cat cap is reached. Because your farm starts producing cats before it's ready to produce iron golems, you must be sure that your farm kills enough cats to keep the population under 10. A few cats hanging around doesn't present a problem, but you should occasionally patrol the area for cats hiding and other places where they may go or get stuck, and kill them. If the cap is reached, cats must be killed near enough to the villagers (preferably within 16 blocks) so that the villagers are aware that the cat has died, or they don't resume causing new iron golems to spawn. Villagers won't notice the death of cats that have wandered off too far or fallen off a cliff and are still hanging around below. If the cat cap has been reached, killing cats too far away has no effect, and iron golems cannot resume spawning.

Java Edition
$$, a villager can attempt to spawn an iron golem while not having a golem alive within 16 blocks and more than 40 seconds has passed.

Spawning requirements
Iron golems attempt to spawn around a village center when the following requirements are met:
 * The village contains at least 20 beds.
 * The village contains at least 10 villagers.
 * 100% of villagers are linked to a bed.
 * 75% of villagers worked within the past day.
 * A player is within 80 blocks of the village horizontally and within 44 blocks vertically.
 * There is less than 1 naturally generated or spawned (i.e. not player-created) iron golem for every 10 villagers in the village. (The ratio of iron golems to villagers is rounded down to the nearest whole number, so to spawn a 2nd iron golem while the 1st is still alive requires 20 villagers, to spawn a 3rd requires 30 villagers, and so on.)

When these conditions are met, there is a 1/700 chance of an iron golem spawn attempt with each game tick. This averages to one spawn every 35 seconds if all the conditions are met.

On each spawn attempt, the game checks 10 random X, Y, Z coordinate in the 16 x 6 x 16 area around the village center. The spawn attempt succeeds when the following conditions are met:


 * The chosen coordinate has a solid block underneath.
 * The 2 x 4 x 2 area extending north (-Z), west (-X), and upward (+Y) from the chosen coordinate does not contain any solid blocks.

Village separation
Creating more villages increases the spawn rate. Increasing the number of beds beyond 21 results in the beds forming a new village instead of being linked to the same village. Increasing the number of villages might also result in the villagers linking to the wrong village.

Stacking villages may resolve the issue (1.13 removed Village Stacking). To prevent beds from linking to the same village, an additional 32 unclaimed beds should be placed at the original village to trigger the formation of a new village. And to prevent villagers from detecting the wrong village, make sure that they detect only the correct villages by taking advantage of their 32 blocks detection range.

Village center
A village center is the northwest bottom corner of a point-of-interest (POI) block, which can be a bed pillow or bell, or workstation and bell if there are no beds. Iron golems can spawn in a 16×6×16 volume around the village center point; that is, 8 blocks in all horizontal directions from northwest bottom corner of the POI block, and 2 blocks above the top and 3 blocks below the bottom of the POI block. However, iron golems prefer to spawn on platforms on or close to villagers' eye level.

The village center might shift if villagers lose access to their claimed beds or the population of the village changes. To prevent the village center from shifting, place water on the feet of a villager who can't access its bed.

Bugs
(apparently fixed in 1.13) reports that sometimes golems spawn stuck partway in the ground with its head visible above ground. Typically when this happens, they are spawning 2 or 3 blocks below the village center, but the ground is higher and valid as a spawn platform. Making the spawn platform 2 or 3 blocks below the village center avoids this problem.

reports that cats don't always die on magma blocks. To solve this, place carpets on top of the magma blocks.

There's also a bug where the village expands thousands of blocks from the actual village boundary. Linking the villagers to a nearby workstation can prevent the villagers from linking to workstations that are far away.

Stacking villages was never mentioned in the official changelog. Without stacking villages, villages can produce up to a maximum of 32 iron ingots/hour. See.

Legacy Console Edition
Iron golem farms in Legacy Console Edition (as well as Java and Bedrock before the Village & Pillage update) are based on doors. Iron golems spawn in a 16×6×16 volume centered on the geometric center of at least 21 doors with at least 10 villagers nearby.

Java Edition videos

 * 1.16 farm


 * 1.15.2 farm


 * 1.15 farm


 * 1.15.2 farm

Bedrock Edition videos

 * Village mechanics describing the mechanisms by which iron golems spawn in villages


 * Simple 1.14 farm


 * Future 1.16 upgrade


 * 1.16 trading hall iron farm