Village

"Villages are some of the most bustling, lively places in Minecraft outside of the player’s own constructions. They’re populated by sort-of-friendly folk involved in various useful pursuits: farmers, fisherman, fletchers, butchers, clerics, armorers and more. Including my favourite: the nitwit."

- Marsh Davies

Villages are groups of buildings inhabited by villagers or zombie villagers that generate naturally in the world.

Generation


Villages generate naturally in plains, savanna, taiga, and desert biomes. In Pocket Edition, villages may also generate in ice plains and cold taiga biomes. The type of the village, and therefore the style of all structures within it, is determined by the biome at northwest corner of the village well (defaulting to "plains" if it's not one of the other biomes).

2% of villages will generate as zombie villages. In such villages, all generated villagers are instead zombie villagers (that will not despawn, but have no special resistance to sunlight) and all doors and torches are missing.

Number and frequency of structures
The number of buildings composing a village can vary, and not every village is composed of all buildings at once. Apart from the well, which is unique and systematic, the number of buildings of each type is randomly generated, and increased in superflat worlds. Structures are picked from a weighted probability list (libraries are more common than butcher shops). There may be fewer buildings of a given type than the maximum allowed. The number of lamp posts has no restriction, as they are generated where no other buildings can be placed. Paths are found between the buildings of the village and often extend beyond them.

Paths


Village paths generate at the level of existing terrain, potentially going up steep hills or down ravines without regard for whether an entity could actually traverse the path. Paths do not go below sea level and will only replace grass (with air above), water, lava, sand, sandstone, and red sandstone; all other blocks are ignored and the blocks underneath are considered for replacement instead.

Village paths generate as grass paths where they replace grass, planks where they replace water or lava, and gravel over cobblestone where they replace sand, sandstone, and red sandstone. They are subject to the block substitutions described below, i.e. in desert villages they generate as sandstone with smooth sandstone bridges over water instead of cobblestone-and-gravel with plank bridges.

Block substitutions
Some blocks in the village structures vary depending on the village's type.

In Pocket Edition, Cold Taiga and Ice Plains villages use the Taiga substitution.

Loot


It should be noted that these rolls are not exclusive. In other words, one item can be rolled multiple times, making things like getting 10+ obsidian in a chest possible.

In Pocket Edition, blacksmith chests also include ink sacs and emeralds.

Mechanics
A village is almost always composed of at least one acceptable house and one villager. In some rare cases, villages have generated with a well and nothing else (This appears to occur very frequently on console versions). Upon creation, a village center is defined as the geometric barycenter (i.e. centroid) of the active doors' locations, and the village's size is the greater of 32 blocks or the distance to the furthest door from the center. Any villager, village golem, or siege-spawned zombie will path back into the village if they find themselves farther than "size" blocks from the center.

As the villagers move around, the area near them (a 16x16 square centered at the northwest of the block the villager is standing plus a height of 10, starting at 2 blocks aboves their head and ending 6 blocks below their feet) is occasionally checked for new valid doors ("houses"). Thus, the random movement of villagers may also slowly change the center of the village they live in, even if no houses are actually changed. If a new valid door is found more than 66 blocks outside of any existing village's center, a new village is created; if a new valid door is found fewer blocks away than that, the door is added to an existing village and the center is recalculated.

The minimum population of a village is 0.35 times the number of valid doors (see Tutorials/Village mechanics). If the population drops below that point (due to death or kidnappings), but there are at least two villagers left who can reach each other, the villagers will mate and breed until the population is above the minimum.

Adult villagers can be traded with by right-clicking/using interact button on them on PC/console. Currently, trading is not in the Pocket Edition.

Advanced village placement
When attempting to place villages as close to each other as possible (for an iron golem farm for example) if their centers are to share the same x & y or y & z coordinate then the remaining coordinate must differ by 66 or more. So for example village A at 0 64 0 and village B at 0 64 66 will not merge, but if village B is at 0 64 65 they will. For all other cases if the real distance sqrt(x2 + y2 + z2) between their centers is greater than or equal to 65 they will not merge. So if village C is built above the middle line between village A and B then their x difference is again 0 their z difference is now 33 so using the formula d2 = x2 + y2 + z2 or 652 = 02 + 332 + y2, their y difference must be at least 56 or in other words C's center should be at 0 120 33.

Note: The integer rounding in the game's internal programming may allow villages to be placed one block closer under certain circumstances, but this formula will function to keep the villages apart every time.

Popularity
A player's popularity starts at zero, and ranges between -30 and 10, and the following can alter a player's popularity: A player's popularity does not reset on death, and players cannot alter other players' popularity. Popularity changes only happen once, so if you attacked a villager, then brought him to a different village, you would get the -1 popularity in the first village, but not the second. Popularity is stored per village; a player may have a high popularity in one village and a very low one in another. When a player acts directly on a villager, particles around that villager will indicate the change in popularity. Conversely, because popularity is stored per village, if the entire village is destroyed, any accumulated popularity, positive or negative, is also eliminated.

If a player has -15 popularity or less, iron golems of that village will become aggressive to that player. If an iron golem is idle, it may become aggressive to the nearest player with -15 or lower popularity. However, "nearest" can be any distance at all, so if the village's chunks are loaded (perhaps by another player), the golems can turn hostile even after the unpopular player has traveled across the world.

If a villager dies to a non-mob, non-player source while a player is within 16 blocks, or if a monster kills a villager, then no villager in the village will mate for approximately 3 minutes.

Trivia

 * According to Jeb, originally they wanted a system for a village to expand in population if player improves it. But they found that it was computationally expensive to evaluate what constituted a house, so to make it simple, they decided that a door with an inside and outside counts as a house.
 * Farms in the villages avoid overhanging by filling in the area below them with dirt. When the farm overhangs a ravine, this can cause a very tall rectangular dirt structure.
 * Farms will generate a few blocks of open space above them if they happen to generate inside a hill. This can cause sand to float over farms in desert villages.
 * Occasionally, surface ravines will be generated through villages, causing missing pathways or even entire buildings sunken into the ravine. This also applies to cave entrances and other surface oddities.
 * In the Console Edition, in the TU19 tutorial world, the village behind the castle has a blacksmith, but there is only a Music Disc, not ordinary loot.
 * In the Pocket Edition, there are also chests in the backs of large houses in cold biomes.