Swamp

Half of the swamp is water you walk into without noticing: shallow pools between oak trees trailing vines, lily pads on the surface, clay and mud underfoot. Blue orchids grow here and in no other biome.

At night slimes come out in the open instead of staying deep underground, which is what makes this the biome to farm slimeballs in, and swamp huts stand on their stilts with a witch and a black cat inside. Two smaller things follow from all that damp: fire burns itself out faster than it does elsewhere, and a map drawn here comes out looking like open water.

Temperature 0.8 against 0.9 humidity is a humid, mild climate: rainfall, never snow, which is what the temperate group does. The neighbouring biomes decide where the outline ends, so every seed lays it out differently. minecraft:swamp is common, has been in the game since Beta 1.8, and 1.21 still generates it.

Low, wet Overworld ground. River, Mangrove Swamp, Plains and Jungle border it, and the water starts before you notice you are standing in it.

Look for flat, murky shallow water dotted with lily pads and vine-draped oak trees at low elevation.

Common, and following a river downhill is the surest route to one. Slimes come out on the flats after dark, bogged shoot from the shallows, and a swamp hut on its stilts is the one thing built here. It belongs to the Overworld and does not appear in the other two dimensions. Being low ground, it will reveal itself soon after you travel downhill: follow an ordinary river long enough and the bank turns to mud on its own, which is nearly always how people reach one. There is no hunting involved, since those usual neighbours run through it.

Frogs are the animal here, on a fifth of every spawn attempt, two to five at a time. A frog eats small slimes and magma cubes, and the variant it grows into, cold, temperate or warm, is set by the biome it grew up in rather than by its parents.

The other two are not friendly. Bogged, about 1 in 17, is the mossy skeleton that fires poison-tipped arrows, and it comes in fours. Slime is rarer on paper at roughly 1 in 500, but this is one of the few places where slimes spawn out in the open instead of deep underground, and a slime splits into smaller copies when killed, each of them dropping slimeballs for sticky pistons and leads.

What makes the swamp special is the witch. She lives in the hut rather than spawning across the biome, throws harmful splash potions and drinks beneficial ones to heal, and she is the reason this is the biome to visit if finding one is the plan one. Harmless company is thin on the ground here, so watch the water instead: behind the frog, for example, the numbers put bogged at 1 in 17 per attempt.

Slime

Frog

Bogged

Start with the water: Clay sits in the shallow bed in whole pockets, so a swamp is the cheapest bricks and terracotta you will ever fire, and Mud comes out of the same floor for packed mud and mud bricks. Lily Pad floats over both, Vine hangs off the oaks, and Blue Orchid grows here and nowhere else in the world.

Above the waterline the harvest is wood from its trees, flowers for dyes and the sugar cane along the banks. Bone Block and Lily Pad are both blocks that only a couple of biomes grow, which makes the swamp a strange mix of common mud and things you cannot pick up anywhere else.

Seven separate plantings share this ground: the trees, the flowers, sugar cane at the edge, brown and red mushrooms in the shade, and the firefly bushes that turn up both at the water and away from it. That is why no two swamps look alike from the air.

One thing to know before you build here: fire burns itself out faster than it does elsewhere, so a lightning strike in a swamp rarely takes the whole wood with it.

In terms of mining, clay is plentiful in the shallow bed and worth knowing about before you fire a single brick anywhere else.

Blue Orchid is the only blue flower that grows in this water, and the clay under it is what you carry home: a blue orchid on a clay bank is the swamp in one picture.

A Vine hanging off an oak into the water is the ladder the swamp builds for you.

Lily Pad

Vine

Blue Orchid

Clay

Mud

One hut, one witch, one biome. The swamp hut stands on stilts over the shallow water with a witch inside and a black cat on the floor, and swamp is the only biome on this site where that hut generates. That makes it the reason most people come looking, since the witch keeps brewing regardless of what you think of the arrangement.

Nothing else is tied to the biome. The lily pads, the vines hanging off the oaks and the clay under the water are the rest of what you get above ground, while mineshaft tunnels run under the water table and dungeon rooms sit beside them without caring which biome they ended up under, with a stronghold among them if the world put one close. A hut inhabited by its witch is among the main reasons for seeking a swamp out, and finding one is quick: seek the still water and the hut follows.

Fifty two passes, tied for the longest list in the Overworld. Two trees per chunk with a third on one chunk in ten, sugar cane on one chunk in three, firefly bushes on one in eight, red mushrooms on one in 64, water lilies in patches of 4 and 10, and fossils under one chunk in 64. Seven of those passes belong to the swamp alone, which is more than any other surface biome runs.

A tadpole that grows up in this water becomes the ordinary temperate frog, because the swamp is on neither the warm nor the cold frog list. That makes it the only frog biome on this site with no classification at all.

Slimes are allowed to spawn on the surface here rather than only deep underground, which is the rule that turns a swamp night into a slimeball farm.

The swamp is also one of the thirteen biomes that draw their water outline on a map, so the edge of it is visible before you walk it.

The swamp hut is the smallest structure with the biggest rule attached: it forces its own spawns, a witch inside and a cat with her, and no other structure in the world spawns a cat.

The swamp is also one of two biomes with the swamp variant of the ruined portal, and the mineshafts and chambers below it follow the ordinary pattern.