Guide:Artificial biomes

Artificial biomes are player-constructed biomes that will spawn the monsters and provide access to most of the other materials that this biome provides. Only certain biomes can be artificially constructed. These are useful for building gardens or otherwise farming for certain items. This guide will explain how to build such biomes.

Some biomes can be constructed within virtually any Layer, at any depth, while others have specific depth requirements. With the exception of the Meteorite biome, no biome will override the Underworld. Only biomes mentioned below can be constructed artificially.

General Tips

 * Seeds can be used to create/spread biomes over Grass. These include:
 * Grass Seeds, whose purpose is to convert dirt in Grass, helping to create more Forest or other biomes;
 * Jungle Grass Seeds, which is used to create the Jungle;
 * Mushroom Grass Seeds, which is used to create the Mushroom Biome;
 * Corrupt Seeds or Crimson Seeds, used to create their respective Evil biome;
 * Hallowed Seeds, used to create Hallow.
 * The Staff of Regrowth is handy for growing grass on dirt (and moss on stone).
 * Some throwable items can be used to spread or cleanse Corruption, Crimson, and Hallow: Purification Powder, Vile Powder, and Vicious Powder, and weapons such as Holy Water, Unholy Water, and Blood Water. All of them will be consumed on use.
 * The Clentaminator (sold by the Steampunker) is a very useful tool for making Artificial biomes: although it can be more expensive than other options, it is incredibly quicker than the other methods.

= Buildable artificial biomes = These biomes can be constructed within any location. The depth will determine for some biomes if it's in "surface" or "underground".

Forest
A Forest biome (also called "the Purity" in-game) is the default biome for the Surface layer. When none of the other conditions for a biome are currently fulfilled on the surface, then it is a forest biome.

A more proper forest can be grown by planting Grass Seeds on Dirt blocks. Trees can be grown with Acorns.

Using the Clentaminator with Green Solution will convert Corruption, Crimson and the Hallow, into Forest.

This biome is useful if you don't want to deal with Hallow enemies, which can be hard to deal with, or you need a Fishing spot for fish that only spawn here, or to get the material that you can only get here (like normal Wood).

Desert
A Desert biome is defined by the presence of Sand blocks, in any layer except the Underworld. Even a single block of sand can grow Cactus and Waterleaf. It requires over 1001 blocks of sand to change the background into the desert background, and the presence of sufficient other biome-defining blocks on-screen will override this background.

If you want to create an Underground Desert, you additionally need sandstone or hardened sand walls behind the player.

A flat strip of sand, one block in height, is sufficient for harvesting various Desert materials. However, making a proper desert (with the background), it can make it prone to Sandstorms, which can be used to farm Forbidden armor in Hardmode.

Hardmode Desert
Hallowed, Corrupted, and Crimson deserts can be constructed from Pearlsand, Ebonsand, and Crimsand, respectively, in Hardmode.

Players might want to build these variants to farm Hardmode desert enemies for loot, such as Mummies, as their Hallow and Evil counterparts are needed to get Light and Dark Shards.

The Clentaminator can be used to convert Sand into other variants:
 * Using Purple Solution will convert Sand into Ebonsand;
 * Using Red Solution will convert Sand into Crimsand;
 * Using Blue Solution will convert Sand into Pearlsand;
 * Using Green Solution on Hallowed, Corrupted, or Crimson deserts will convert them back into normal deserts;

Surface Jungle
The surface Jungle is defined by the presence of Jungle Grass, but only on the Surface layer. Jungle Grass will cause the spawning of surface jungle enemies, regardless of how many tiles are present. 80 blocks of Jungle Grass, including plants that grow in the tiles above Jungle Grass, are needed to change the background and music into the Jungle biome's natural music and background.

Unlike the Forest, Jungle grass naturally grows Rich Mahogany Trees, meaning you don't need acorns to get Rich Mahogany wood. Additionally, the Jungle is the main source of Moonglow and Sky Blue Flowers. It's also a source of Jungle Grass Seeds, which can be used to build your own Jungle.

The Jungle terrain is generally rough, and thus, it's a good idea to flatten and drain lakes around your farm spot, in order to farm its materials more efficiently.

Blocks from the Lihzahrd Temple work as well, for surface and the underground Jungle.

Underground Jungle
The Underground Jungle biome is defined by the presence of Jungle Grass in the Underground or Cavern layers. Which depth this is depends on the Map's size:

If you're building an Underground Jungle, make sure to protect it from eventual Corruptible blocks that can destroy your efforts once you enter in Hardmode. For example, place a thick Stone barrier (must be at least 3-blocks thick) around your jungle and use Holy Water around it.

An Underground Jungle built in Cavern layer contains:
 * The already mentioned Surface materials (Rich Mahogany Trees, Moonglow, Sky Blue Flowers);
 * Hornets, which drop Stingers;
 * Man Eaters, which drop Vines;
 * Jungle Spores, Jungle Roses and Nature's Gift can grow.

Additionally, in Hardmode:
 * Creating Patches of Mud can create Chlorophyte veins;
 * Life Fruits can spawn, which are needed to increase maximum health to 500;
 * Turtles, which can drop Turtle Shells;
 * Plantera's Bulb, which can be used to spawn Plantera.

Snow
A Snow biome is defined by the presence of 300 or more Snow Blocks, Ice Blocks (including pink, purple, and red variants) or Snow Bricks. This will change the background and music into the Snow biome ones. Below the cavern layer, Underground Snow will be created instead.

Some Snow biome enemies require the presence of Ice Blocks to spawn, while others will appear along with the biome background and music, with particular enemies depending on depth and whether it's raining/snowing or not.

It's useful to farm Boreal Wood and Shiverthorns, which can only grow in Snow, and Frost Core in Hardmode.

Ocean

 * An Ocean biome is defined by all of the following conditions:
 * The floor must be made of Sand at least one block thick. Pearlsand, Ebonsand, or Crimsand does not count.
 * There must be 2 or more tiles of Water atop the sand for Ocean monsters to spawn.
 * 7 or more tiles of water for Coral to grow.
 * This must be positioned within 250 blocks of either edge of the map.
 * This must be above a depth of 0, so within the Surface or Space layers.
 * There must be 1,000 tiles of connected liquid in order to catch ocean fish.
 * Cannot use lava, honey or other liquids besides water.

Hallow, Corruption, and Crimson
The Hallow and Corruption biomes are defined by the presence of their respective hallowed and corrupted blocks, in any layer other than the Underworld. At least 100 Hallowed Grass, Pink Ice Block, Pearlstone, and Pearlsand defines the Hallow; tiles with hallowed plants (including 2-tile tall plants, but not trees) growing on top of hallowed grass also count. At least 200 Corrupt Grass, Purple Ice Block, Ebonstone, and Ebonsand defines the Corruption, with each tile of Vile Mushroom, Thorny Bush and other corrupted plants growing on top of grass counting. At least 200 Crimson Grass, Red Ice Block, Crimstone, and Crimsand defines the Crimson. Note that for purposes of defining a biome, each block of Crimson or Corruption will subtract 1 from the total count of Hallow blocks and vice versa.

If the world is pre-Hardmode, an artificial Hallow biome will not spawn its usual monsters; it will spawn Forest monsters instead. It will spawn Lightning Bugs, instead of Fireflies, however.

Underground Hallow, Corruption, and Crimson
The criteria for the Underground Hallow, Underground Corruption, and Underground Crimson are the same as for the standard versions of the biomes, only that the player needs to be at Underground or Cavern layer or lower.

In Pre-Hardmode, Hardmode enemies will not spawn.

Meteorite
The presence of 50 meteorite ore on the screen will transform any environment into a Meteorite biome. All naturally-occurring enemy spawns will be replaced with Meteor Heads, unless this is done in the ocean biome. This works even in the Underworld.

Mushroom
A Mushroom biome is defined by the presence of Mushroom Grass, at least one exposed block of which will spawn Mushroom biome enemies if above the surface level of the world. At any depth, this grass will also sprout 1-block-tall Glowing Mushrooms and multi-block Giant Glowing Mushrooms. At least 100 tiles of mushrooms or mushroom grass are needed to start seeing changes to the music and background, although changing the water color in the biome may take more. Underground Mushroom Biomes do not spawn within Underground Snow or Desert Biomes.

= These biomes can be augmented, but not moved = Several biomes require that the player stand in front of a specific natural background wall to spawn the particular biome enemies. The existing biome may be enlarged, creating more space for the enemies to spawn. Background walls placed by the player will block enemy spawns.

Underground desert
The underground desert must be in the underground or caverns layer of the world and is found under one of the desert biomes in the world. There will be a large tunnel leading down into it from the desert biome. Despite possibly having multiple deserts a world may only have one entrance to one underground desert. The sandstone walls are naturally generated there and cannot be gathered. The sandstone walls or hardened sandstone walls(not currently in game) must be with sufficient sand, sandstone or hardened sandstone for the true biome.This attribute is similar to the spider nest and makes an artificial underground desert impossible.

Dungeon
The Dungeon must be below the surface level of the world, and consist of at least 250 blocks of Dungeon Brick. The player must also be standing in front of a naturally-placed Dungeon Wall -- if the player removes and replaces the wall at the same location or elsewhere, it will no longer count towards the requirement, making it impossible to create artificial Dungeon biomes elsewhere.

Furthermore, for a dungeon NPC to spawn, there must also be a natural dungeon wall tile directly above a dungeon brick surface, ensuring they never appear just outside of dungeons. Being in a dungeon biome prevents any non-dungeon NPCs from spawning. So if there is no appropriate spawn surface for dungeon mobs (brick and wall), then *all* spawns are blocked.

Spider Nest
A Spider Nest mini-biome is based on the presence of the special mottled grey/brown cave wall in these areas. Blocks in front of these walls will accumulate Cobwebs up to three tiles deep, and Wall Creepers (pre-Hardmode) and Black Recluses (in Hardmode) will spawn. It's not possible to move or collect this cave wall, so artificial biomes can't be created elsewhere, but a player could set up blocks in an existing nest to affect spawning / allow collection of Cobwebs.

Underworld
The Underworld is defined as roughly the bottom 200 blocks of any world; at around this level, the music and background changes, Underworld enemies will spawn, and water will generally evaporate. An artificial Underworld cannot be created at any other depth.

Lihzahrd Temple
A naturally occurring Lihzahrd Brick Wall behind the player is required for Lihzahrd and Flying Snake spawns. Thus, while the player may create spawning areas for these enemies by placing Lihzahrd Bricks, proximity to a natural Temple is still necessary. Walls placed by a player, in game, actually block (all) spawns.

Lihzahrd Bricks count as Jungle biome blocks, and can be used to create an artificial Jungle biome, greatly increasing the Spawn Rate and NPC cap (in the forest or desert, for example), or to permit the summoning of Queen Bee.

= Calculation Mechanics =

Qualifying Blocks: Only blocks within a rectangular zone 50 tiles left and right, and about 43 tiles vertically, of the screen's centre are counted towards determining active biomes. At the edges of the world, when the screen stops scrolling, this reference point no longer matches the player's position.

For biome influencing walls (e.g. dungeon and lihzahrd brick), only the one tile directly behind the middle of the player's sprite is considered. This moves with the player at all times, even at the world's edges.

The reference point determining biome depth appears to be the top of the screen. When at a transition between Layers, resizing the screen may change the active biome, even while player remains totally static.

When the criteria for multiple biomes are met simultaneously, there is an order of precedence for which one sets the music, background scenery, spawn rate, innocent NPC spawns, etc. However, multiple biomes may be active simultaneously. This allows, for example, the possibility of two or more Biome Key(Biome Key Mold) drops within one area.