The Corruption



The Corruption is a biome characterized by purple "corrupted" grass and trees, as well as the growth of Thorny Bushes that harm the player on contact unless cleared away with a weapon or tool. It is best to explore it mid-game when you have some of the better items (silver or gold equipment). Deathweeds can be found here.

Purification Powder can be used on corrupted blocks to turn them into their regular counterpart. Hallowed Seeds and Holy Water can also be used to create The Hallow, which Corruption will not spread through. Hallowed Seeds are not available until the world enters hardmode, but a player may bring them in from another world and plant them.

Many chasms dot the landscape in The Corruption. It is recommended that you don't explore these until you have a Grappling Hook or some other form of vertical transportation, as chasms can be hundreds of feet deep. Chasms are covered in Ebonstone, which can only be mined using a Nightmare Pickaxe or better or by using Bombs or Dynamite (which also destroy Shadow Orbs). Alternatively, Purification Powder can be used to turn the Ebonstone into normal stone, which can then be mined with any pickaxe. Chasms frequently house Demon Altars.

Caves can often be found surrounding the chasms, commonly containing Pots, Chests, and Life Crystals.

Corruption vs. "The Corruption"

 * Corruption is a purple grass-like substance that infects grass blocks and spreads quickly to any connected grass blocks, similarly to ordinary grass.
 * "The Corruption" is a term used to describe the biome that takes effect when a significant amount of Corruption exists in an area of the World; theme music is changed to The Corruption's theme, trees turn purple, the sky darkens, and corrupted enemies, such as the Eater of Souls and Devourer, spawn.

A small amount of Corruption can exist in other biomes, the same way Jungle Grass can exist in biomes that are not actual Jungle biomes, and Meteorite blocks can exist in biomes that are not Meteorite biomes. When a certain threshold of corrupted blocks is reached, the biome changes to The Corruption, with altered theme music and spawned enemies characterizing the corrupted biome.

Spreading Corruption
In normal mode, corruption can spread, but only under limited conditions:
 * Corrupt grass can spread in a manner similar to normal grass, converting adjacent dirt tiles with at least one side open to air (only in the Surface Layer).
 * Corrupt grass will grow over Hallow grass, and Hallow grass will grow over Corrupt grass. When the two meet, the results are unpredictable.
 * Corrupt grass can also displace normal grass, unless the grass has a Sunflower planted on it.
 * Corrupt grass may sprout Thorny Bushes, which can spread corrupt grass according to the same rules.

Naturally-occuring corruption will often be halted by various natural barriers (stone, desert, etc.) before it is even discovered, but care should be taken when creating an artificial corruption biome that it does not spread further than intended.

Hardmode Corruption
Once the Wall of Flesh is defeated, a world enters hardmode. New areas of Corruption and Hallow are immediately created that extend from the Underworld up to the Surface, sometimes going right through existing corrupted areas, and Corruption begins spawning more dangerous monsters—in particular, the Corruptor and (underground) the Clinger.

Corruption spreads much more aggressively once the world is in hardmode:
 * Dirt and grass can still be converted to corrupt grass.
 * Mud and jungle grass can now also be converted into corrupt grass (changing the underlying block type to dirt).
 * Stone can be converted to ebonstone.
 * Sand can be converted to ebonsand.
 * Sunflowers no longer block the corruption, and will be uprooted if the grass they are planted in is corrupted.
 * Corrupt grass is still limited to the Surface Layer, but ebonstone and ebonsand can spread through any depth.
 * Blocks that are up to three squares away from an existing corrupt block can be converted (even if incorruptible blocks are in the way).

In order to stop the spread of corruption in hardmode, the player may create a gap at least three squares wide containing no corruptible blocks as a buffer. It may contain other blocks, such as wood, but must be three spaces wide.

Another, perhaps easier, method is to create the Hallow, since it will spread similarly to and compete with Corruption. Keep in mind, however, that the Hallow, as a hardmode biome, will also spawn powerful creatures and is no less dangerous than hardmode Corruption. You will need both corrupted and hallowed areas to obtain all the new crafting materials.

Note that the Hallow is slightly more limited than Corruption in its spread; in particular, it cannot spread through mud or jungle grass. If you'd like to preserve your natural jungle, surrounding it with Hallow may be a good idea.

Corrupted Desert
When Corruption spreads through desert, it becomes Corrupted Desert. It is very similar to The Corruption: the theme music is the same, the mobs are the same (with the exception of the Dark Mummy), and the background is just slightly different.

Sand is replaced by ebonsand. Although their color is different, cacti still drop cactus when cut, and waterleaf is able to grow.

Getting through
The Corruption is infamous for being hard to get through. Here are a few pointers on making it through:
 * Defend yourself. Make sure you have at least Copper/Iron armor (silver or gold are recommended). In hardmode, Cobalt armor or better is recommended.
 * Have good weapons. Ranged weapons are useful in taking out the Eaters of Souls, especially if you use piercing ammo.
 * Don't fall down chasms. The deep Corruption chasms are a surprisingly large danger. Build a bridge out of commodity blocks or use an accessory or Grappling Hook to get across.
 * Having a Lucky/Obsidian Horseshoe or Angel/Demon Wings will prevent fall damage if you do fall into one. A Cloud in a Bottle or Grappling Hook may also be used to prevent such damage by jumping/grappling at the last second before hitting the ground; however, due to the lack of light, you may have little warning.