The Crimson is an evil biome with a fleshy infection, red gore theme, in contrast to the dark purple wasteland theme of its counterpart, the Corruption. Every world will contain one of the two generated randomly except for special seeds (each with a 50% chance of occurring) or chosen by the player upon world creation ( only after the Wall of Flesh has been defeated in any world). Both contain similar hazards and feature their own unique enemies, items, and blocks. The tools, weapons, and armor obtained via Crimson material generally have minor advantages over those obtained via Corruption materials; however, Corruption tools are slightly faster. Crimson enemies tend to have slightly higher stats, such as health, defense, and damage.
The Crimson contains multiple chasms, extensions of the biome into the underground. Every chasm has an entrance on the surface and leads to a large, circular cavity, then branches off into small "fingers" which end with a Crimson Heart. Crimson Altars generally line the chasm's passages, appearing inside and around it. Chasms consist of Crimstone, which can be blown up by explosives, mined with a Nightmare/Deathbringer Pickaxe or higher, or purified to Stone by using Purification Powder.
The Crimson spreads, meaning it slowly converts adjacent tiles to their Crimson variants. See below for details. Chasms, Crimson Altars, and Crimson Hearts will only appear upon world generation, and will not spawn in a Crimson area that has formed through spreading. If enough Crimson manages to take over a new area, then that area will eventually adopt the Crimson's theme music, background, and water color. For an area to be considered a Crimson biome, at least 300 / 200 tiles of Crimson grass or Crimson blocks must be present. Thorny bushes will begin to sprout on the grass and will damage the player when touched.
The Crimson spreads itself, similar to the Corruption and the Hallow. This means that it slowly converts certain susceptible tiles that are in the vicinity of existing Crimson blocks. While its spreading capabilities are very limited during pre-Hardmode, it spreads much faster and more aggressively after defeating the Wall of Flesh. Defeating Plantera for the first time reduces the speed of the Crimson's spread by
In Hardmode, Crimson spreads through Deserts, transforming them into Crimson Deserts. A Crimson Desert is fairly similar to a regular patch of Crimson: The theme music and enemies are the same, with the addition of:
- Surface Desert:
- Underground Desert:
Sand is replaced by Crimsand. Cacti drop ordinary cactus when cut, even though they have a different color. Waterleaf is not able to grow in Crimson Deserts. If a Crimson biome overlaps a Desert biome during world generation, Sand will be converted to Crimsand, but it will not spread until Hardmode.
Like the Crimson desert, Crimson Snow biomes are created when a Crimson spreads into a Snow biome during Hardmode. Snow is not convertible, but Ice can be converted into Red Ice. Red Ice can be created during generation if a Crimson biome overlaps a Snow biome, but it will not spread until Hardmode.
- Crimson can be created or spread artificially using Crimson Seeds, Vicious Powder, Blood Water, or the Clentaminator with Red Solution, obtainable from the Steampunker during a Blood Moon in Crimson worlds (she sells Purple Solution in a Corruption world instead).
- As of version 1.4 of the game, it is possible to create an artificial Corrupt biome in a Crimson world without the use of another world. To do so, one must buy Corrupt Seeds in Hardmode from the Dryad while in a Graveyard.
- Artificially creating a new Crimson biome requires at least 300 Crimson blocks. Although Corruption might replace Crimson at world generation, it does not prevent Crimson from being artificially created in a Corruption world, and vice versa. Spreading remains normal.
- Any enemy in the Crimson or Underground Crimson has a
0.04*1/2500 (0.04%) chance to drop a Crimson Key / Crimson Key Mold in Hardmode.
- The Steampunker will only sell the Flesh Cloning Vat and Red Solution in a world that naturally generated with Crimson. Artificially creating a Crimson biome in a Corruption world will not cause her to sell these items.
- Trees in the Crimson do not drop Acorns.
For elaborate strategies on surviving in the Crimson, including detailed gear recommendations, see Guide:Surviving in the Crimson.
- Early on, determining whether a world contains Crimson is possible in the following ways:
|The tree in world selection (on the right: during Hardmode)|
- During world generation, one half of the progress bar will be green, and the other half red (purple for Corruption worlds). Additionally, the bar on the inside will be yellow (lime green for Corruption worlds), representing Ichor. The step in the world generation process in which the Crimson is created is called "Making the world bloody" ("Making the world evil" for Corruption worlds). Also, a tree at the side of the world name in the world selection has one green/normal side and one red side (purple for Corruption worlds).
- Occasionally, two chasms might overlap, causing a sort of "cross" or "X" pattern, as seen in the image to the right.
- Because of the large circular cavity, its out-warding branches, and the entrance tunnel cutting at sharp angles, the chasm has many interpretations:
- A cartoonish hand with its fingers outstretched.
- A heart connected to veins, because of its red theme.
- These chasms could represent the body of a neuron, a cell in the brain, evidenced by its associated boss, the Brain of Cthulhu, while the Corruption chasms resemble worm tunnels and has a worm-like boss, the Eater of Worlds.
- The entrance of the chasm has teeth-like stalactites and stalagmites, and could be interpreted as the entrance being the mouth of a beast.
- The interpretations of the above-mentioned trivia notes would make sense with the Crimson's gore-like theme.
- Many Crimson enemies have deformed features or blisters that resemble cancerous growths. This contrasts with the rotten bodies of many Corruption enemies, sometimes with green pus dripping out of them.
- During a Blood Moon, three critters turn Vicious (Vicious Bunny, Vicious Goldfish, and Vicious Penguin), a reference to the Crimson. They can also manually be turned Vicious with Vicious Powder.
- – According to the official game lore, the Crimson is a living being who wants to balance the world, and the creatures who come from it used to worship the Crimson. It acts like a hive mind connected to all worlds. The being itself is unseen.
- If you use the seed 05162020 in 1.4, you'll have both the Crimson and Corruption in the same world, along with Living Trees having Moon Lord Legs and Red Potion inside their chests.
- The crimson could be a reference to the corruption bacteria from the Dead Space series.
- The shade of Crimson grass appears to be almost the exact same shade as inverted Hallowed grass.
- The achievement "Corruptible" refers to the Corruption. However, the Crimson appears to have no Crimson achievement equivalent.
- On the Desktop version, Console version, Mobile version, and Nintendo Switch version, the Surface Crimson Biome can sometimes show a Crimera floating in the background.
This content is transcluded from Biome backgrounds § The Crimson.
- Desktop 1.4.1:
- Desktop 184.108.40.206:
- Added three new backgrounds.
- Added Otherworldly Crimson track from the cancelled Terraria: Otherworld.
- Desktop 220.127.116.11:
- Desktop 1.2.3: Crimson Deserts now have the proper water color. Added unimplemented crimson monster sounds.
- Desktop 18.104.22.168:
- Desktop 1.2: Introduced.
- Console 1.02: Introduced.
- Switch 1.0.711.6: Introduced.
- Mobile 1.2.6508: Introduced.
- 3DS-Release: Introduced.