Taint is a form of magical corruption that spreads throughout the land and affects terrain, plants, animals and monsters. Taint isn't merely the byproduct of too much Flux in an area. Such zones also appear on world generation, as biomes with purple-tinted vegetation. The biome starts relatively tame, yet corrupts itself over time within its own borders; the latter tend to expand externally, too, but very slowly. Once you set foot in a Tainted place, not only does the world around you turn purple: the sky does too.
Nodes within those places often have the Tainted attribute; they are partly what causes the biome to spread.
Effects of Taint
Plants and creatures begin to change as a strange, purple growth appears and subsequently spreads everywhere. The ground will become a nasty, purple mud that squishes under your steps. Glowing weeds and Spore Stalks that spew poisonous gas clouds will start to grow everywhere. The gas from those pods will negatively charge the aura, which further increases the Taint rating and speeds up the corruption of the surrounding terrain.
Tainted areas are riddled with Fibrous Taint, Tainted Grass (some blocks even turn to Tainted Soil) and Tainted Plants and trees, whose wood becomes Crusted Taint.
Taint causes damage, in the form of Flux Taint, to every mob and player. When a mob dies in a corrupted area, it might become Tainted, and its behaviour is affected accordingly: normally docile creatures like pigs, cows and chickens will become aggressive and attack all uncorrupted life forms, including villagers and players. Tainted creatures include:
- Corrupted animals, like Tainted Sheep.
- Tainted Swarm (created by a spawner that looks like a kind of totem)
- Tainted Crawler
- Tainted Creeper
Tainted creatures are significantly stronger than their normal counterparts, and are healed within a taint biome. When a tainted creeper explodes, it will leave taint behind. A tainted sheep will spread taint, and tainted villagers will act as a mobile taint spore pod. These will be the tainted creatures you will most want to kill/stay away from.
Sometimes, when killed, a Tainted creature will drop Tainted Goo, or a part of a Tainted tentacle. When kept in the player's inventory, the goo starts to decay, causing slight damage each time the decay ticks. The item then vanishes from the inventory. This makes preserving them somewhat tricky—and you'll want to have some at hand for when the time comes to do some alchemy in your Crucible.
Tainted Goo and similar residual loot can be scanned using the Thaumometer, provided you leave them where they are while doing so, or quickly drop them out of your inventory as soon as you're back in a safer area.
It is possible to make artificial Tainted Biomes, although it is not recommended, all that is needed is an overloaded Crucible and a big and deep enough pit (a 7 x 7 x7) pit will be more than enough. The Crucible will expel Flux Goo, which is vital to making taint, beware the Elemental Slimes, that are born from the Goo.
Eventually Fibrous Taint will start forming from the goo, this is where the second step begins, an Aura Node has to be placed on the Taint, there is a random chance the Node will become Tainted, which will mean the process is complete.
The Tainted node will start to spread Fibrous Taint on it's surroundings and change Grass and Leaves into a purple color.
You can contain it's growth or stop it completely using the steps below
Preventing Taint from spreading is vital, as otherwise your crops, farms and whole bases could end up corrupted as well—especially if you've accidentally settled down near such an area upon starting a new game, and don't have any means to contain it yet.
Silverwood Trees and Pure Nodes
Silverwood trees are a natural bulwark against the spreading of Taint. Planting saplings near a corrupted area (but far enough for them not to be tainted while growing!) will help containing it. What matters most here isn't the tree itself, though, but the fact that it contains a Pure Node: in other words, Silverwood Trees without such Nodes at their core wouldn't be useful.
Pure Nodes can only clean Taint on small areas, and have a chance of being 'downgraded' when moved around, so you'll want to be careful when using this method.
This mystical plant can only be birthed in your Crucible. When planted in a land corrupted by mystical means—Taint included—it reverts it back to its normal appearance on a small area (8-blocks range). While Ethereal Blooms don't destroy Taint themselves, they cause its items and creatures to degrade, as they can't survive for long in non-corrupted land.
Keeping chunks from loading
Taint will not spread if it is located in an unloaded chunk. Another solution is thus to run away as far as possible from the corrupted area, until it isn't loaded anymore.
Taint is an intrinsic part of Thaumcraft 4's mechanics, and cannot be disabled. However, the mod's configuration file, found in your .minecraft/config folder (see below), can be edited as to modify how fast Taint spreads, or prevent it from spreading at all. In the latter case, the features of a Tainted biome will remain contained within it, much like those of any other type of biome.
In your minecraft/config folder search for "Thaumcraft.cfg". Open this file in notepad, then search for "biome_taint_spread". Its value should be around 200. If you set it to 0, the taint biomes will no longer spread taint in the area.