What Blocks Cannot Be Corrupted in Terraria?

The world of Terraria is a vast and exciting landscape filled with adventure, exploration, and, of course, the ever-present threat of corruption. Whether you’re dealing with the insidious spread of the Corruption, the bloody tendrils of the Crimson, or the seemingly benign but equally invasive Hallow, understanding which blocks can resist these biome shifts is crucial for any aspiring Terrarian. The short answer: most blocks, excluding stone, sand, grass, ice, and some biome-specific variants, are immune to the spread of corruption, crimson and the hallow. This means a wide range of materials can be used to fortify your base and strategically limit the spread of the world evils.

Building Your Defenses: Immune Blocks

Knowing which blocks are invulnerable to these biome conversions is essential for establishing safe zones and controlling the expansion of unwanted biomes, particularly during Hardmode. Here’s a breakdown of the most common blocks that cannot be corrupted:

• Wood: All types of wood are safe from corruption, crimson, and hallow. This makes wood an excellent early-game building material for creating barriers and safe houses.
• Clay Blocks: These blocks, easily made from naturally occurring clay, are completely impervious to biome spread, offering a readily available resource for defense.
• Ash Blocks: Plentiful in the Underworld, ash blocks provide another easy-to-obtain and reliable material to halt the spread of biomes. Their non-corruptible nature makes them invaluable for creating wide barriers or detailed structures.
• Silt Blocks: Often found in underground layers, silt blocks, like their ash and clay counterparts, also resist corruption. This gives players another easily sourced option to defend against the corruptive forces.
• Obsidian: Formed when water comes into contact with lava, obsidian’s resistance to corruption makes it a functional and aesthetically appealing choice for base protection.
• Ores: All types of ore, from copper to chlorophyte, are immune to biome spread, meaning you can build structures or barriers using these raw materials without worry.
• Gems: Similar to ores, gems do not get corrupted, so you don’t have to worry about them converting into something unpleasant.
• Bricks: Generally, most bricks are safe. This includes Gray Brick, Red Brick, and others, allowing for versatile construction and solid defenses. However, it is essential to note that Pearlstone bricks, a Hallow variant, will spread the Hallow.
• Furniture and Crafting Stations: Constructed furniture and crafting stations are not affected by corruption, crimson, or hallow. This ensures your workshops stay in pristine condition.
• Mushroom Grass: The unique properties of mushroom grass mean it is completely safe from corruption, crimson, and hallow, making it an ideal biome to develop, especially for the Truffle NPC.

Practical Applications

Knowing which blocks are immune allows you to be strategic in your builds and in your defense measures. For instance, creating a trench using a combination of clay, ash, or wood can prevent biome spread. These trenches should be at least three blocks wide, but preferably six blocks wide for extra protection, to ensure the affected blocks do not spread past them. You can use these blocks to create entire barriers around your base, ensuring that your living space remains free of the corruption, crimson, or hallow.

Frequently Asked Questions (FAQs)

Here are some frequently asked questions to clarify common confusions about block corruption in Terraria:

1. What blocks are vulnerable to Corruption and Crimson spread?

Primarily, Stone, Sand, Grass, Ice, Vines, and Demonite Ore (for Corruption) are all susceptible to corruption and crimson. These blocks will transform into Ebonstone/Crimstone, Ebonsand/Crimsand, Corrupt/Crimson grass, Corrupt/Crimson ice, and Corrupt/Crimson vines. These are the blocks to be most wary of. The Hallow will spread to Grass and Flower Walls.

2. Does the Hallow spread to the same blocks as Corruption and Crimson?

The Hallow will primarily spread to the same types of blocks as corruption and crimson, so Stone, Sand, Grass, and Ice. However, it won’t convert Demonite Ore, which is exclusive to corruption. Pearlstone also has hallowing capabilities like ebonstone does with corruption.

3. Can mud be corrupted?

Yes, mud has its own corrupted variants (corrupted mud, crimson mud, and hallowed mud). However, it doesn’t convert into dirt when corrupted or hallowed.

4. How can I contain the spread of Corruption/Crimson/Hallow in Hardmode?

During Hardmode, biomes spread more quickly. To control it, use non-corruptible blocks like wood, clay, ash, silt, or bricks to create wide barriers or tunnels around affected areas. Also, consider utilizing the Clentaminator to cleanse affected regions, though this will require a good amount of solution.

5. Do Sunflowers really stop corruption?

Yes, sunflowers do have an impact. The two tiles directly beneath them are protected from corruption, crimson, and hallow. They also decrease the corruption rating of the area, making them helpful, but cannot replace a strong barrier.

6. Does breaking Demon Altars cause more corruption?

Yes, each time you break a Demon Altar, there is a 66.67% chance of a single random Stone Block in the Cavern layer being converted into Ebonstone or Crimstone, or Pearlstone, facilitating the spread of these biomes, but this isn’t a large amount compared to a new hardmode world spawn, which is why you are able to break a multitude of demon alters to obtain ore.

7. Can Lava stop corruption spread?

Yes Lava will burn any grass that is on the surface, effectively stopping the spread of crimson. However, this effect is not confirmed in corruption biomes.

8. Is it true that some ores can’t be corrupted?

Yes, absolutely! All ores and gems are immune to corruption, crimson, and hallow. This is great because it means you can safely use them for building.

9. Can sandstone brick be corrupted?

Yes, like the normal sand block, sandstone bricks are also corruptible in Hardmode and have their own Ebonsandstone, Crimsandstone, and Pearlsandstone variants.

10. How far can corruption/crimson jump?

Corruption and crimson can spread up to six tiles in all directions. They spread their biome up to three blocks away, but are stopped by any non-corruptible block.

11. Do Demon Altars count toward the total corruption percentage?

No, Demon Altars do not count toward your total corruption percentage. They can contribute to spread, but they do not count as part of the total corrupt/crimson in the world.

12. Can NPCs live in the Hallow?

Yes, NPCs can live in the Hallow without any issues, unlike the Corruption or Crimson. This can often be advantageous to set up your base.

13. Can Mushroom biomes get corrupted?

No, Mushroom biomes are not affected by corruption, crimson, or hallow. Your mushroom grass will always be safe.

14. What is the most effective way to purify a world?

The most effective way to purify is using the Clentaminator with Green Solution (if you are aiming to turn a biome back to its normal state). The solution can be purchased from the Steampunker and is a very quick way to cleanse your world.

15. What is the strongest block in Terraria?

Lihzahrd Bricks, from the Jungle Temple, are the strongest block, being impervious to explosives and breakable only with the Picksaw or better. However, they are not relevant to biome corruption.

Conclusion

Understanding which blocks are immune to corruption, crimson, and the hallow is crucial for any Terraria player. By using materials like wood, clay, ash, silt, bricks, obsidian, ores, and gems strategically, you can protect your bases, contain the spread of world evils, and effectively manage your Terrarian world. Always remember to build trenches and barriers at least three blocks wide and explore options like the Clentaminator to keep your world safe and prosperous. Now that you’re equipped with this knowledge, you’re ready to build, explore, and conquer Terraria with confidence!