Snow Blocks, Mushroom grass, Ash grass, and bricks are useful examples of blocks that biome spread cannot convert in current Desktop, Console, and Mobile versions of Terraria. The important exception to a common mix-up: Snow Blocks resist spread, but Ice Blocks do not. Crimson and Hallow also spread, so “corrupted” here means affected by any evil-biome or Hallow conversion.
Blocks that resist biome conversion
| Block or tile | What happens | Important qualification |
|---|---|---|
| Snow Block | Not convertible by Corruption, Crimson, or Hallow spread. | Do not confuse it with Ice Block. The Corruption reference distinguishes Snow Block from convertible ice. |
| Mushroom grass | Cannot be converted by biome spread. | The biome spread reference says this holds at any stage of the game. |
| Ash grass | Cannot be converted by biome spread. | Also listed as immune at any stage by the biome spread reference. |
| Bricks | No brick types cause or can be converted by biome spread. | Useful for construction; see the bricks reference. |
| Wood and Hay | Named as non-corruptible building materials. | Listed alongside Dungeon Bricks in the world-purity guide. |
| Silt | Normally immune to Corruption, Crimson, and Hallow conversion. | It can be converted during the initial Hardmode V, so it is not immune in every circumstance. See Soil. |
Snow Block is not Ice Block
Ice Block can convert into Purple Ice in Corruption, Red Ice in Crimson, or Pink Ice in Hallow. Snow Block is a different tile and is not convertible. The conversion tables list many susceptible terrain families, including grass, stone, ice, sand, hardened sand, sandstone, and jungle grass.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
|
Two Point Hospital - Nintendo Switch | $45.39 | Buy on Amazon |
| 2 |
|
Minecraft - Nintendo Switch | $29.83 | Buy on Amazon |
Why an immune block may not protect a nearby build
Block immunity and containment are different things. In Hardmode, spreading tiles can convert susceptible blocks within three tiles; the spread reference describes this as a 7×7 area centered on a source tile. A strip of immune blocks one tile wide can therefore fail to protect vulnerable terrain close to the other side. Non-corruptible blocks in the path do not necessarily stop conversion.
For a general containment tunnel, the spread guide recommends an obstacle three tiles wide made of open air or non-corruptible blocks. Surface thorny bushes can extend farther, so a simple gap is not an absolute guarantee. The world-purity guide also recommends containment tunnels and covering exposed grass where thorns or vines could grow.
#1 Best Overall
- Build up a hospital from nothing to a masterpiece as you design the most beautiful – or functional – healthcare operation in the whole of Two Point County.
- Optimise your hospital design to increase patient (and cash) flow, arranging corridors, rooms and waiting areas to your exact specifications.
- Expand your hospital to multiple buildings as you look to get as many patients through the door as possible.
- Place decorative and functional items around your hospital to improve its prestige, lower patient boredom, increase happiness and keep those end of year awards flowing in.
- Features two great expansions, 21 hospitals and 119 very unusual illnesses!
- Account for the distance from spreading source tiles to susceptible blocks, not just the visible barrier.
- Cover exposed grass where thorn or vine growth could create another route.
- Vines themselves cannot be converted; the block they attach to can be converted.
- Actuated tiles do not spread biomes, but regular tiles can spread to actuated tiles.
Version scope
The main biome-spread reference covers Desktop, Console, and Mobile Terraria and notes separate behavior for Old-gen console and 3DS. The examples above describe the current main-version rules; do not assume they apply unchanged to those legacy versions. The references are maintained pages rather than dated patch notes, so game updates may change mechanics.
Quick Recap
Rank #2
- Minecraft is a game about placing blocks and going on adventures
- Explore randomly generated worlds and build amazing things from the simplest of homes to the grandest of castles
- Play in creative mode with unlimited resources or mine deep into the world in survival mode, crafting weapons and armor to fend off the dangerous mobs
- Play on the go in handheld or tabletop modes
- Includes Super Mario Mash-Up, Natural Texture Pack, Biome Settlers Skin Pack, Battle & Beasts Skin Pack, Campfire Tales Skin Pack; Compatible with Nintendo Switch only
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.




