Talk:The Corruption

Merged into the Environments page
This article, while well written, is so small that I'd say we merge it - along with all the rest of the biome pages - into the overarching Environment page. MarekkPie 14:58, 23 May 2011 (UTC)


 * No No, against it. Overview Pages with links to more specific ones are fine (except we are talking about armor pieces or mob size variations) – Flying sheep 20:14, 25 June 2011 (UTC)

"The" Corruption
May I ask why exactly is it "the" Corruption? Why not just "Corruption"? --Demian 17:15, 26 May 2011 (UTC)
 * It is not a common occurrence compared to the actual amount of land that is on the server, it is also randomly generated as a separate "entity" if you will as it causes a complete environment change. At least that is how I see it.--Thanatos 18:51, 26 May 2011 (UTC)

Thorny Bushes
We should somehow explain that these grow here. – Flying sheep 20:14, 25 June 2011 (UTC)

Monster Spawns
I think the page should say how much corruption grass or ebonstone it takes for monsters to spawn or for Eater of Worlds to be fought.

Corruption "spread"?
It's not very clear what it means when it says sunflowers can be used to stop the corruption from spreading. The article doesn't talk about spreading anywhere else, so I don't quite understand what that means. Is this something the biome itself does? Is it possible - if you were to remove all sunflowers from your map - to turn the whole world into a corruption biome? Or is this just referring to those purple viney corruption bushes? How fast is the spread? Is there a limit to the distance it's allowed to cover? I think there's a lot left uninvestigated here 98.151.233.238 09:16, 13 August 2011 (UTC)
 * The spread is just the purple grass. It spreads, like basically any other sort of grass in the game, but it can also spread to dirt blocks that already have normal grass on them. It's true that Sunflowers planted on grass stop this spread, but so does a single block that's not dirt. The real function of Sunflowers seems to be offsetting "evil" tiles -- if one plants 40 Ebonstone blocks and 1 Sunflower, the sky would remain normal. --Lunboks 11:20, 13 August 2011 (UTC)
 * I just added a section that differentiates between 'Corruption' and 'The Corruption' terminology that will hopefully clarify this.  Equazcion ( talk ) 11:23, 13 Aug 2011 (UTC)
 * PS to answer your questions, there is no real limit to how far Corruption can spread, but naturally-occurring Corruption areas created during World generation seem to be limited to their original areas. Corruption can also be started using Corrupt Seeds, and I don't believe that is limited -- any contiguous dirt blocks will eventually develop Corruption. A Sunflower placed in the path of Corruption will act as a border where Corruption can not spread past.  Equazcion ( talk ) 11:26, 13 Aug 2011 (UTC)

Clay can be used to stop corruption too. -Anonymous

Extent to how much the Corruption can spread / be stopped
You will need the holy water craft a bunch talk k to the dryad how much corrupt there is We should discuss the extent of which certain items can spread / stop the Corruption. Some of these items include: The modes involved are pre-Hardmode and Hardmode.
 * Purification / Vile powders,
 * Sunflowers,
 * Hallowed / Corrupt seeds,
 * Holy / Unholy waters.


 * Whether sunflowers / Purification powder will still stop corruption in pre-Hardmode (as of v1.1)
 * Whether spraying Vile powder / Unholy water, or planting Corrupted seeds in The Hallow will cause corruption

Any comments? Dragomir7 04:05, 4 December 2011 (UTC)


 * Here's what I've figured out:
 * In normal mode, corrupt grass can spread anywhere regular grass could (dirt blocks with at least 1 exposed surface above a certain minimum depth), and can displace normal grass unless that normal grass has a sunflower planted in it. Naturally-occuring corruption will probably have its progress halted by various natural barriers before you even discover it.
 * In hardmode, corruption can displace normal grass even if it has a sunflower on it (the sunflower is uprooted, just as if a player had mined the dirt underneath). It can also spread through stone and sand, turning them into ebonstone and ebonsand, respectively.  It doesn't appear to corrupt ores or any artificial blocks (wood, bricks, glass, etc.), but it can now cross virtually all the natural barriers that would have stopped it in normal mode, both on the surface and (importantly) underground.
 * Direct contact does not seem to be required in hardmode; it looks like it jumped across my hellevator (2 spaces wide air gap). I don't know yet whether it can jump across uncorruptible blocks or only air gaps, or exactly what the range limit is.
 * The wiki page says corruption can gradually convert mud into dirt in order to spread through it. I have neither confirmed nor disproved that.
 * Hallow seems to spread according to analogous rules, except that sunflowers can grow on hallowed grass, so they don't get uprooted. I also suspect it spreads a little more slowly than corruption, but it's hard to be sure.
 * Additionally, hardmode corruption spawns corruptors, which have a projectile attack that they aim at players but that will corrupt any ground it happens to hit. This can even corrupt hallowed areas, so be careful fighting at the borders of corruption that you'd like to contain, even if the area is already hallowed.
 * Purification Powder will convert corrupted grass, ebonstone, or ebonsand back into their uncorrupted versions. (Of course, the corruption can always spread to them again.)  Hallowed Seeds can only be planted in dirt (not grass, stone, etc.); if planted underground (where grass normally can't grow), the hallowed grass won't spread, but it can still turn nearby stone/sand into pearlstone/pearlsand and create a hallowed biome.  Holy Water hallows any blocks that have hallowed versions (dirt, grass, stone, sand), and can even be used directly on corrupted blocks (though a small patch of hallow surrounded by corruption doesn't buy you much).  A single hallowed seed makes 5 vials of holy water, so this is a much more cost-efficient way to spread hallow as soon as you collect a bit of Pixie Dust.  I haven't used vile powder, corrupt seeds, or unholy water, but I would expect them to follow analogous rules.
 * I'm pretty sure it should be possible to build some sort of barrier that will stop the spread of corruption without resorting to hallow, but it looks like it may need to be fairly thick, and it would need to completely surround the corruption (including underground) to contain it. Since hallow spreads on its own, it is by far the easiest containment option.
 * Of course, you need both corrupted and hallowed areas in the world to farm all the crafting materials you'll want, and hallow appears to be only marginally less dangerous than corruption, so a roughly 50/50 split may be ideal anyway. --Manxome 08:14, 7 December 2011 (UTC)


 * This is a very good post with a lot of accurate and helpful information. I'd say all of this information should definitely be in the article. I have only one thing to add. Corruption will convert mud and jungle grass into dirt, and then corrupt it. Hallow does not have this effect. --GauHelldragon 08:29, 7 December 2011 (UTC)


 * Just posting to add that the range of Hallow/Corruption spread might be VERY large, at least vertically. I need to experiment on a fresh world, to double confirm this, but on a friend's world, the stone bridge we built for fighting the wall of flesh had converted partially into Hallowed/Corrupt blocks, and the closest ones were above the underworld's Ash Cieling. (His Hellevator was on the border of the 2) I intend to do more testing, to get more concise information. -- Teeto K 16:28, 7 December 2011 (UTC)


 * Did some controlled testing. Ebonstone and pearlstone can both convert regular stone blocks that are up to 3 spaces away (that is, with 2 empty spaces between them at the target block).  Placing a wood wall in the way does not prevent this.
 * They cannot convert a stone block that is 4 spaces away (or at least, they didn't do so within 6 game days--long after everything else in the test area was converted). So a 3-space-wide gap may be enough to block them.  (I'm guessing that Teeto K's experience above was due to immediate creation of hallow/corruption upon beating the boss, and not as a result of surface biomes spreading downward.)
 * Additionally, I can confirm that corruption, but not hallow, can spread through mud (whether it has jungle grass on it or not), turning it into corrupt grass. It didn't appear to convert it into regular dirt as an intermediate step (just instantly to dirt with corrupted grass), but I didn't watch it constantly.
 * Interestingly, a block of regular dirt that I put next to the pearlstone was NOT converted into hallow grass (though dirt next to the ebonstone was converted to corrupt grass). This suggests that perhaps hallowed grass can only spread from hallowed grass, and not from other hallowed materials.  I wonder if that's a bug.  Sand was converted to pearlsand.
 * Now that my information is more definite, I'll update the article accordingly. --Manxome 08:28, 9 December 2011 (UTC)


 * Based on further testing, I think that neither ebonstone nor pearlstone can convert dirt blocks to anything. In my previous test, I now believe the ebonstone converted mud into corrupt grass, which then spread to the nearby dirt.  However, in tests where there is no mud or existing grass near the dirt, it doesn't seem to be converted.
 * Incidentally, this also answers whether ebonstone converts mud directly to corrupt grass or into dirt and then into corrupt grass--the conversion must be direct, since if the mud turned into virgin dirt at any point, it could not be converted further! Very strange.
 * Since this implies that corruption and hallow are not spread in the same way by all varieties of corrupt/hallowed blocks, still more testing may be in order to determine exactly what can convert what. Should probably also test whether regular grass follows different rules from plain dirt. --Manxome 02:12, 13 December 2011 (UTC)

As of 1.2.4.1, sunflowers are not uprooted bt the Corruption, only Crimson. Two sunflowers placed side-by-side can still block Corrupt grass in Hardmode, though the corruption can still circumvent the sunflowers through other block types. --137.151.175.64 19:37, 17 September 2014 (UTC)

Spreading
Can the Hardmode Corruption spread through a 2 block wide tunnel of air? --Mister X 14:16, 6 December 2011 (UTC)


 * Yes. At least, that is what I infer happened, judging from the aftermath in my hellevator, which was close to pre-existing corruption on only one side and now has large, matching swathes of ebonstone on both sides. --Manxome 07:47, 7 December 2011 (UTC)
 * This could be due to Corrupted Thorns, which spread the corruption too. 71.87.116.224 07:50, 7 December 2011 (UTC)
 * Corrupted thorns do not sprout directly from ebonstone, as far as I'm aware, and this was too far underground for corrupt grass. I also think I would have noticed if the hellevator was choked with corrupt thorns when I first discovered the ebonstone deposits.  And it didn't cross on the surface and spread downward, since I blocked the corruption's spread on the surface and there's hundreds of feet of regular stone above (and below) the ebonstone. --Manxome 08:20, 7 December 2011 (UTC)
 * Hm, 178.45.88.171 says that when you defeat the Wall of Flesh, it instantly creates streaks of hallow and corruption extending up to the surface. That's another possible explanation for what happened to my hellevator.  Maybe I'll have to set up some tests and see whether I can get the corruption to jump an air gap under controlled conditions. --Manxome 08:23, 8 December 2011 (UTC)

I've been firewalling the natural Corruption in my world by mining a large airgap of >5 blocks all the way around it (I'm a paranoid bastard), so this discussion is of great interest to me. When I get around to defeating the Wall Of Flesh I'll check if any of the Corruption has managed to spread beyond it. - Spinfx 21:26, 13 December 2011 (UTC)
 * I've yet to see corruption jump an air gap of 3 blocks or more under controlled circumstances; however, various other wiki editors have written that a streak of corruption is created when you defeat the Wall of Flesh, and that there is a chance of new corruption or hallow appearing in a random part of the world each time you destroy a demon altar with the Pwnhammer (which you'll probably want to do a minimum of three times), so what out for that. --Manxome 00:22, 14 December 2011 (UTC)
 * Oh crap, I totally forgot about the additional corruption, thanks for reminding me. I wonder how extensive those are and if it's worth attempting to box them in. Great, now I get to spend more money on explosives. - Spinfx 14:45, 14 December 2011 (UTC)
 * Edit: Just saw the next section below. I'm screwed. However, they don't appear to create blocks out of nothing so large airgaps should still be effective. It's just that once hardmode starts I'd need to quickly update my map and start firewalling critical areas ASAP. Gonna need explosives by the truckload, oh boy. - Spinfx 02:55, 15 December 2011 (UTC)

Hardmode Corruption/Hallow creation
Here's a world immediately after activating hard mode:



Here's a world after letting both corruption and hallow to spread, mining enough hardmode ore to get full Hallowed gear, and breaking several demon altars:



I ran about ten tests on four different worlds and they always followed this rough shape with Hallow on the left. There's a lot to be learned from these images, but I can't decide the best way to put it into the wiki. Open to suggestions. --Theothersteve7 15:45, 14 December 2011 (UTC)


 * I haven't used this sort of map viewer, but my hallow reached the surface somewhere on the right side of the map (in the middle of one of the initial corrupt areas, actually). Perhaps it has something to do with where you summoned or killed the Wall of Flesh?  Mine was moving from left to right, and it is at least vaguely plausible that my corrupt/hallow streaks were centered on the location where mine died. --Manxome 17:33, 14 December 2011 (UTC)
 * It's not centered on the location nor where WoF was summoned, nor where WoF was defeated. That's for sure. Rather targeted somewhere nearby to spawn point/center of the map.
 * You'll notice that there are random splotches on the second map. Every time you destroy a demon altar, you get a splotch of either hallow or corruption somewhere in your world.  I would _guess_ that Manxome's map simply has one of those splotches on the right side near the surface.  Not ruling out the ideas that I just got very unlucky or there's another factor involved. --Theothersteve7 18:08, 14 December 2011 (UTC)


 * Worthwhile thought, but not a chance.
 * First, it definitely appeared before I smashed any demon altars--I tried to avoid reading wiki info on hardmode before playing it a bit myself, and it was quite some time before I figured out that smashing demon altars was a worthwhile thing to do (I initially assumed it just let me relocate them, and there was a naturally-occuring one directly below my home already). In fact, the very first demon altar I smashed was actually INSIDE of this hallowed area!
 * Secondly, the hallowed area is huge, and right in the middle of a formerly-corrupt area. At least two entire corrupt chasms were converted to pearlstone, along with a matching segment of the corrupt tunnel beneath them, and a large area underneath that; it is wildly implausible that such a large (and linear) area previously filled with corruption could have been grown over with hallow from a small seed area.  There was definitely a large, near-vertical swathe that was converted en masse.  And it's definitely substantially to the right of the map's center/initial spawnpoint (verified my initial spawn is at map center with a compass).
 * Thirdly, there was definitely NO naturally-occuring hallow on the left side of the surface of my world. Pretty much the first thing I did was travel left and plant some hallowed seeds, but the only hallows on the surface there are the ones I personally planted; I traveled all the way to the ocean and didn't encounter any pre-existing hallows on that side of the map.
 * Conversely, I saw illuminated slimes and bats at the base of my hellevator immediately (less than a minute) after killing the Wall of Flesh for the first time. And my hellevator is slightly but distinctively on the left side of my map.  So if the initially-created hallow is all a single streak, it definitely has to be stretching from bottom left to top right (mirror image of the pictures above). --Manxome 20:33, 14 December 2011 (UTC)
 * Very impressive! I applaud your thoroughness.  This indicates to me that the decision is likely based on something specific, unless my luck really was that bad.  Possibly the world seed?  I don't know.  *edit* Tested it and the very first one was swapped.  Eh, whatever. --Theothersteve7 20:51, 14 December 2011 (UTC)

I have had world seeds where the hallow spawns only in the Jungle. It made a few pearlstone blocks on the surface, but i could not find any below. In addition to this, it proved that Corruption can spread through mud blocks, but as far as i can tell the Hallow will not. I also tried putting hallow in a world not in hardmode, and it spread at roughly the same rate as the corruption. Neither corruption nor hallow was able to spread through a 3-block wide wall of dungeon bricks. Has anybody else tried putting hallow in a normal world? If so, on mine i saw a Chaos Elemental spawn. Has anybody else seen this?
 * Concerning the Chaos Elemental spawns, I looked at the code, and they can in fact, spawn on non-hardmode worlds. The only conditions are that you are in the rock layer, and that the tile they spawn on is Pearlsand or Pearlstone. They also will not appear if any town NPCs are around.--GauHelldragon 21:24, 14 December 2011 (UTC)

you sound like the hardmode production of hallow and corruption/crimsn are fully predictable, would anyone of you like to tell me how to predidct the preceise locations of the v formation these will be created in, i havent even started my airgap just because i dot know how to predict the size of the "v" preceise enough to make he airgaps whiout the hard mode corruption getting created on the wrong side of itcrackmore

Which spreads faster?
Does Corruption or Hallow spread faster than the other, or is it equal? ---Linkraft 21:50, 14 December 2011 (UTC)
 * They spread at the same rate. The initial deposit of corruption upon entering Hardmode overrides the initial deposit of the Hallow. --Theothersteve7 16:09, 15 December 2011 (UTC

Spontaneous Corruption Sieging my Home!
I recently came back to my home after a trip underground to find my jungle tree farm mostly corrupted and corruptors flying about. I can't figure out where the corruption came from. There was uncorrupted grass on the left and below, hallow on the right, and a clean dirt skybridge above. I haven't smashed any demon altars remotely recently, so I don't see how it could be a conversion from that. I'm pretty sure I couldn't have inadventently lead any corruptors over there...and even if I did, I was thousands of feet away both horizontally and vertically until I magic mirror'd back and found this, shouldn't that have despawned any enemies I left there?

Also, a bunch of my NPCs died around the same time, and I can't figure out how. Some of the NPCs were inside rooms with no exterior doors or windows, such that they would have needed to more horizontally one direction, up or down through wood platforms, and then back in the opposite direction in order to get outside (as far as I can recall, their normal wandering routine has always kept them on the same floor). I didn't find any monsters inside the house, and the walls facing the new corrupt area are made of grass but managed not to get infected, so I can only assume the corruptors weren't shooting in that direction.

But there were still at least 5 or so NPCs alive, which still seems like it should have been enough to stop the corruptors from spawning within a screen or two, right?

I'm so confused. I cleaned up the corruption and replaced the converted mud. (Guess I maybe should have taken screenshots first? Hindsight...)  But I would like to prevent something like this from happening again, and I just have no idea how it got there in the first place. Any ideas? --Manxome 10:15, 19 December 2011 (UTC)
 * That's really interesting. I haven't activated hardmode yet, still busy digging huge airgaps. I'll be sure to take "before" and "after" pics though. Have you tried exploring far away and returning to your house to see if it happened again? - Spinfx 12:58, 19 December 2011 (UTC)


 * Most NPC deaths I've had any more are caused by Wraiths. Also, was there any sand underneath your mud?  --Theothersteve7 15:11, 19 December 2011 (UTC)


 * I have actually discovered a second breakout of corruption, but it turned out to be due to a tiny lingering patch of underground corrupt grass that I missed the first time (just outside the range of purification powder from the surface). Other than that, nothing.
 * No sand in the vacinity; this was a normal forest biome before I flattened it and added a layer of mud for growing jungle trees. Wraiths are not a likely explanation for the NPC deaths, as most of the NPCs that died were not on the ground floor. --Manxome 22:19, 11 January 2012 (UTC)

Waterleaves on Ebonsand
I have a freshly corrupted desert and all the Waterleaf in it was uprooted. If someone would confirm it for me, I'd like to change the note that waterleaf will grow "normally" in corrupt deserts. --Theothersteve7 18:54, 19 December 2011 (UTC)


 * Is it possible that you uprooted it yourself somehow? My Ebonsand desert has no problems growing and keeping Waterleaf (and cacti). --24.67.67.238 04:57, 28 January 2012 (UTC)

Silt
I have the impression that silt can also be converted into ebon/pearlsand. Someone can confirm that?
 * The silt page claims this can only happen as part of the initial wave released when you first kill the Wall of Flesh, not as part of normal corruption spread. --Manxome 22:10, 11 January 2012 (UTC)

How does corruption spread?
Is the spreading area square or romboidal? Does it spread diagonally too? Or is it limited to 2 squares left and one down, 2 down and one left, 3 down, 1 right and 2 down and so on? Rampardos18 20:21, 14 June 2012 (UTC)

I wondered about this myself, and after conducting an experiment with one crimstone in a huge block of bare mud, the spread appears to be square. Pearlstone has also spread to stone blocks that were three spaces away diagonally. I will need to test to confirm, but I would assume ebonstone can spread similarly --137.151.175.64 19:39, 17 September 2014 (UTC)

Corruption spread vs. Steampunker spawn criteria
So the Steampunker can spawn in pre-Hardmode by defeating a mechanical boss. Defeating a mechanical boss in Hardmode also stops the spread of the Corruption, but I'm wondering if defeating a mech boss pre-Hardmode preemptively stops the Corruption spread, or if it's possible to have the spread and the Steampunker in the same world. Jimbo Jambo (talk) 02:10, 24 October 2013 (UTC)
 * It doesn't STOP the spread of corruption. It merely REDUCES/REVERTS the rate at which it spreads. From the page itself: "Killing a hardmode boss reverts the spread back to normal mode speed." Which means if you defeat a hardmode boss in a pre-hardmode world, nothing changes at all with regards to the spreading rate, since hardmode spread acceleration was never triggered in that world.


 * I apologize, I didn't think I had to clarify. In comparison to the Corruption's typical ungodly fast Hardmode spread, spreading through grass alone is basically no spread at all.
 * Anyway, yes, I have read the page, but everything on the wiki is limited by user experience, and that passage is not as specific as I'd like. It assumes that Hardmode has already been activated without mentioning what happens if it hasn't. Worlds clearly remember when a mech boss has been defeated since the Steampunker can spawn any time afterwards, not just the instant it happens, so it's possible the world simply checks to see whether or not it has happened before every spread event. Jimbo Jambo (talk) 03:26, 24 October 2013 (UTC)

The new Grass Walls can be Corrupted or made Crimson
Shortly after Hardmode started I painstakingly dug a 3-block quarantine trench from the surface of my Jungle to the Underworld to protect it from the approaching Crimson. Recently, I've found that the grass background walls in the Jungle and Forest biomes have been turning red (including Grass and Jungle walls placed by players). This worries me. I have no idea if background walls infected by the Crimson or Corruption can further infect foreground blocks. Is my Jungle still in danger? ... As well, were my quarantine measures even necessary or just an exercise in ignorant paranoia? Vardinator (talk) 01:37, 27 October 2013 (UTC)

this article needs a lot of tidying
"Corrupt grass can also displace normal and hallow grass, unless the grass has a Sunflower planted on it." iirc hallow grass and corruption cant converet each other, its a tie.

"Corrupt grass is still limited to the Surface Layer" my world is full of corrupt grass, almost to the cavern layer
 * Removed those, thanks.  Equazcion ( talk ) 10:59, 21 Jul 2014 (UTC)

Actually, corrupt and hallowed grass are capable of eating each other. Not the stone, not the ice, not the sand; just the grass. I once placed a strech of corrupt next to a stretch of hallow (I was trying to build a glass box with every biome in one space) and the corrupt grass started to convert the hallow, even converting the tree I planted on the Hallow. Thinking it was a glitch, I left and returned. While trying to taking a screenshot, the Hallow started to convert the Corruption, not only converting the tree back to pearlwood, but completely wiping out the corrupt grass.

Screenshots: 1 2 3 --SparkofLeaves (talk) 20:40, 17 September 2014 (UTC)

Non-Corruptible Blocks
There should be a table listing blocks that cannot be corrupted. Or, even better, a link to a page listing all of the Non-corruptible Blocks.
 * The list of non-corruptible blocks is much longer than the list of corruptible ones. Corruptible blocks are basically just dirt, stone, sand, mud, and ice. None of the 100+ other block types can be corrupted.  Equazcion ( talk ) 14:01, 3 Sep 2014 (UTC)

This information is in serious need of updating
Especially due to new rates applied to pre/post Plantera, major changes have been made to the potency of corruption and its ability to spread. The 3 block rule which is posted all over the wiki, this is no longer adequate here. A simple way to prove it is in the underworld, with vast stretches of open space where stone highways are a common strategy, to both fight the wall and farm souls later on when these blocks are converted.

What I did was build a jungle farm right beneath it, 4 blocks below the stone highway. The single layer of crimstone which formed above now converts the jungle grass to dirt/crimson as well, even with 3 blocks of empty space in between. It did not used to do this, especially with no thorns or vines to help it spread.

This can also be observed in the huge desert chasms which lead to the fossile caves, where walls are included in the spread mechanics as well, you can see the sand walls turn into corrupt walls. Not really sure what's happening in the underworld though, where there are no visible walls, so it seems the range has simply been increased.

World without corruption
So i have a world with crimson and DESERT corruption, but no actual corruption. Is there by any chance I can get it.BTW I am on hardmode, since I defeated the wall of flesh.
 * If you're on Hardmode, it should already be spreading throughout your entire world. As the page indicates, any forests will eventually become corrupt as grass and stone are converted, unless you take steps to stop its spread. There's nothing that can naturally cause chasms to form or deposit more shadow orbs into the world, but if you're mostly concerned about the spawns, they'll be there soon enough. Gearzein (talk) 16:55, 1 November 2015 (UTC)

One time, I created a world, and it had both Crimson, AND Corrupt. How did that happen?

2 Corruptions
I have a world on the PS3 edition that has 2 Corruptions, clearly separated by a Snow and a Forest biome. 1 is very irregular, with uneven terrain and merging Chasms that is between the mentioned Forest biome and a Jungle. The other Corruption is much more normal and takes up a chunk of the end of the Snow biome opposite the mentioned Forest, with normal Chasms. The world is not in Hardmode yet, so is this normal? Diamondcat6746 (talk) 23:08, 13 December 2017 (UTC)
 * Corruption Biomes are generated after the main surface of the land, so they will take some semblance of what was originally there. I have seen some pretty rugged world gen features. Having two Biomes of Corruption is not at all strange. Most likely, there is one on each half of the world. – ReedemtheD3ad!  ( talk ) 01:02, 14 December 2017 (UTC)
 * Also, on, Small Worlds are the minimum, which usually have two Corruptions —ϟ Awesome_Diamonds ϟ  「talk」 01:06, 14 December 2017 (UTC)

Can corruption spread through background walls?
Can corruption spread through background walls or does it need blocks to spread? 194.251.17.11 14:49, 7 April 2018 (UTC)
 * AFAIK walls can be converted, but cannot themselves convert anything. --MentalMouse42 (talk) 15:43, 7 April 2018 (UTC)
 * Requesting followup on this & some form of addition to the relevant pages. Thoughts: 1) Corrupted backwalls definitely exist.  2) Purification Powder doesn't seem to affect corrupted backwalls, but purifies the blocks in front.  (Determined by mining out the purified stone blocks & finding corrupted leaf wall behind 'em.)  3) I'd rather not have corrupted backwalls allow preexisting corruption to breach containment.
 * Thanks. 208.89.33.43 18:11, 12 August 2019 (UTC)
 * Powder may not purify them, but IIRC the Clentaminator does. And as I said last year, I don't think walls can actually spread the biomes, they just get corrupted by nearby blocks. --MentalMouse42 (talk) 23:09, 12 August 2019 (UTC)
 * Understood; nevertheless your discussion page comments are the only coverage I've seen (checked both evil biome pages, both underground pages, and all four talk pages. Did not check Hallow) of backwalls' (non-)effect on spreading biomes.  Would appreciate that getting covered in more detail on the biome mainpages.  Thanks for your time.  208.89.33.43 20:17, 14 August 2019 (UTC)
 * Unfortunately, I'm not a code-diver, and my current game isn't going to Hardmode for a while. So until someone with access to the code reports in, or someone sets up for experiments in a Hardmode world, this is what you have.  --MentalMouse42 (talk) 23:13, 14 August 2019 (UTC)
 * I have taken a look at the source code, and it appears walls are in fact capable of spreading, but only to other, natural purity walls. See Talk:Biome spread. --Rye Greenwood (talk) 04:14, 18 August 2019 (UTC)