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The Abyss biome, as viewed on the map in a large world.
If you were looking for something other than the Abyss biome, see Abyss (disambiguation).

Bestiary Abyss Layer 4.png "While there are many sightless crevasses in the deep sea, this one is a unique geological marvel." Bestiary Abyss Layer 4.png

The Abyss is an aquatic biome added by the Calamity Mod which spawns upon world creation. It is located under the Sulphurous Sea on the Dungeon side of the world through a chasm on the seafloor. It is extremely deep, dark, and perilous, filled with deadly enemies, which increase in strength as the biome grows deeper. Because many enemies in the Abyss are initially passive, only becoming hostile when hit or when in close proximity to the player, stealthiness should be greatly prioritized while exploring the biome.

The Abyss is divided into four distinct layers, each with a different set of tiles that generate and enemies that spawn.

  • The Sulphuric Depths form the entrance to the Abyss and are mostly safe, consisting of "islands" that generate in the middle and on the sides of the Abyss, with a few plants and decorations. No real danger is present in this layer, as it serves as a transition from the mostly peaceful Sulphurous Sea. The water in this layer has a Sulphuric Depths Waterteal-greenish color.
  • The Murky Waters is the first true exploration site of the Abyss. The islands on this layer have Ancient Treasure Chests containing either powerful late Pre-Hardmode weapons or useful items for further Abyss exploration. As defeating Skeletron is required to open and loot these chests, it is highly recommended to explore these layers after Skeletron has been defeated.
  • The Thermal Vents contains almost all of the most dangerous enemies in the Abyss, including the biome's mini-bosses. Layer 3's danger is comparable to layer 4, but is similar in structure to layer 2. unlike layer 2 however, it has a geothermal theme. It is recommended to explore this layer after Polterghast has been defeated. The water in this layer has a Thermal Vents Waterdark brown color.
  • The Void contains all the most dangerous enemies present in the biome, which include the biome's mini-bosses. Layer 4 is made of Voidstone and Voidstone Walls and is relatively open, with chunks of floor coming out of the walls, until it comes to a closing point. A Void Chest containing the Terminus can be found at the bottom of the Abyss. An Abyss Shell Fossil is also found at the very bottom of the Void. It is recommended to explore this layer after Polterghast has been defeated. The water in this layer has a Void Waterdark bluish color.

The first layer of the Abyss is mostly composed of Sulphurous Shale, with Hardened Sulphurous Sandstone Walls as a background. The second layer is mostly composed of Abyss Gravel and Abyss Gravel Walls. The third layer begins replacing Abyss Gravel with Pyre Mantle, Molten Pyre Mantle and Voidstone Walls, while the fourth layer is completely made out of Voidstone. Planty Mush and Scoria Ore can be found in the 2nd layer and Scoria Ore can be found in the 3rd layer. Several Pots are scattered around the islands, containing several useful drops. Different layers have their own decorational tiles, with some being functional or dropping items.


CharactersUnique TreasuresUnique DropsMusic

Layer 1:

Aquatic UrchinAquatic Urchin
Box JellyfishBox Jellyfish
Moray EelMoray Eel

Layer 1 and 2:

Toxic MinnowToxic Minnow

Layer 2:

Luminous CorvinaLuminous Corvina

Layer 2 and 3:


Layer 3:

Chaotic PufferChaotic Puffer
Devil FishDevil Fish
Giant SquidGiant Squid
Mirage JellyMirage Jelly

Layer 3 and 4:

Colossal SquidColossal Squid(Miniboss)
EidolistEidolist(in Hardmode)
Gulper EelGulper Eel

Layer 4:

Bobbit WormBobbit Worm
Eidolon WyrmEidolon Wyrm(Miniboss)
Reaper SharkReaper Shark(Miniboss)
Primordial WyrmPrimordial Wyrm(Hidden boss)
From Ancient Treasure Chests:
Anechoic PlatingAnechoic Plating
Ball O' FuguBall O' Fugu
Black AnurianBlack Anurian
Depths CharmDepths Charm
Herring StaffHerring Staff
Iron BootsIron Boots
Strange OrbStrange Orb
Torrential TearTorrential Tear

From Pots:

Abyssal TreasureAbyssal Treasure

From Shrine in Layer 4:


From Aquatic Urchins:

Urchin StingerUrchin Stinger

From Box Jellyfish:

Jellyfish NecklaceJellyfish Necklace

From Moray Eels:

Depth CrusherDepth Crusher

From Sulflounders, Cuttlefish and Reaper Sharks:

Anechoic CoatingAnechoic Coating

From Toxicatfish:

Diving HelmetDiving Helmet

From Cuttlefish and Colossal Squids:

Ink BombInk Bomb

From Box Jellyfish and Mirage Jellies
after defeating Skeletron:

Abyss ShockerAbyss Shocker

From Luminous Corvinas, Bloatfishes,
Eidolon Wyrms, Primordial Wyrm,
and Reaper Sharks:


From many Abyss enemies
after defeating Calamitas Clone:

Depth CellsDepth Cells

From Eidolists
after defeating Calamitas Clone:

Eidolon TabletEidolon Tablet

From Eidolists and Eidolon Wyrms
after defeating Plantera:


From Mirage Jellies:

Life JellyLife Jelly
Cleansing JellyCleansing Jelly
Vital JellyVital Jelly

From Devil Fish and Chaotic Puffers
after defeating Golem:

Scoria OreScoria Ore

From Colossal Squids:

Black InkBlack Ink

From Colossal Squids
after defeating Polterghast:

Calamari's LamentCalamari's Lament

From Bobbit Worm
after defeating Polterghast:

Bobbit HookBobbit Hook

From Eidolon Wyrms
after defeating Polterghast:

Eidolon StaffEidolon Staff

From Eidolon Wyrms
after defeating Polterghast
and from Primordial Wyrm:

Eidolic WailEidolic Wail
Soul EdgeSoul Edge

From Reaper Sharks
after defeating Polterghast:

Reaper ToothReaper Tooth
Deep Sea DumbbellDeep Sea Dumbbell

From Primordial Wyrm:

Halibut CannonHalibut Cannon

From terrain:

Sulphurous ShaleSulphurous Shale
Abyss GravelAbyss Gravel
Pyre MantlePyre Mantle
Molten Pyre MantleMolten Pyre Mantle
Scoria OreScoria Ore
Planty MushPlanty Mush
Abyss Shell FossilAbyss Shell Fossil
White PearlWhite Pearl
Pink PearlPink Pearl
Ancient Treasure ChestAncient Treasure Chest

From Fishing:

Abyssal AmuletAbyssal Amulet
Alluring BaitAlluring Bait
Planty MushPlanty Mush
Sulphurous CrateSulphurous Crate
Layer 1:
Music Box (Abyss - Layer 1)Music Box (Abyss - Layer 1)

Layer 2:

Music Box (Abyss - Layer 2)Music Box (Abyss - Layer 2)

Layer 3:

Music Box (Abyss - Layer 3)Music Box (Abyss - Layer 3)

Layer 4:

Music Box (Abyss - Layer 4)Music Box (Abyss - Layer 4)

Light Level

Without a sufficient level of light, the player's vision may be reduced (similarly to the Darkness debuff) or blackened completely (similarly to the Obstructed debuff), depending on how deep they've descended into the Abyss.

  • In Layer 1, the player's vision will be reduced unless they have a light level of 1 or higher.
  • In Layer 2, the player's vision will be blackened unless they have a light level of 1 or higher, and reduced unless they have a light level of 3 or higher.
  • In Layer 3, the player's vision will be blackened unless they have a light level of 3 or higher, and reduced unless they have a light level of 5 or higher.
  • In Layer 4, the player's vision will be blackened unless they have a light level of 5 or higher, and reduced unless they have a light level of 7 or higher.

The following items increase the player's light level. These values are cumulative, and stacking several of them at the same time is required for maximum vision in the Abyss.


The breath meter drains faster in the Abyss, with each deeper layer applying more severe breath loss. Players with zero breath in the Abyss will lose health far more rapidly than if they were drowning in normal water. Finally, the Crush Depth debuff is commonly inflicted by enemies in the Abyss and causes the player's breath to drain even quicker. These conditions make underwater breathing equipment a necessity for players wishing to explore the Abyss.

The first layer of the Abyss reduces the player's breath by 2 every tenth of a second, resulting in a net loss of 20 breath per second. Each layer beyond the first reduces the player's breath three times as quickly as the previous: the second layer takes away 60 breath per second, the third layer takes away 180, and the fourth takes away 540.

The Abyss ignores all items that normally grant permanent underwater breathing, such as the Gills Potion, Neptune's Shell, and the Ocean Crest. These items are still useful as they separately help reduce the breath loss the Abyss applies to the player.

Breath loss rate

The following items reduce how frequently the Abyss takes breath away from the player. These effects add together to create an overall delay multiplier that slows down the Abyss' breath loss:

  • Gills buff or Ocean Crest: +4
  • Any item which lets the player ignore water physics, as listed below: +5
  • The delay multiplier is capped at 50. The Abyss takes away breath DelayMultiplier + 1 times more slowly from the player.

    Breath loss amount

    The following items reduce the quantity of breath taken away by the Abyss. These effects do not multiply together. Rather, they add onto each other and create an overall percentage to reduce the Abyss' breath loss by:

    This percentage reduction is capped at 95%. At this cap, the Abyss removes 20 times less breath from the player.

    Drowning damage

    A player drowning in the Abyss takes extra damage in addition to the vanilla game's health drain from drowning. More precisely, the Abyss reduces the player's health instead of their breath if their breath meter is empty. With no relevant equipment, drowning in the Abyss deals an extra 30 damage per second in Layer 1, 60 damage per second in Layer 2, 120 damage per second in Layer 3, and 240 damage per second in Layer 4. This damage is reduced by 30 per second if the Depths Charm or Abyssal Diving Gear is equipped; this damage is further reduced by 60 damage per second if the Abyssal Diving Suit is equipped. The extra drowning damage dealt by the Abyss is slowed down by all items which reduce the rate of breath loss.

    Enemy Detection

    Abyss enemies have their own player detection system independent from enemy aggro, with a default detection radius and a reduced detection radius. Once an enemy has detected the player, it will not stop chasing them until it gets killed, moves too far from the player, or the player dies. Using either Anechoic Coating or Anechoic Plating will reduce enemy detection radii, these effects do not stack. Most enemies will detect the player regardless of distance if they are damaged.

    Enemy Detection Radius (tiles) Reduced Detection Radius (tiles)
    ViperfishViperfish 37.5 12.5
    Moray EelMoray Eel 18.75 15.625
    LaserfishLaserfish 25 12.5
    Giant SquidGiant Squid 31.25 18.75
    OarfishOarfish 15.625 9.375
    Bobbit WormBobbit Worm 12.5 3.125
    Gulper EelGulper Eel 37.5 12.5
    Colossal SquidColossal Squid 18.75 9.375
    Reaper SharkReaper Shark 31.25 18.75

    Additionally, enemy detection radii will be:


    Being in the Abyss decreases the player's defense, with more severe reductions occurring at the deeper levels. All of these defense reductions can be reduced to one-third effectiveness by equipping the Anechoic Plating or Abyssal Diving Suit:

    • Layer 1: -15 defense (-5 if wearing appropriate accessory)
    • Layer 2: -30 defense (-10 if wearing appropriate accessory)
    • Layer 3: -60 defense (-20 if wearing appropriate accessory)
    • Layer 4: -120 defense (-40 if wearing appropriate accessory)

    Unlike many defense reducing effects, the Abyss can reduce the player's defense below zero, causing them to take increased damage.


    Map Background Abyss Layer 1.png
    Layer 1 Map Background.
    Map Background Abyss Layers 2 and 3.png
    Layers 2 & 3 Bestiary and Map Background.
    Map Background Abyss Layer 4.png
    Layer 4 Bestiary and Map Background.
    • Drowning in the Abyss causes a custom death sound to play.
    • Fishing within the Abyss is possible, although it is very difficult and gives the same loot as the Sulphurous Sea.
    • Being in any layer of the Abyss below the first layer will disable natural life regen, much like the Bleeding debuff. This can be prevented by equipping the Depths Charm, Abyssal Diving Gear, or Abyssal Diving Suit.
      • Only the Abyssal Diving Suit will prevent bleeding in Layer 3. The bleeding effect cannot be prevented in Layer 4.
      • Equipping any of these accessories will also halve the amount of damage taken from running out of breath in the Abyss.
    • Attempting to use air pockets in the Abyss to regenerate air will instead deal very rapid damage to the player: a point of damage per tick (60 per second). This damage over time will stop if the player is at or below 100 health.
    • Lava and Honey buckets cannot be placed in water inside of the Abyss.
    • Sometimes in Small or Medium-sized worlds, and very rarely in Large worlds, the Abyss will generate over the Dungeon, usually resulting in Abyss Gravel blocks or Voidstone blocking some of the Dungeon's pathways.
    • It is possible to break holes into The Underworld from the Abyss. Doing so will drain the Abyss of water and may lead to the flooding of the entire Underworld.
    • Because Abyss Gravel leaks water naturally, should the Abyss be drained by accident, so long as said drain is plugged the Abyss will eventually fill back up over time.
    • The Abyss biome is defined by world position rather than the blocks present, meaning that entering any water beneath the world's Dungeon-side Ocean will cause the player to be considered as inside the Abyss, and all of the related effects will occur, even if the world was initially generated without Calamity installed. However, this also means that an artificial Abyss cannot be created by relocating Abyss Gravel or any other Abyss blocks.
      • If the world was generated without Calamity installed, most of the Abyss' unique physical loot can still be obtained from other sources. The chest items can be obtained by opening Sulphurous Crates, Planty Mush can be caught from Fishing, and Voidstone drops from several Abyss enemies.
    • All non-Boss enemies in the Abyss are inflicted with the Crush Depth debuff causing a loss of 1500 health per second regardless of progression.
      • This does not affect enemies that are immune to Crush Depth, including all of the enemies native to the Abyss.
    • It is possible to find Lime Kelp in the Abyss.
    • The water of the Abyss is naturally dark in color making it hard to see, but if a Water Fountain is placed in the Abyss the color changes to that fountain's water.
      • However, this does not prove very useful as the player's vision is still reduced by a sizable margin.


    • While the player can explore the entire biome even while in Pre-Hardmode, they are very unlikely to survive due to the intense pressure and strong enemies present in the deeper parts of the Abyss.
    • Having the Stat Meter is extremely helpful as it shows breath, defense loss and current light level.
    • The Aquatic Heart and the Shrimpy Truffle can prove very useful due to their increased mobility in water. The Cute Fishron mount is always wet and increases damage whereas the Aquatic Heart grants the Ocean's Blessing buff. Both additionally slow the rate of breath loss.
    • Selecting the Sea King's "Help" option grants the player the Amidias' Blessing buff for 10 minutes, providing unlimited breathing as long as they don't take more than 50 damage.
    • Bringing the Lifeform Analyzer can be beneficial, as it allows the player to detect the minibosses in advance and avoid confrontation more easily.
    • Do not use the Rod of Discord or Normality Relocator in the Abyss at any time. If the player is affected with Chaos State while in the Abyss, an incredibly powerful and hostile Primordial Wyrm will spawn regardless of their progression in the game.
    • Using torches that can be placed underwater, such as the Cursed Torch, Ichor Torch or Abyss Torch can help with the darkness of the abyss.
    • Abyss Vents and Thermal Vents (which can be found in the Murky Waters and Thermal Vents layers, respectively) release steam that deals very high damage and inflicts the powerful Burning debuff, which cannot be resisted by buffs or accessories that would otherwise grant immunity to it. It is highly recommended to destroy these vents when passing by them to make the player's current and future trips through the Abyss safer.
      • While these vents blend into their backgrounds and are barely even highlighed by the Dangersense and Omniscience Potions, they can still be identified by the steam they occasionally give off.
    • To restock on air while exploring the Abyss, the player can use a Portal Gun to quickly teleport between the surface and their current position. Set up a portal somewhere the player can breathe beforehand, and whenever they need air, place the second color portal.
    • The player could dig to the left/right of the Abyss to regenerate breath in a Underground biome to avoid the rapid health loss that occurs when air bubbles are used in the Abyss.


    • The theme that is heard while in the 1st layer of the Abyss is hesitation, which was composed by the artist Heart Plus Up!.
    • The theme that is heard while in the 2nd layer of the Abyss is Hadopelagic Pressure, which was composed by the artist DM DOKURO.
      • If the Calamity Music add-on mod is disabled, The Underworld's theme will play through all layers of the Abyss instead.
    • The theme that is heard while in the 3rd layer of the Abyss is R'LYEH, which was made by wiki editor RoverdriveX.
      • The name is a reference to the sunken city of R'lyeh, in H.P. Lovecraft's “The Call of Cthulhu”, which fits well with the Cthulhu themed bosses.
      • It was intended to be just a placeholder but was kept due to positive reception from the community.
    • The theme that is heard while in the 4th layer of the Abyss is void, which was also composed by the artist DM DOKURO.
    • Some of the creatures in the Abyss are based on the game Subnautica, though most are based on real-life ocean creatures.
    • If the player drowns in the Abyss, the death message will either appear as "<PlayerName> is food for the Wyrms.", "Oxygen failed to reach <PlayerName> from the depths of the Abyss.", or "<PlayerName> faded away, lost in the dark waters."
    • The Abyss generates under the Dungeon-side Ocean in order to prevent conflict with the Thorium Mod's Aquatic Depths biome, which always generates under the Jungle-side Ocean.
    • The Abyss and the Sulphurous Sea are comparable to the Pelagic zone, the way the ocean's layers are categorized, with the Sulphurous Sea being the Epipelagic Zone, the first layer of the abyss being the Mesopelagic Zone, the second layer being the Bathypelagic Zone, the third layer being the Abyssopelagic Zone, and the fourth and final one being the Hadopelagic Zone.
      • Hadopelagic Pressure does not play in the 4th layer even though it is considered the Hadopelagic Zone.


    These history sections are still a work-in-progress, and may not yet contain changes relevant to the current version of the Calamity Mod.
      • Revamped the biome:
        • It is wider and has new plants and features for each layer.
        • All four layers are much more distinct:
          • The Sulphuric Depths use Sulphurous Shale tiles, use the music from the Sulphurous Sea, and serve as a transition from the sea to the Abyss.
          • The Murky Waters are closer to the original Abyss, no longer have houses with Locked Shadow Chests and instead have Ancient Treasure Chests scattered around the layer, that are locked until after defeating Skeletron, and have identical loot. Some rocks around the layer can be broken for White Pearls and Pink Pearls.
          • The Thermal Vents use Pyre Mantle and Molten Pyre Mantle tiles, and will contain the majority of the Scoria Ore.
          • The Void now has chunks of floor coming out of the walls, making it much rougher. At the very bottom, an Abyss Shell Fossil can be found.
        • Lumenyl Crystals now grow further apart.
        • Its generation now clears Lava and Glowing Moss from the edge.
        • Added a lot of gen cleanup (tile sloping, removing single floating tiles, placed water in air pockets).
        • Changed the generation for the third layer's walls. It's now a much smoother transition into Voidstone Walls instead of just a mess of Abyss Gravel and Voidstone Walls, the actual tile dithering is the same.
      • Resprited Abyss Layers' Bestiary icons.
      • Added death sound for drowning in it.
      • Shortened Bestiary filters.
      • Guardian Golem, Jewel of Light, Magiluminescence, Pumpkin Scented Candle, and Ultrabright Helmet now increase its light level.
      • Fixed a specific position in the first layer that did not count as the Abyss.
      • Fixed Sulphuric Poisoning applying in it.
    • Introduced three custom map backgrounds for the Abyss layers.
      • Now has map backgrounds:
        • Layers 2 and 3 share a background with each other, whereas Layers 1 and 4 each use a unique background.
        • These are currently only viewable as bestiary backgrounds. However, as no enemies are exclusive to layer 1, its background is currently unviewable.
      • Light level is no longer affected by Death Mode.
    • No longer applies an amplified Crush Depth effect to enemies while in the biome.
    • Breath meter loss now only starts when entering the second layer of the biome, and instead uses the standard breath loss mechanic from vanilla Terraria.
      • Now generates wider.
      • Pots now solely drop Abyssal Treasure.
      • Fixed an issue that caused world generation to open into the Underworld.
      • Increased darkness level in Death Mode.
      • Pots can now drop Triumph Potions.
    • Bleeding effect now becomes more potent in each layer.
    • Changed generation so that it utilizes space more efficiently.
    • The player no longer has to be submerged in Water to count as being in the Abyss, however, they will now take large amounts of damage if out of Water while in the Abyss.
      • Now deeper in medium and large worlds.
      • The fourth layer now uses void as its theme.
    • Now transitions from Abyss Gravel to Voidstone in deeper layers, including the houses.
    • The third layer now uses R'LYEH as its theme.
      • Now uses Hadopelagic Pressure as its theme instead of R'LYEH.
      • Smoothened generation.
      • Pots now have a custom look when broken.
      • Fixed the player not dying when at negative health in the Abyss.
    • The tunnel between the Sulphurous Sea and it is now longer.