Biome Modifiers are applied to some of the generated biomes randomly according to the world seed. These modifiers are presented with a flavor text message indicating which one is active after the Entered <Biome> notification message, accompanied by a decorative border for the message matching the biome modifier. For example, the Humid modifier's message is decorated with water droplets. Note that biomes that do not announce themselves (for example, the lava lake) may still have preset modifiers.
Some biomes will generate with a modifier by default, such as the Fungal Caverns which usually has Humid and the Desert which always has Hot. Any of the main biomes can randomly get one of the modifiers listed below, which may override the default modifier if that biome has one.
Each of the main biomes has a 10% chance to be generated with a modifier, with two exceptions:
When a biome succeeds the initial modifier chance roll, each of the modifiers have a probability value that affects the likelihood of that specific modifier being chosen.
The Mountain Hall (tutorial area at the very entrance to the Mountain and the Mines) will always receive the same biome modifier as the Mines, unless the modifier is not applicable for the Hall itself, as noted in the table below.
Some biomes have default modifiers which will be used if no other biome modifier is selected for them, such as the Fungal Caverns which is generated with the Moist modifier by default.
Holy Mountain areas never receive biome modifiers.
|Moist / Humid||"The air feels extremely humid"||Creatures (including the player) tend to be slightly wet.
Projectile speed is decreased slightly, and certain spells may curve their trajectory downwards akin to being underwater, or disappear prematurely.
It is harder to set flammable materials such as wood on fire, and any fire spreads slowly/gets quickly extinguished.
|0.7||This is the default modifier for Fungal Caverns.|
|Darkness / Fog of War||"A mysterious darkness lingers around this place"||Areas that are no longer in your field of vision become dark again after a short period of time.||1||Cannot appear in Mountain Hall. Always appears in Lukki Lair.|
|Heavy / High Gravity||"The air feels heavy..."||Projectiles and most entities get higher gravity||0.5|
|Light / Low Gravity||"The air feels light"||Projectiles and most entities get lower gravity||0.5|
|Ionized / Conductive||"The air smells ionized"||Various electricity-based hazards appear throughout the biome, such as laser cubes and electric emitters, and Sähkiö will sometimes be spawned. Additionally, all materials in the biome become conductive to electricity.||0.2||Cannot appear in Mountain Hall.|
|Freezing||"The air feels freezing"||Grass and moss are replaced with snow, freezable liquids will freeze over time on contact with the air, and a faint bluish color grade is applied to the area.||0||This modifier never generates randomly, and is instead applied to specific biomes by default, such as the Snowy Depths, and Hiisi Base. It is always applied to the surface Snowy Wasteland, and to the Frozen Vault.|
|Hot||"The air feels hot"||Any very flammable materials such as barren soil will burn if exposed to air. Open pools of water slowly evaporate.
In underground biomes, there are barrels filled with water scattered throughout the biome.
|0.6||This modifier is always applied to the surface Desert, and cannot appear in Mountain Hall.|
|Lucrative / Gold Veins||"You sense lucrative opportunities"||An increased number of gold veins spawn throughout the biome, with many of the gold veins being exposed. Biomes that previously had no gold veins will suddenly spawn with parts of their regular ground material becoming gold veins instead. This modifier has different ranges of effect depending on the host biome:
||0.01||Cannot appear in Hiisi Base.|
|Extremely Lucrative / Super Gold Veins||"You sense extremely lucrative opportunities"||In Snowy Depths, a moderate amount of gold veins are generated within the ground, very similar to the normal Lucrative modifier. In the other biomes it can generate in, their naturally more rare chance to spawn gold is modified so that gold is one of the common materials, spawning approximately the same amount as materials like ground or rock.||0.00025||Can only appear in Mines, Collapsed Mines, Coal Pits, and Snowy Depths.|
|Wet Soil / Plant Infested||"It smells like wet soil after rain"||Features from the Underground Jungle biome are present such as the dark variant of swamp liquid, patches of grass, hanging vines, and growing vines which will create small purple fruits that can be popped to release poison and start fires.||1||Cannot appear in Snowy Depths, Hiisi Base, Underground Jungle (which naturally has parts of this behaviour already), and Mountain Hall.|
|Cozy / Furnished||"It feels cozy in here"||Various pieces of furniture appear throughout the biome, and Mimics are added into the biome monster spawn pool. Mimics typically only spawn in place of a chest, but may spawn in a larger variety of places with this modifier.||0.5||Cannot appear in Mountain Hall.|
|Wary / Booby Trapped||"You feel wary"||Various proximity landmines like those of the Hiisi Mine Thrower appear throughout the biome.||0.75||Cannot appear in Mountain Hall.|
|Roomy / Perforated||"This place feels roomy"||Biome generates with a greater amount of open space, and tentacle/worm holes appear through the terrain. Small and medium-size worms become common, and giant worms may sometimes spawn.||0.75||Cannot appear in The Vault, Frozen Vault, Temple of the Art, or Snowy Depths.|
|Spooky / Haunted||"The hairs in the back of your head stands up"||Some enemies will spawn with some little ghosts which attack the player with spark bolts. Gravestones also appear occasionally throughout the biome.||0.5||Cannot appear in Mountain Hall.|
|Gravity Fields||"You feel an invisible force pushing and pulling you."||There are white gravity circles and red anti-gravity circles that pull and push slightly on projectiles scattered throughout the biome.||0.3||Cannot appear in Mountain Hall.|
|Fungal||"The air is filled with fungus spores"||There are some Laahustussieni and Möykky enemies around, as well as mossy/swampy water and the occasional buoyant blue fungus pods. The color grade is shifted to a greenish hue, with a hazy look to the air.||0.5||Cannot appear in Mountain Hall, Snowy Depths, Hiisi Base, and Fungal Caverns (which has these features naturally anyway).|
|Flooded||"Where did all this water come from?"||There are numerous leaky pipes scattered throughout the level, which drip water. The biome has a distinctly gloomy, vaguely bluish tint. Additional pockets of water spawn in the terrain, and Märkiäinen can spawn more commonly.||0.75||Cannot appear in Mountain Hall, Underground Jungle, Snowy Depths, and Temple of the Art.|
|Gas Flooded||"There’s a smell of gas in the air"||The biome will have a slightly green hue. Pipes releasing flammable gas are frequent, acid themed enemies become more common. Shooting the pipes will release acid.||0.5||Cannot appear in Mountain Hall, Coal Pits, Snowy Depths, Hiisi Base, The Vault, or Temple of the Art.|
|Shielded||"This place feels exceptionally secure"||Some enemies spawn with shields and numerous static shield generators appear throughout the biome.||0.1||Cannot appear in Mountain Hall, Coal Pits, and Snowy Depths.|
|Protection Fields||"Everything is glowing in a mysterious light...!"||There are circles of invulnerability scattered throughout the biome.||0.2||Requires completing part of the Uusi Aurinko questline.|
|Gloomy||"It feels gloomy in here"||The biome is dark with only immediate surroundings getting slowly illuminated.||0||Always and only appears in Magical Temple, Wizards' Den, and Dark Chest room.|
|Ominous||"There's an ominous atmosphere here...!"||There are unstable orbs scattered throughout the biome. Touching them will inflict damage and spawn a Giga Black Hole.||0.2||Requires completing part of the Uusi Aurinko questline.|
|Invisibility||"You suddenly have trouble focusing your eyes..."||Spawns invisibility machines which apply invisibility to nearby enemies periodically||0.1||Cannot appear in Mountain Hall or Mines|
|Wormy||"You hear creepy crawling everywhere!"||The worms Pikkumato, Mato, and Jättimato spawn more often. This is similar to the "Roomy" modifier, but doesn't pre-create any worm tunnels.||0.05||Cannot appear in Mountain Hall or Mines|