Clouds are temporary dungeon features which occupy tiles. They usually cause damage or status effects to anything which occupies the tiles they are in, though some of them do nothing more than block LOS. They come in a variety of elemental flavors, can be created in many different ways, and can be potent weapons if handled properly. Clouds will dissipate on their own in time, but some areas will perpetually generate new clouds.
Player-generated clouds cannot be placed outside of LOS and will dissipate instantly if the player no longer has line-of-effect to them (most often, this will happen when the player can no longer see the clouds, but clouds also dissipate if the player moves behind a transparent wall). Additionally, no clouds can be placed on tiles where a cloud already exists; players may make use of this by, for example, casting Freezing Cloud near themselves while standing in a cloud of smoke.
- 1 Cloud Varieties
- 1.1 Atmospheric
- 1.2 Opaque
- 1.3 Calcifying dust
- 1.4 Steam
- 1.5 Flame
- 1.6 Freezing vapour
- 1.7 Noxious fumes
- 1.8 Poison
- 1.9 Miasma
- 1.10 Spectral flames
- 1.11 Negative energy
- 1.12 Acidic fog
- 1.13 Blessed fire
- 1.14 Mutagenic fog
- 1.15 Seething Chaos
- 1.16 Rain
- 1.17 Thunder
- 1.18 Raging winds
- 2 History
Atmospheric clouds are merely decorative and have no other effect, though no other clouds may be generated on top of them. Several varieties of atmospheric clouds exist, such as sparse dust, thin mist, or magical condensation.
Atmospheric clouds are largely created by the dungeon level around you or as part of a vault; the Swamp, for example, constantly generates clouds of thin mist. Certain other effects may make atmospheric clouds, such as the clouds of dust left behind by jumping spiders or trails of magical condensation left in the wake of worshipers of Xom.
Opaque clouds partially block line of sight; your LOS stops after two opaque clouds in any direction. Other than potentially blocking your view, opaque clouds have no other effect. Like atmospheric clouds, there are multiple varieties of opaque clouds, including several colours of smoke, translocational energy, golden dust, salt, white fluffiness, and ink.
Opaque clouds are somewhat rarer than atmospheric clouds, but may still be generated by the dungeon or certain vaults (pools of lava and altars to Dithmenos commonly have black smoke around them). You can generate clouds of smoke by reading a scroll of fog, using the Cloak of the Thief, or with Dithmenos's Bleed Smoke trait. Any creature will leave behind a cloud of translocational energy when it blinks, teleports, or is banished. Followers in good standing with the Wu Jian Council create clouds of golden dust when using their Heavenly Storm ability. Multiple areas in the Desolation of Salt and Cloud Mages' Chambers constantly generate clouds of salt and white fluffiness, respectively, and krakens may release a cloud of ink when injured (do note that unlike other clouds, kraken ink only affects water tiles).
Clouds of calcifying dust also block LOS, but they are far more dangerous than mere smoke or fog. Any creature that stands in calcifying dust begins to petrify, gradually turning into a helpless statue for several turns. Fortunately, players are only affected by these clouds if they end their turn in them; if you move out of the clouds as soon as they appear, you'll be fine (though this may make it difficult to fight back, especially if you rely on melee combat). Alternatively, any form of petrification resistance (being a gargoyle, being in Statue, Shadow, or Wisp Form, Zin's Vitalisation) will make the clouds safe to stand in.
Catoblepae belch forth clouds of calcifying dust at their prey, affecting friend and foe alike (though they themselves are immune to the effects).
Any area that has lava exposed to water will emit an endless amount of steam. You can create steam yourself by using Fire Magic over water, Ice Magic over lava, or with a pale draconian's breath attack.
- Damage per turn: (2d16)/2 - 1 (affected by steam resistance and/or fire resistance)
Clouds of flame are tiles which have caught on fire, dealing fire damage to anything standing in them. Firing some Ice Magic spells (Throw Frost, Bolt of Cold) through them will put them out. Demonspawn with 2 ranks of fire-themed mutations (Ignite Blood and Hurl Hellfire) become immune to flame clouds, as does any player holding the unrandart great mace "Firestarter".
Clouds of flame can be created by using the spells Conjure Flame, Ignite Poison (when poison clouds are present), Ring of Flames, and Fire Storm, a wand of clouds, a red draconian's breath attack, being a demonspawn with Ignite Blood 3, being a worshiper of Qazlal, and by igniting bushes or trees with powerful Fire Magic.
- Damage per turn: 9 + (2d23)/2 to the player; 5 + (2d16)/2 to monsters (affected by fire resistance)
Smoldering embers are generated underneath users of the Conjure Flame spell; they do no damage, but will ignite into a proper cloud of flames after one turn. However, if any creature is standing on top of the embers at the end of the turn (incuding the caster!), the embers will be uselessly smothered. Alternatively, the caster may immediately recast the spell to bring the fire to life, but doing so will place them in a cloud of fire.
Spreading flames are a special type of flame cloud created when trees catch fire from powerful Fire Magic or bolts of lightning. They act much like regular flames, but periodically create new flames in tiles next to them; if any trees are in these tiles, they may also catch fire, continuing the cycle until the fires eventually burn out.
Freezing clouds are tiles filled with brutally cold mist. They function almost identically to flame clouds, except that they deal cold damage and can be dispersed with Fire Magic (Throw Flame, Fireball, Bolt of Fire, etc.). Demonspawn with 2 ranks of ice-themed mutations (Icemail and Passive Freeze) become immune to freezing vapour, as will any player that wields the artefact executioner's axe "Frostbite".
Freezing clouds can be created with a wand of clouds, the Freezing Cloud and Glaciate spells, by using powerful Ice Magic over a body of water, by destroying a simulacrum, or by worshiping Qazlal. Miscasting some Ice Magic spells can also create clouds of freezing vapour.
- Damage per turn: 9 + (2d23)/2 to the player; 5 + (2d16)/2 to monsters (affected by cold resistance)
Clouds of noxious fumes (also known as mephitic clouds) are composed of mildly toxic and foul-smelling gases. Anything caught in one takes minor poison damage and is confused for several turns; creatures with more HD are less likely to be confused.
- Damage per turn: 1d3 - 1 (poison resistance gives immunity to all effects)
Poison clouds are tiles filled with highly poisonous gas. Anything caught in one will take damage and be poisoned, though poison resistance renders creatures immune. For even more damage, use the Ignite Poison spell to immediately convert these into flame clouds!
Players can create a single, extremely short-lived cloud with the Poisonous Vapours spell, although some miscasts can also create them. Swamp dragons, gold dragons, enemy green draconians, and green deaths breathe these, as can player nagas with the appropriate mutation.
- Damage per turn: 1d10 - 1 (poison resistance gives immunity)
Clouds of miasma (also known as foul pestilence) extremely dangerous banks of corrupt fog. Anything caught in one will take damage, rot, and become slowed and poisoned. If you can create them, they are extremely useful in combat so long as you don't catch yourself by accident.
Miasma clouds appear in some vaults, including the undead version of Swamp:4. You can create them with the Corpse Rot spell or the Foul Stench demonspawn mutation, and death drakes and ushabtiu will breathe them at you.
- Damage per turn: 1d12 - 1 (rotting resistance gives complete immunity, poison resistance stops you from being poisoned, and stasis prevents you from being slowed; Zin's Vitalisation protects you from everything but the damage)
Spectral flames burn with the chill fires of undeath. They deal partially-irresistible negative energy damage (though the undead are entirely immune) and occasionally summon spectral things that immediately attack creatures hostile to their creator.
- Damage per turn: 3 + (2d15)/2 (partially affected by negative energy resistance; undead are immune)
Clouds of negative energy are charged with dangerous soul-sapping forces. They deal large amounts of negative energy damage to creatures unfortunate enough to be caught in them as well as inflicting the drained condition. Of course, creatures that are immune to the effects of negative energies (such as plants, demons, and the undead) may safely ignore these clouds. The player has to have three levels of negative energy resistance to be completely immune to clouds of negative energy.
- Damage per turn: 9 + (2d23)/2 to the player; 5 + (2d16)/2 to monsters (affected by negative energy resistance)
Acidic fog is a hideously dangerous type of cloud; made of corrosive acid, it swiftly dissolves anything caught in it, though monsters that resist acid are immune. Fortunately, these creatures are few and far between, making it an effective weapon virtually anywhere outside of the Slime Pits. Corrosion resistance gives the player immunity to these clouds.
- Damage per turn: 9 + (2d23)/2 to the player; 5 + (2d16)/2 (affected by corrosion resistance)
Clouds of blessed fire burn with holy, cleansing light. They are opaque and block LOS, and are particularly deadly to the forces of evil such as demons and the undead; more mundane mortals still burn, but to a lesser degree. Only creatures consecrated by or in service to the good gods are immune to their effects.
Clouds of blessed fire are extremely rare, only naturally appearing in a very few vaults. Certain powerful holy creatures may create blessed flames to hinder their foes, however.
- Damage per turn: 7 + (2d19)/2 to the player; 3 + 1d12 to monsters (affected by holy resistance)
Mutagenic fog is composed of raw, uncontrolled magic. Stepping into these clouds will inflict heavy magical contamination upon a player which, if left unchecked, will likely cause bad mutations and possibly even damaging explosions. Monsters which enter the clouds are instead polymorphed each turn they spend in the fog.
These clouds are usually only found in vaults. Cigotuvi's Fleshworks in particular has several rooms filled with mutagenic fog.
Formed from the unpredictable forces of pure chaos, clouds of seething chaos produce effects similar to being hit with a weapon of chaos on any creature that enters them.
Rain clouds will create water over time on their tiles. Solid ground becomes shallow water, and shallow water becomes deep water. However, this extra water is short-lived and will evaporate soon, returning the floor to its normal state. Creatures made entirely of fire such as fire elementals or efreet will also take damage from the rainfall.
Sky beasts may create rain when turning invisible or becoming visible again.
- Damage per turn: 1d9 - 1 (only applies to fiery monsters)
Thunder clouds are somewhat unusual in that they only occasionally deal damage. Every so often (on average once every three turns), lightning will strike the ground beneath a cloud of thunder, dealing lightning damage and making a great deal of noise. Much like rain clouds, thunder clouds produce enough rain to damage fiery creatures beneath them, though they never make enough to leave pools of water on the floor.
- Damage per turn: 1d9 - 1 (only applies to fiery monsters)
- Damage per lightning strike: 11 + 1d12 (affected by electricity resistance)
Clouds of raging winds are created by tornadoes, whether from a player casting the spell or the presence of an air elemental, twister, or diamond obelisk. They deal heavy physical damage to creatures caught in them (damage increases as creatures approach the eye of the storm) as well as lifting them into the air and moving them in a circle around the caster. Additionally, most tornadoes are capable of blowing down trees (though an air elemental's Vortex is too weak to do so).
- Damage per turn: (creatures with tornado resistance are immune)
- Prior to 0.15, clouds of mutagenic fog directly caused mutations rather than causing heavy magical contamination.
- Prior to 0.14, clouds could be placed outside of the caster's LOS and dissipated slower outside of LOS. 0.14 also added clouds of negative energy, thunder, and acid.
- 0.13 added spectral flames.