Invisible

Version 0.19: This article may not be up to date for the latest stable release of Crawl.

Invisible is a status effect which renders the target unseen except through magically enhanced vision or via other senses. It functions differently depending on whether it affects a player or a monster.

Player Version

An invisible player gets the following bonuses and penalties, assuming your victim cannot see or sense invisible:

• Anyone attacking you in melee incurs a 35% reduction to their to-hit number.
• Any of your melee victims who have shields have their blocking roll divided by three.
• You occasionally make tier-3 stabbing attacks, and sleeping or unaware monsters suffer a large penalty to detecting you through your stealth.
• Enemy ranged attacks have their to-hit number halved, and may target the wrong tile entirely.
• Monsters are less likely to use certain spells or abilities against you.
• There is a chance opponents who can't see invisible will break off their attack and resume wandering.
• You have a 60% chance of gaining a point of magic contamination when handle_time() is called.
• You can only dissipate magic contamination via "violent discharge" or the wrath of Sif Muna.
• +5 to all hunger costs.
• -5 to your melee to-hit number if you yourself cannot see invisible. Official justification: you can't see your weapon.

Sources

You can become invisible by:

• quaffing a potion of invisibility.
• casting the level 6 Hexes spell Invisibility on yourself.
• using the Evoke Invisibility ability granted by a cloak of invisibility or certain artifacts.
• zapping yourself with a wand of random effects (5.5% chance).
• Dithmenos' Shadow Form turns you into a shadow, granting intrinsic invisibility.

Regardless of source, player invisibility lasts for 14 + 1d(spell power) turns (max: 100 turns)

Strategy

The usefulness of being invisible is surprisingly limited. First off, acquiring it can be somewhat tricky. Potions are very finite, and gaining the skill necessary to cast a level 6 spell can be prohibitive for many builds. Even once it is easily castable, overuse generates magic contamination rapidly, putting you at risk of dangerous miscast effects and bad mutations. Finding items with evocable invisibility is the easiest way to gain unlimited access early on, but this is by no means guaranteed.

Also, the list of monsters capable of seeing or sensing invisible is unfortunately rather large, making the status effect completely useless against them (or worse than useless if you yourself can't see invisible). However, stealthy stabber characters can benefit from being invisible tremendously; it greatly enhances both your ability to go undetected around susceptible enemies and your damage output in melee with them thanks to the stabbing opportunities it provides. The trick lies in learning which enemies can and cannot see right through it.

Alternatively, consider learning the Dazzling Spray spell. This level 3 spell damages opponents and renders them dazzled, duplicating many of the advantages of invisibility with none of the drawbacks, and affecting many opponents that possess see invisible.

Comparing

• Potions have no chance of failure, but are of limited quantity.
• Evocable sources are able to be used with no training, but even with high Evocations will still end up with a noticeable failure rate and short duration.
• The spell requires heavy investment in Hexes and a hefty 6 mp per cast, but becomes very reliable and long lasting at high spellpower.

Evocable invisibility lets you end the effect early, if you have concerns about contamination.

Monster Version

Invisible monsters are very dangerous to a player who cannot see invisible. If you cannot see invisible, then in melee with invisible monsters:

• Your shield rolls are divided by three.
• You suffer a -10 penalty to your EV against their melee attacks
• You suffer a -6 penalty to your melee to-hit number against invisible monsters.

On top of that, invisible monsters cannot be seen either within your line of sight or on the map, and if you actually manage to guess which tile they're in and attack them, you receive significantly less information than normal (the monster is referred to as "it" rather than by its actual name).

Sources

Permanently invisible

These monsters are permanently, inherently invisible:

• x Unseen horror
• y Ghost moth
• W Shadow wraith
• 2 Lorocyproca

Casters of invisibility

Some spellcasting monsters can make themselves invisible:

• o Orc wizard
• O Ogre mage
• I Sky beast (by inherent ability, not a spell)
• p Shadow (by inherent ability, not a spell)
• e Deep elf soldier
• e Deep elf fighter
• e Deep elf knight
• e Deep elf mage
• e Deep elf conjurer
• L Lich
• L Ancient lich
• V Vampire (monster)
• V Vampire knight
• V Vampire mage
• R Rakshasa
• g Boggart
• p Necromancer (monster)
• p Wizard (monster)
• @ Sigmund
• o Blork the orc
• O Erolcha
• m Ilsuiw
• @ Kirke
• x Erica
• f Maurice
• L Boris
• @ Norris
• @ Frederick
• i The Enchantress
• & Gloorx Vloq

This effect has a finite duration, but the monster can always recast it after it has run out.

Potion or wand users

Monsters who know how to use magic items may use potions or wands of invisibility to make themselves invisible. This effect has a finite duration, but the monster can always reattempt it after it has run out.

Detecting invisible monsters

See invisible

If you have the see invisible intrinsic, invisible monsters gain no benefits against you. You can acquire this in the following ways:

• Wearing a ring, headgear, or artefact with the see invisible ego
• Having the Acute Vision mutation. Spriggans, vampires, nagas, and felids all have this mutation naturally.
• Having rank 3 of the Antennae mutation.
• Having rank 3 of the Eyeballs mutation.

Backlighting

Under some circumstances, a target may become backlit. This renders its invisibility ineffective, and actually makes it easier to hit than normal. Backlighting occurs whenever:

• You hit an invisible target with the Corona spell (must overcome magic resistance).
• You hit a substantial invisible target with Sticky Flame, unless it's standing in water (that immediately extinguishes the flames).
• An enemy enters your Halo aura.
• You suffer from significant amounts of magical contamination (yellow or worse).

Invisible monsters revealed as a disturbance

Certain less stealthy monsters, like orc wizards and sky beasts, will occasionally leave disturbances while invisible, represented by a white humanoid outline if playing in tiles or by the { glyph if playing in console. Additionally, all substantial invisible monsters, when passing through a cloud, are temporarily rendered visible in the same way. Should you examine the disturbance (with the x key), you will be able to determine the creature's identity. Thus anything the player can do to create clouds when an invisible creature is near will aid him in fixing that creature's location:

• Reading a scroll of fog or evoking the cloak of the Thief.
• Using Ice Magic in and over lava, creating steam clouds.
• Using Fire Magic in and over water, creating steam clouds.
• Using any persistent cloud-based magic: Poisonous Cloud, Mephitic Cloud, etc.
• Casting Ring of Flames.
• Fedhas Madash's Rain and Sunlight abilities.

Also, any non-flying invisible monster in shallow water is always visible as a disturbance.

Submerged monsters

Certain monsters have the ability to render themselves effectively invisible by submerging. However, this is a defensive maneuver only: they are always revealed if they become adjacent to, or if they attempt to attack, the player. None of the conventional methods described above for detecting actually invisible monsters work on submerged monsters:

• In deep water: crocodiles, baby alligators, alligators, swamp worms, sea snakes, electric eels
• In lava: lava worms, lava snakes, salamanders
• In clear tiles: trapdoor spiders, air elementals

History

Prior to 0.13, invisible monsters were immune to the effects of Olgreb's Toxic Radiance.