Invisibility

Invisibility is a property that prevents you from being seen by other monsters that lack the see invisible property. Monsters with the property cannot be seen normally by the player unless they have see invisible themselves, though they can be detected through other methods.

Effects

While invisible, the monster's glyph cannot be seen on the map unless the monster can be seen through another method, such as telepathy. If you bump into an invisible monster, their square will be marked with an I, and searching will also mark their locations this way; however, this is done before the monster takes action, meaning they will often move to another square after. Bumping into a peaceful invisible monster will anger it.

While you are invisible, monsters will have difficulty locating you, and attacking monsters take a -2 to-hit penalty; such monsters will attack the square they think you are located on. Invisibility has no effect on combat between monsters.

An invisible player will be prevented from entering shops by the shopkeeper. ("Invisible customers are not welcome!") The shopkeeper will also prevent invisible players from leaving.

Effects on other objects and properties

Invisibility prevents displacement from working on monsters that do not see invisible. You also cannot scare monsters by applying a mirror unless they can see invisible; additionally, mirrors and sources of reflection will not reflect Medusa's petrifying gaze.

While invisible, wearing a mummy wrapping will render you visible until it is taken off.

Sources

There are multiple methods of becoming invisible:

• You can become invisible by quaffing a potion of invisibility, zapping a wand of make invisible at themselves, or wearing a cloak of invisibility; monsters can also do the same, and the potion effect is always permanent for monsters. You can also wear (or eat) a ring of invisibility, which will auto-identify itself when you put it on unless you have invisibility from another source. Except for non-blessed potions, these items will make you invisible either permanently or until you remove them.

• The spell of invisibility and nonblessed potions of invisibility will grant you temporary invisibility for 31-45 (more) turns.

• The Orb of Detection, the Archeologist quest artifact, can be #invoked to toggle invisibility on or off if you do not already have the property.

• Eating stalker meat will stun you and turn you invisible for 50-149 (more) turns; if you are already invisible through other means, you will instead gain permanent invisibility and the see invisible intrinsic. Pets cannot gain invisibility from eating stalkers.

Monsters will make use of the wand and the potion, which is always permanent for them, and the disappear monster spell is a mage spell that renders its caster invisible. Tame and peaceful monsters will only use these if you can see invisible. Stalkers and black lights are always generated invisible.

Strategy

Invisibility has a number of perks

Fighting while invisible

Invisibility is a good evasive aid, usually resulting in hostile attackers missing more often unless you stay in one place; it is especially useful in the early game, where few monsters will have see invisible, and can aid in escape from unexpectedly powerful foes. This can also double as an offensive aid that allows you to keep targets off-balance while picking them off from a distance, e.g. with projectiles or polearms. As the game progresses, you will encounter monsters with see invisible, limiting its effectiveness (unless paired with something like displacement).

Since its passive gaze relies on you seeing it, a floating eye is not affected by a player's invisibility; however, turning the eye invisible instead will render the gaze ineffective unless you have see invisible, rendering it harmless and allowing you to attack it with impunity. Invisible floating eyes will also not paralyze pets that cannot see invisible; this is especially useful for pacifists.

Invisibility can actually be a disadvantage in certain scenarios: unicorns in particular cannot see invisible and will not know the player's location to keep a knight's jump away, meaning that hostile unicorns will close in unexpectedly and likely skewer an early character. Conversely, invisible players can safely approach co-aligned unicorns to throw their gems at, and cross-aligned ones will be easier to kill or pacify for a prepared character. Invisibility can also make controlling other monsters for various purposes difficult if they lack see invisible, e.g., luring soldiers into Castle trap doors or luring wraiths away from non-graveyard levels.

The mummy wrapping is a good cloak for any player who elects to remain invisible long-term and finds it necessary to become temporarily visible for scenarios such as this. Like any other piece of armor, be sure to verify the beatitude of a wrapping before trying it on. If you temporarily remove another worn cloak to use a wrapping for shopping, make sure to replace the cloak once you're done.

=Fighting invisible monsters

Invisible monsters can be annoying to deal with, and are especially aggravating if the base monster was already decently strong (e.g., a stalker). Searching can reveal their approximate location and help you take the fight to them, and you can also lure the monster down a narrow hallway to make it easier to target; monsters that drink cursed potions of invisibility will also "aggravate" you, revealing their location to you temporarily and allowing you to plan accordingly. Pets are not deterred by invisibility and can pick a monster off as it approaches; if the monster is a black light, however, it will likely explode and confuse them, causing them to potentially attack you in turn.

If you recently heard a zap prior to killing a monster, and the monster drops a wand that makes engravings vanish, it is most likely a wand of make invisible.

Invisibility and shops

Among one of the main disadvantages to invisibility is that it makes shopping a hassle - you will be barred from entering or leaving unless you make yourself visible, which is especially troublesome if the source was a cursed item or gave invisibility that was permanent. Most players should keep a mummy wrapping or two on hand in case they accidentally wear such a cursed item and cannot remove it, obtain invisibility that cannot be toggled, or else simply plan to shop while invisible; they can also try to teleport into and out of the shop.

Variants

SLASH'EM

In SLASH'EM, items can also be invisible as well, including the corpses of invisible monsters.

"You feel here an invisible <monster> corpse."