Blindness

Blindness is a property that appears in NetHack, and blocks the sight of a hero or monster. It is also a damage type, AD_BLND, used for the attacks of a few monsters.

The zen conduct consists of playing the entire game with a permanently blind hero.

Description

A hero or monster that is blind cannot see for the duration of the property - messages describing actions such as monster-versus-monster-combat that you cannot see are omitted or else significantly altered.

Intrinsic blindness, i.e. blindness that is not the result of a worn or wielded item or a lack of sight or eyes, is defined as "blinded" in youprop.h. The game records the number of turns that a hero is blinded. The following attacks have the AD_BLND damage type:

• The claw attack of a raven
• The explosion attack of a yellow light
• The gaze attack of an Archon

In addition to being hit by any of these attacks, the following circumstances and items can result in a hero being blinded:

• Quaffing a potion of blindness, being hit by a thrown potion of blindness or inhaling vapors from a broken potion of blindness
• Having a ray of lightning pass through their square
• Engraving with a wand of lightning
• Applying a wand of light
• Applying an expensive camera and selecting the hero via .
• Being hit by the blind or lightning monster spells
• The monster-summoning effect of a magic trap
• The blinding effect of sitting on a throne
• Applying a cursed unicorn horn
• The effect of eating rotten food, with a ³⁄₁₆
• One of the failure effects of reading a difficult spellbook
• Being inside a poison cloud while not breathless, nonliving or invulnerable

A hero that cannot currently see due to their form or a worn item is defined as "blind" in youprop.h. This form of blindness is considered separate from the above, and is "permanent" in that it will persist until the source of the blindness is removed. Blindness of this type occurs from the following sources:

• Putting on a blindfold or towel
• Polymorphing into a monster with no eyes

Blindness resistance blocks light-based sources of blindness, and being blinded will prevent blinding from most other sources, with exceptions including the potion of blindness. A blind hero cannot use gaze attacks, and is unaffected by gaze attacks that require the target to see its user.

Creamed

Being "creamed" is a subset of blindness that results from a substance over the hero's eyes physically restricting their vision. The game records the number of turns that a hero is creamed.

Sources of creaming increment the number of turns that the hero is creamed and blinded by the same amount, so its duration is always less than or equal to the number of turns that the hero is blinded - this also means that the "creamed" status will always time out first, e.g. a hero that is blinded for 100 turns, and 50 turns later becomes creamed for a duration of 20 turns, will be blinded for a total of 70 more turns; during the first 20 of those turns, they are considered creamed.

The following actions can result in a hero being creamed:

• Being hit by a thrown or wielded cream pie, or applying a cream pie
• Being hit by blinding venom
• Applying a cursed towel

Blind from birth

Playing a zen hero via the blind option makes them "blind from birth". This blindness persists across any forms that the hero polymorphs into and cannot be cured, though wearing The Eyes of the Overworld cures its effects and breaks the conduct - for more details on the effects of astral vision on blindness, see the section on Astral vision.

The following information pertains to an upcoming version (3.7.0). If this version is now released, please verify that it is still accurate, then update the page to incorporate this information.

Wearing The Eyes of the Overworld does not remove zen-blindness - it will still suppress its effects while worn, but taking them off will leave a zen hero blind again.

Blind monsters

Monster blindness is handled differently from a hero's blindness.

Monsters that have eyes can be blinded by most of the above means if they have eyes. A monster without eyes is intrinsically blind, and cannot be blinded by other means.

A blind monster will move and attack erratically, and suffers a to-hit penalty. Blinded monsters do not respect Elbereth if they would have normally, and cannot use any gaze attacks they possess.

Blind movement

When a blind hero is moving normally, or else using near look via : or picking up items via ,, they will automatically use their hands to feel for items on the ground. Touching the corpse of a cockatrice or chickatrice this way will petrify the hero unless they are wearing gloves. Safe-moving via m will ignore objects on the ground.

A blind hero moving onto a seemingly empty square with a monster on it will show the monster as I, anger them if they were peaceful, and use up a move without attacking even while safe-moving via m. Moving into a square with an I or warning symbol will cause the hero to automatically attack in that square's direction - safe-moving via m will function as normal if a monster is occupying the square, or move into the square normally if it is empty. A blind hero safe-moving with m into an unseen footrice without wielding anything or wearing gloves will turn to stone as well, unless the footrice's position is marked by the warning property.

It is still possible for a hero to sense their surroundings through other means while blind:

• Searching manually via s will use a move and attempt to reveal the location of adjacent, unseen monsters if there are any nearby - monsters detected this way have the square they occupied at the time of searching marked with a I. If searching this way does not detect a new unseen monster, it will reveal all squares adjacent to the hero, clearing any existing invisible monster markers on squares where none are present.
• A hero that has intrinsic or extrinsic telepathy can detect all non-mindless monsters on the level while blind, and interactions with these monsters are handled normally, both for normal movement and safe-moving via m.
• Monster detection granted via a blessed potion of monster detection, or from casting the detect monsters spell at Skilled or higher, lets the hero track all monsters on the level for the duration of the effect, and those monsters are handled normally for purposes of movement.
• Movement involving monsters highlighted via warning functions as normal, since it does not rely on the hero's sight.

Blindness and items

While blind, most unidentified objects are described only by object class (e.g. "a potion", "a ring", "a long sword" etc.), including artifacts - only amulets and comestibles are treated as "seen" while blind. A blind hero will always know the appearance of eggs that they lay, and a hero that starts the game blind (i.e. from birth) will know the appearance of their starting inventory, as well as that of their pet (which in practice only applies to zen Knights).

Poisoning and erosion status of weapons are still shown if the hero becomes blind, and erode-proofing and charges are only shown if formally identified, even if it was erode-proofed while blind. Any dilution in potions is only displayed if the hero knows that potion's appearance. A blind hero that polymorphs any known object, or else fully dilutes known potions or performs alchemy with them, will render them unseen.

A hero cannot name the object class of unidentified objects, and any individual names will not be displayed (though they will affect stacking and naming artifacts). Blind heroes can still hear monsters reading the label of a scroll or quaffing a potion, but will not auto-identify them since they cannot see the result.

Buying or selling something at a shop while blind will have the shopkeeper identify its appearance with the exception of items in containers, merchandise that was stolen, or items that are covered by a hero's credit if they teleport out without paying.

If a blind hero attacking with Vorpal Blade or The Tsurugi of Muramasa causes the beheading or bisection special attack to trigger, the artifact's appearance will be revealed. Eating one of a stack of tins while blind will identify the contents of remaining tins in that stack.

Curing blindness

"Creamed" blindness can be cured by using the #wipe extended command, applying a non-cursed towel or praying successfully.

Temporary blindness that is not from the hero's current form, a worn item, being "creamed", or the hero being born blind can be removed with the following actions:

• Apply a non-cursed unicorn horn
• Invoke the Staff of Aesculapius
• Eat a carrot
• Cast a spell of cure blindness or extra healing
• Drink a non-cursed potion of healing, any potion of extra healing, or any potion of full healing
• Pray successfully - this form of blindness is considered a minor trouble

If the hero is blind due to a worn towel or blindfold and it is not cursed, they can simply remove it - a cursed blindfold or towel will require uncursing in order to remove, and is considered a major trouble for prayer purposes. A hero that is polymorphed into an eyeless form and not blinded from any other source will regain sight upon changing into a form with eyes (including returning to normal form).

Astral vision

While astral vision does not cure blindness on its own, but The Eyes of the Overworld both grants the properties and suppresses blinding effects, allowing the hero to see in spite of it - they can view and interact with monsters in the sight radius as normal, and items seen within that radius are treated as though the hero had seen and handled them personally. As temporary blindness is still applied even while suppressed, it will time out as normal with different messages.

Strategy

Blindness can be fairly debilitating in the early stages of the game, especially if a magic trap blinds the hero and hems them in with several hostiles. This typically makes floating eyes a priority target for the telepathy their corpses grant - thankfully, a hero that can temporarily blind themselves "at will" can also handle floating eyes very easily. Unicorn horns are among the most accessible cures for blindness for any character: being blinded unexpectedly becomes a short and manageable nuisance at most, as long as the horn is kept non-cursed.

Navigating while blind

Moving normally while blind requires significant care, due to the massive amount of complications introduced:

• Nearby peacefuls and pets may end up hit if you attack blindly, since you cannot see if they stepped into any square previously occupied by a hostile (or worse, killed the hostile themselves in the pet's case).
  • Being blinded in Minetown or a shop can result in a swift and unceremonious death at the hands of a shopkeeper or the Watch.
• Allowing hostile monsters to attack the blinded character first is incredibly risky - even if you attack the specific square you were hit from, the monster may have be fast enough to move away after attacking; at best, this results in a wasted turn attacking the I where they previously were.
• Levels with cockatrices have a long-term threat of instadeath: if one is killed and leaves a corpse, touching it without gloves while feeling around for objects will immediately render the hero a statue.
• The bloodthirsty Stormbringer is made even more dangerous to wield than usual.

A stethoscope can be applied for free once per turn to determine if something is in your path and it is unsafe to move there. In rare cases, chatting is useful to test for non-silent monsters, since it does not use a turn if you get no answer.

Telepathy and warning are the best properties to have in case you are blinded, since warning complements telepathy by revealing the positions of most mindless monsters - while even these properties combined will not reveal all possible monsters, the few mindless monsters that are not revealed by warning are generally not a threat at most points where you have access to both. (Further corner cases stem from hiders, mimics, Stormbringer, F, and deactivating safe_pet.)

Reading a scroll of magic mapping whose label or identity is known, or else casting the magic mapping spell, will reveal the layout of the entire level, which can be a time saver and even a life-saver in some circumstances.

Avoiding blindness

For the property that blocks blindness from certain sources, see Blindness resistance.

On top of the listed means of curing blindness, there are also ways to prevent some or all sources of blindness:

• Wielding Sunsword protects the wielder from light-based sources of blindness, including yellow lights, magic traps, and wands of lightning.
• Wearing a blindfold or towel can protect from blinding gazes and some other sources, such as blinding attacks - it will not prevent blindness from quaffed or thrown potions, however.
• As explained above, astral vision granted from The Eyes of the Overworld circumvents blindness.

Discovering objects

In addition to the listed forms of identifying items while blind above, there are other methods to identify objects while blind which are non-exhaustively listed below:

• Formally identifying objects via the scroll of identify or spell of identify will reveal all relevant information about them.
• A blessed potion of object detection reveals the appearance of all objects on the current dungeon level as if the hero had personally handled them, recursively including the contents of containers.
• Zapping a wand of probing will grant non-recursive knowledge of any objects in the direction it is zapped at, including the contents of containers and the inventory and identity of any monsters in its path at the time, and a hero that zaps it at themselves can see their inventory.
• You can dip items in holy/unholy water when blind, allowing you to learn their beatitude.
• Your quest leader will identify your own quest artifact and the real Amulet of Yendor for you. Additionally, the crowning gift you would receive if neutral or chaotic is made "seen" if you are already holding it.

History

Blindness as a status property exists in Hack 1.21 and Hack for PDP-11, which are based on Jay Fenlason's Hack, and also appears in Hack 1.0.

Messages

Pardon me, <foo>.

You moved with m into a pet either displayed as I or properly seen.

You move right into <foo>.

You moved with m into a non-tame monster that was either either displayed as I or properly seen.

Wait! There's something there you can't see!

You moved onto a seemingly empty square. This does not attack whatever was on that square, but does anger them if they were peaceful.

References

This page may need to be updated for the current version of NetHack.

It may contain text specific to NetHack 3.6.1. Information on this page may be out of date.

Editors: After reviewing this page and making necessary edits, please change the {{nethack-361}} tag to the current version's tag or {{noversion}} as appropriate.