Unicorn horn

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( Unicorn horn.png
Name unicorn horn
Appearance unicorn horn
Damage vs. small 1d12
Damage vs. large 1d12
To-hit bonus +1
Weapon skill unicorn horn
Size two-handed
Base price 100 zm
Weight 20
Material bone

A unicorn horn (or unihorn) is an important tool for curing your adventurer. You can also wield a unicorn horn as a two-handed melee weapon doing d12 damage; it makes a great non-artifact weapon for roles who are not restricted in the "unicorn horn" skill. You can also use a unicorn horn to help identify potions. Further, it is a decent light-weight backup fighting monsters that may otherwise harm your main weapon.

Thus, a unicorn horn is an important part of almost any ascension kit.

For medical application

Cures from uncursed and blessed application

An uncursed or blessed unicorn horn can cure:

Sickness is normally fatal, and the unicorn horn is the easiest way to cure sickness (you might not have the right potion or spell, and you might not be able to safely pray). The other ailments, such as blindness and confusion, normally time out, but a unicorn horn removes them faster. Repeatedly apply the horn until you are completely cured.

Applying an uncursed unicorn horn will fix (d(2d2) - 1) ailments, whilst a blessed one can heal (d(2d4) - 1) ailments[1].

The approximate cumulative odds of curing a single ailment:[2] Each line in the list above counts as one trouble, except that each attribute counts as a separate ailment.


Attempts 1 2 3 4 5
Cures 64.6% 87.5% 95.638% 98.43% 99.44%


Attempts 1 2 3 4 5
Cures 77.4% 94.89% 98.85% 99.74% 99.94%

What it cannot cure

A unicorn horn cannot cure:

It also cannot:

In addition, if you have the sustain ability property, a unicorn horn cannot restore lost attribute points.


Message Meaning
"Nothing happens." You have no conditions the unicorn horn can fix.
"Nothing seems to happen." You have a condition that could be fixed, but it wasn't.
"This makes you feel great!" You had attribute points restored, and you have no other conditions.
"This makes you feel better!" You had attribute points restored, but you still have other conditions.

(Possibly something like wounded legs that the horn can't fix.)

"What a relief!" The unicorn horn cured you of food poisoning or illness.

Cursed unicorn horns

A cursed unicorn horn will cause, rather than cure, a myriad of status ailments. For this reason, you should not attempt to use a unicorn horn for healing if it was found in a bones pile, at least until you have dipped it in holy water or BUC tested it.

Never attempt to wield a unicorn horn of cursed or unknown BUC! As a two-handed weapon, it will weld to both of your hands and make your game significantly more difficult.


Message Meaning
"You feel deathly sick." You became ill; you have between 20 and (19+Con) turns left to live.
"You feel much worse / even worse". You were already ill; your turns to live have been reduced to 1/3 of their value.
"A cloud of darkness falls upon you". You were blinded.
"You suddenly feel confused." You became confused.
"You stagger..." You became stunned.
"Oh wow! Everything looks so cosmic!" You started hallucinating.
"You are unable to hear anything." You became deaf. This outcome is half as likely as the others.
Random attribute-loss message You lost one point from an attribute.


Because the negative effects from a cursed unicorn horn can be cured without too much trouble by a non-cursed one, cursed horns may be useful as a source of status afflictions. In particular, they are a reliable source of confusion that preserves the illiterate conduct (not relying on forgotten spells or a cursed scroll of confuse monster). This can be useful when throne farming, for example.

You can curse a horn without breaking any conducts by dipping it in a fountain and use-testing it to see if any negative effects happen (cursed horns always apply a negative effect).

Potion identification

Once you possess a (non-cursed) unicorn horn, you can use one to help identify potions. More detail at the potions article.

Some things to have in mind about dipping the horn into potions:

  1. Dipping a unicorn horn into a cursed potion of water will curse the horn. You shouldn't try it anyway, since potions of water are always clear in appearance.
  2. Potions of polymorph present a special problem: dipping a unicorn horn in one will polymorph the horn. This presents several considerations:
    1. You can dip a wand or spellbook of polymorph first – you'll get the message "nothing happens" if the potion is polymorph. A ring of polymorph will not have this effect but will polymorph instead.
    2. Players without a spare unicorn horn may want to dip junk items into un-ID'd potions. Dipping ammunition (such as arrows) has the added benefit of identifying potions of sickness, since they will poison the item.
    3. Players adhering to polypileless conduct will want to refrain from dipping anything but polymorph wands and spellbooks into potions until they have potions of polymorph identified. Polymorphing in this manner breaks the conduct.
    4. Conversely, players with spare unicorn horns may want to use potions of polymorph on unicorn horns: being magical tools, polymorph has a small chance of producing something useful, such as a magic marker.

As a weapon

Unicorn horn skill

Unicorn horn
Max Role

Only unicorn horns use the unicorn horn skill, and there are no artifact unihorns.

Even with the unskilled, a unicorn horn is a popular weapon against rust monsters and disenchanters. Be careful not to use it in presence of spellcasters, however, because it is two-handed.

Average damage calculation

The average damage calculations in the following table do not include bonuses from weapon skills, strength, or from using a blessed weapon against undead or demons.

Weapon Average damage
+0 unicorn horn \frac{1+12}{2}=\bold{6.5}
+7 unicorn horn \frac{1+12}{2}+7=\bold{13.5}

Obtaining a unicorn horn

There are a few ways to obtain a unicorn horn; for example, you can find one in a bones level. However, by far the most common method is to kill a unicorn and take its horn.

When you encounter a unicorn, you might encounter any of the three varieties: black unicorn, gray unicorn, and white unicorn (representing chaotic, neutral, and lawful alignment). A unicorn that matches your alignment will be peaceful; do not kill them (yourself at least) or you will incur a severe (-5) Luck penalty. Any other unicorn is hostile; if you can kill it, it will drop its horn.

(On a bones level, the hostile/peaceful status of unicorns may not follow the usual rule. The Luck penalty applies whenever you kill a unicorn of your own alignment, even if it was hostile. However, throwing gems, even worthless glasses, will calm it down.)

During your first encounter with a hostile unicorn, you will probably not be strong enough to fight it in melee; a unicorn is fast and can hit you multiple times per turn. Let your pet attack it, and hit with ranged attacks. If you lack speed, unicorns will usually avoid being in line with your character, but using ray-based attack wands you can hit the unicorn by reflecting rays off walls. When it dies, it is guaranteed to leave a corpse and a horn. If you can get to the corpse before your pet does, there is a chance that eating it will grant poison resistance.

Even if the unicorn is of the same alignment as you, there is no penalty to your character if your pet succeeds in killing the unicorn. If you have no pet and no unicorn horn, you may wish to kill a coaligned unicorn yourself: if so, it's a good idea to throw it some valuable gems beforehand to offset the Luck penalty for killing it. Even better, after killing the coaligned unicorn, zap it with a wand of undead turning and throw some more gems at it, completely offsetting the luck penalty. Note that a resurrected unicorn has only a 50% chance of dropping a second horn, the rest of the time its horn will crumble to dust.[3] Additionally, as of NetHack 3.6.0, any extra horns obtained from a revived unicorn will not be considered magical items for polymorphing purposes.[4]

Is it cursed?

A unicorn horn which you have obtained yourself by killing a unicorn will always be uncursed and +0, but if you found it on a bones pile, it is important to check if the horn is cursed. Test it with your pet, or drop it on an altar, or use some other method. (If you do the pet test, you should later drop it on an altar or identify it so you know the actual BUC status and can notice if it later becomes cursed.) A cursed unicorn horn will never cure anything, and can even cause harm; some use it to confuse themselves before reading scrolls or looting thrones. If your only unicorn horn is cursed, and you cannot fix it, you will want to kill another unicorn.

Bless your unicorn horn as soon as possible, both because a blessed unicorn horn is more reliable and because it provides extra protection against it becoming cursed later on. Consider wielding it during Prayer, as your god may bless a weapon as a boon. In SLASH'EM enchanting a unicorn horn also increases its effectiveness.

Save extra horns

As you kill more unicorns, you will obtain more of their horns. Save them in your stash or remember their locations so you can retrieve a spare. You might lose your horn, or something might polymorph your unicorn horn or make it cursed. You can also give them to intelligent pets.

If you have several spares, you might consider trying to polymorph some of them. As long as they did not come from a unicorn that was revived at least once, unicorn horns count as magical tools, which means they have a good chance to become a useful magic marker. However, polypiling many horns may generate a skeleton.

Unicorn horns and pets

Monsters can become confused or stunned (for monsters, hallucination is simply replaced with confusion[5]). In this state your pets will attack you. However, unlike truly hostile monsters they do not fear Elbereth, and you will still be penalized for killing them. They are also likely to be both better equipped and higher level than a normal monster of their type. In addition, while you might see a normal hostile monster coming; a black light can sneak up on you and confuse your pet, leaving you immediately adjacent to danger with no warning. Your pet might even be of a type you wouldn't normally encounter at your depth, e.g. an Archon or titan. Not to mention that having your pet attack you instead of any nearby enemies means your offensive power has been reduced. These factors combined can make an ailing pet quite dangerous.

Fortunately, intelligent handed pets will make use of a unicorn horn to cure ailments. A pet will not use a cursed unicorn horn,[6] but since pets won't pick up cursed items, and no items can be cursed while a pet is carrying them, this situation probably can't arise in vanilla. Both uncursed and blessed unicorn horns are guaranteed to work on the first try for pets.[7]

Drop a unicorn horn on the ground in front of your pet, the pet should eventually pick it up. Your pet may choose to wield the horn as a weapon, or they may simply hold it. Your pet will carry it around and use it to cure its ailments regardless.


From the d12 damage, and the fact that it's a two-handed weapon, it is implied that a unicorn horn is quite large.



SLASH'EM adds an artifact unicorn horn, Nighthorn. It is lawful and confers reflection when wielded. One obtains Nighthorn by killing Nightmare at the end of the Lawful Quest. More details at the respective articles.

SLASH'EM also changes the chances of curing ailments. Blessed horns try to fix all problems, each with the given probability, and uncursed horns try to fix a single problem, with the same probability.[8]

Enchantment Chance
0 or less 30%
1 40%
2 50%
3 60%
4 70%
5 80%
6 or more 90%

Slash'EM Extended

The same rules and numbers from SLASH'EM also apply to Slash'EM Extended but applying a unicorn horn carries a 1% risk of the horn crumbling to dust. Therefore, it's advisable to enchant it up to +6 if possible, reducing the amount of times it has to be used in order to cure an affliction, as every use can cause the horn to break, whether it did fix a status problem or not. However, lost attribute points don't always get restored. There is a risk of about 33% that the message "Damn! It didn't work!" appears, indicating that a lost attribute point is now lost permanently so the player has to get it back the hard way. This means that a potion of restore ability may be more than just dilution fodder now.

It's advisable to carry spare unicorn horns, especially if the character is relying on them as a melee weapon. Using a horn with lower enchantment to cure afflictions while swinging one with higher enchantment means that the lower horn will crumble first, so the character won't lose any of their offensive power, but a lower horn might not fix disease/stun/hallucination in time.


In UnNetHack, a unicorn horn does not restore lost attribute points.[9] As a result potion of restore ability and spellbook of restore ability are useful items.


In dNetHack, unicorn horns are one-handed weapons. As in UnNetHack, they do not restore lost attribute points.

Encyclopedia entry

See the encyclopedia entry for unicorn.


  1. src/apply.c in NetHack 3.6.0, line 1847
  2. http://www.steelypips.org/nethack/343/tool-343.html#unicorn_horn
  3. mon.c in NetHack 3.6.0, line 267
  4. src/zap.c in NetHack 3.6.0, line 1332
  5. src/mhitm.c in NetHack 3.6.0, line 1088: Black lights are the only source of hallucination that can affect monsters.
  6. src/muse.c in NetHack 3.6.0, line 291
  7. src/muse.c in NetHack 3.6.0, line 620
  8. http://www.statslab.cam.ac.uk/~eva/slashem/tools.html
  9. http://sourceforge.net/apps/trac/unnethack/wiki/Items