Potion

Potions are magical drinks. They are denoted by an exclamation mark, ! and weigh 20. Some of them are very useful, some can be deadly. The effects of potions can be carried by drinking them or breaking them onto somebody by throwing it at them. Some potions can also be mixed together to form new potions — that is called alchemy.

A Unicorn horn can be used to help in identifying potions.

Smoky and Milky Potions always have special effects.

Table of potions

Potion	Cost	Weight	Prob	Appearance
water (uncursed)	0	20	92	clear
booze	50	20	42	random
fruit juice	50	20	42	random
see invisible	50	20	42	random
sickness	50	20	42	random
confusion	100	20	42	random
extra healing	100	20	47	random
hallucination	100	20	40	random
healing	100	20	57	random
holy/unholy water	100	20	?	clear
restore ability	100	20	40	random
sleeping	100	20	42	random
blindness	150	20	40	random
gain energy	150	20	42	random
invisibility	150	20	40	random
monster detection	150	20	40	random
object detection	150	20	42	random
enlightenment	200	20	20	random
full healing	200	20	10	random
levitation	200	20	42	random
polymorph	200	20	10	random
speed	200	20	42	random
acid	250	20	10	random
oil	250	20	30	random
gain ability	300	20	42	random
gain level	300	20	20	random
paralysis	300	20	42	random

The table is divided into price groups. See price identification.

Damage

Fire and cold attacks can cause potions carried in your main inventory to boil or freeze and be destroyed. This does not happen to potions carried in a container, so it is generally advisable to carry potions that way when possible.

Potions boiled by fire attacks are vaporized, which can subject you to the effects of the vapors. Potions frozen by cold attacks will not release any vapors.

Dilution

Most potions will become diluted when they get wet, either through immersion in open water, or dipping into open water, a fountain, or another potion (in alchemy). Note that this will not happen when dipping into holy water or unholy water--those potions change the beatitude of the dipped item without actually getting it wet, and are consumed in the process. Hey, they're magic.

Diluted potions are listed as such in your inventory, and they will not stack with non-diluted potions. This can be a minor hassle if your intention is to bless a group of potions with holy water, or if you have no container and inventory slots are at a premium. But otherwise, diluted potions function largely as full-strength ones do. There are some exceptions, mostly minor, which include:

• A diluted potion of booze will not cure 1HP of damage, as a non-diluted one will.
• A diluted potion of see invisible will give somewhat different messages, though the effect is the same.
• A diluted potion of fruit juice gives half the nutrition of a non-diluted one.

If a diluted potion is diluted a second time, it will lose any blessed or cursed status, and become an uncursed potion of water. This is a vital step in the production of holy water, an activity that will occupy most characters to some extent for much of the game. Even otherwise useless or harmful potions become a vital resource when considered in this light.

This is NetHack, so naturally there are some exceptions to the above principles:

• A potion of acid will not dilute, but instead cause an explosion that does damage to the character. If your character dies as a result of this, the cause of death will be listed as "elementary chemistry." (Acid can be used as a weapon, a cure for stoning, or turned into water via cancellation.)
• A potion of water can not be diluted, which is not surprising, but this means that holy water and unholy water are also immune to dilution, as they are simply blessed or cursed potions of water, and losing beatitude is a consequence of dilution.
• Alchemy will not dilute an already-diluted potion. So it is safe to convert a potion of healing into a diluted potion of extra healing, and this into a diluted potion of full healing--this will not leave you with a very expensive potion of water.

Alchemy is a somewhat complicated process which has a few wrinkles of its own. Players are advised to study that article before alchemizing unless they enjoy picking imaginary shards of glass out of their faces.

Hitting and Being Hit

Potions may be wielded or thrown in combat, by you or by monsters against you. A monster has an 80% chance of taking 1 HP of damage when hit (but will not be killed by this); you receive 1 to 2 HP, and, of course, you can be killed this way. If you don't see the potion hit the monster, you will get the message "Crash!" Whoever is hit by a potion will be affected by the potion, but generally to a lesser extent than from quaffing it. However, a thrown potion has a chance to miss the target, in which case it will shatter without affecting the the target. When a potion shatters, it is possible for the vapors to affect the player, if standing in an adjacent square. For this reason, wielding a potion hand-to-hand can be riskier than thowing it from a distance, although in this case the potion will only shatter when it hits the monster. Circumstances might dictate the choice to throw vs. wield a potion, for instance, someone wearing a ring of free action and wielding a potion of paralysis would be able to reliably paralyze a non-resistant foe.

Pointless Ruminations

Potions, or rather the bottles they come in, are one of the more remarkable types of objects in the world of Nethack. Potion bottles are not watertight, because falling in water while carrying them dilutes them. And yet they don't ordinarily spill or leak, because you can carry them for tens of thousands of turns without any risk of this happening. The bottle, presumably, evaporates or shatters or otherwise is destroyed when the potion is drunk, or else it could be refilled at any fountain for a practically inexaustable supply of holy water. Perhaps it is the bottle that is magical, as much as or more than the colored liquid within.

External Links

• Potions and their direct effects in NetHack 3.4
• Potions, alchemy, and other miscellaneous properties in NetHack 3.4

Encyclopedia entry

POTABLE, n.  Suitable for drinking.  Water is said to be
potable; indeed, some declare it our natural beverage,
although even they find it palatable only when suffering
from the recurrent disorder known as thirst, for which it
is a medicine.  Upon nothing has so great and diligent
ingenuity been brought to bear in all ages and in all
countries, except the most uncivilized, as upon the
invention of substitutes for water.  To hold that this
general aversion to that liquid has no basis in the
preservative instinct of the race is to be unscientific --
and without science we are as the snakes and toads.
        [ The Devil's Dictionary, by Ambrose Bierce ]