# Chemistry set

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Name

chemistry set

Appearance

box of obscure-looking glass devices

Base price

500 zm

Weight

20

Material

glass

Monster use

Will not be used by monsters.

The chemistry set is a tool in NetHack: The Next Generation and SlashTHEM, which provides a new way to get specific potions that is analogous to making scrolls with the vanilla magic marker:

Each chemistry set has a number of charges, which in-game represent its stock of potion ingredients, and are consumed when the set is used to make a potion. Each potion type in the game has a specific ingredient cost (see below).
Like writing scrolls, making a potion requires a "blank" item—an empty bottle.
The beatitude of the resulting potion is the average of the beatitudes of the set and the bottle, the same way as with magic marker.
You can make potions you have not discovered yet, with a small chance of success.
Unlike writing scrolls, making potions requires knowledge of chemistry. Potions made by the player are "selfmade" and have a luck-dependent chance of being defective.
Note that a chemistry set is made up of fragile glassware, which can shatter easily if thrown or kicked.

Contents

1 Prerequisites

1.1 Spellbook of chemistry
1.2 Bottle

2 Potion cost
3 Failure
4 Selfmade potions
5 Charging
6 See also

Prerequisites
Spellbook of chemistry

spellbook of  +   chemistry   

Appearance

random

Base price

100 zm

Weight

50

Turns to read

10

Ink to write

5–9

Spell type

divination

Level

1

Power cost

5 Pw

Direction

non-directional

Before you can use a chemistry set with certainty, you need to be familiar with chemistry. This can be learned by successfully reading a spellbook of chemistry. As long as you have the chemistry "spell" in your repertoire, you can use chemistry sets. Note that this is not a functional spell, and attempting to cast it will only produce a funny message ("You call upon your chemical knowledge. Nothing happens.").
If you try to use a chemistry set without knowing the "chemistry" spell, you may get the message "Huh? You don't understand anything about such stuff!" and one charge on the chemistry set will be used up.
Trying to use a chemistry set without knowing chemistry will always fail in NHTNG. 

Bottle

(

Name

bottle

Appearance

bottle

Base price

5 zm

Weight

1

Material

glass

Monster use

Will not be used by monsters.

Before you can make a new potion, you must have an empty bottle to contain it. The first thing that happens when you use a chemistry set is that you will be prompted to select a container from your inventory.
Empty bottles can be found as randomly generated tools, but a much more common source of bottles is quaffing potions, which will sometimes leave behind the empty container. ("You are left with the empty bottle.") If the potion was taken from a stack, so a new inventory slot is needed for the bottle, but there is no room in your pack, the bottle will drop to the floor. Bottles acquired in this way are naturally uncursed, regardless of the BUC status of the original potion. 
Also, if you quaff a milky potion but no ghost appears, presumably due to extinction, you get to keep the empty bottle.
Dipping an empty bottle in a fountain or moat fills it with water, making a potion of water.

Potion cost

Potion

Charges

extra healing

3

ESP

3

gain ability

3

gain energy

3

invisibility

3

recovery

3

see invisible

3

speed

3

cyanide

4

extreme power

4

gain level

4

full healing

5

gain health

5

invulnerability

10

heroism

20

All other potions cost 2 charges by default.

Failure
If the chemistry set doesn't have enough charges to make your desired potion, the bottle will explode ("You seem to have made a mistake!") dealing 10 damage, or 25 if the chemistry set was cursed. Getting killed by such an explosion will give the report that you were killed by an "alchemic blast".
If you attempt to make a potion you have not yet discovered, you have a luck-weighted chance of succeeding; otherwise, the bottle will explode.

Selfmade potions
Potions made using chemistry sets are flagged "selfmade" (compare homemade tins) and can be defective. When you quaff one, there is a small chance that it will be "bad" (due to an error in the preparation) and possibly have harmful effects, poisoning you for up to 20 hit points OR making you nauseated. A death resulting from poisoning from a selfmade potion will be attributed to "bad chemical knowledge"; however, you will not lose any health if you have poison resistance.
The probability that a selfmade potion will be "bad" and the probability that quaffing it will have a negative effect are each luck-weighted, so the higher your luck, the less likely you are to suffer harmful effects from quaffing your own potions.

Charging
Like most tools, a chemistry set can be recharged an indefinite number of times. An uncursed scroll of charging adds 1-5 charges. A blessed scroll adds 1-10 charges. A cursed scroll sets the number of charges to zero, unless the chemistry set is blessed.
The maximum number of charges a chemistry set can have is 117. This may have something to do with the number of elements on the current periodic table (118).

See also
Alchemy