Alchemy is an IQ/Very Hard skill; there is no default. Much of the skill has to do with experience in watching, hearing, and feeling the magical reactions proceed.
Making Alchemical Items
Each time you spend a point in Alchemy or any alchemical Formula, you learn a new Formula. You can also derive a new Formula as a Downtime action. In game terms, every elixir is a Hard skill; most default to Alchemy-1. Your skill level with Formulas may never exceed base skill.
To create an elixir, an alchemist must expend a certain amount of money for materials and a certain amount of time. The elixir will be brewing 24 hours a day during that time, and must be attended by an alchemist at least eight hours daily. An alchemist cannot pay attention to two different processes at one time, but he may manufacture a multiple batch of an elixir, multiplying the cost for materials by the number of doses produced. This process is a Downtime action.
On a critical failure, make a second Alchemy (or Elixir) roll at -1 for each dose in the batch. If this roll is successful, disaster is averted. If he faills, roll 3d6 to see what happens:
- 3-5: Everyone within 100 yards suffers the effect of the elixir or its reverse; 50% chance of each.
- 6-9: Everyone within 10 yards suffers the effect of the elixir or its reverse, as above.
- 10-12: Explosion destroys lab; alchemist has time to flee.
- 13-15: Explosion destroys lab; alchemist takes 3d damage.
- 16-18: Explosion destroys lab; alchemist takes 6d damage!
Your Alchemical Laboratory
An alchemist relies upon his equipment to achieve good results. At the very least, successful alchemy demands some method for making fire and an ample supply of clean containers; under such circumstances, an alchemist suffers a -1 penalty (or worse) to his effective skill. Most characters living and working in a settlement can be assumed to have this basic equipment, provided their Wealth Stat is at least 5.
A +1/+2 Tool cannot be used for Alchemy Downtime actions, but a +2 Consumable kit can (even though it can't normally be used for other Downtime actions normally). You can also invest in your lab: for every 2 wealth you spend, you get a +1 to your effective Alchemy skill and Formulas when you can work in it full time. You also need a book, or collection of books, called a Formulary, in which to store your Formulas. If this book is lost or stolen, you can't make what was written in it until you get it back. However, if a Formula's skill level equals that of your Alchemy skill, then you have it memorized. You may copy a Formula from someone else's Formulary once per in-game day; this does not take up your Downtime action.
Detection and Analysis
An alchemist gets a roll against his Alchemy skill, based on Per, to recognize an elixir as an alchemical preparation when he sees it, or smells food or drink containing it. Acute Senses assist this roll as appropriate. Similarly, a mage gets an automatic roll of (Per + Magery) to recognize an elixir as magical when he first sees it. Being magical in nature, elixirs can be detected by any spell that detects magic. However, spells to analyze magic do not work on elixirs. Only an alchemist can analyze them.
An alchemist must roll against Alchemy to analyze an elixir. Analysis takes 4 hours; a critical failure causes effects as per the table above. He can reduce this time to 10 seconds if he tastes the elixir – but if he does, any failed roll means it affects him as though he had taken it all, if the effect is a bad one. On the other hand, a critical failure while tasting an elixir does not require a roll on the critical failure table; it’s hard to blow up your lab by simply tasting something.
If the elixir analyzed appears in the alchemist’s formularies, any success pinpoints the nature of the elixir; if it is an unfamiliar elixir, a normal success merely gives a vague indication of the elixir’s purpose, while a critical success reveals the precise effects of the elixir, though not its name.
An alchemist cannot identify magic as precisely as a mage. However, an alchemist can determine whether an object is enchanted by spending an hour on analysis and 10 Alchemical Supply, and making a roll against Alchemy-2. On a critical success, he gets some inkling of the enchantment’s purpose. On a critical failure, the item has been splashed with acid or knocked into a flame. Whether this is disastrous depends on the item.
Using Alchemical Items
All elixirs should be kept in sealed containers. They lose their power after varying times when mixed with other substances or exposed to air. Containers can be opened briefly and then closed again with no harm to the contents.
The method of use of an elixir depends on its form (see below). Multiple elixirs may be used at once, but multiple doses of the same elixir will be wasted except on very large creatures, which may require extra doses at the GM’s discretion. A new dose can be taken after the previous one wears off.
When an elixir lasts for a variable amount of time, the subject doesn’t know in advance how long it will last – the GM rolls secretly. The subject knows it is wearing off 5 minutes before it ends. The exception is the Elixir of Invisibility, which wears off without warning.
Alchemical Items
There are four physical forms of elixirs, each with different properties:
- Potion: Liquid form, taken by drinking. One dose of potion affects one man-sized creature instantly. Potions lose their power in a day if left open or mixed with other things. Potions take a Ready action to uncork, and two Ready actions to drink.
- Powder: Solid form. A powder must be eaten in food, or dissolved in drink, to be effective; it takes effect in 2d minutes. Powders can last a long time; there is only a 50% chance per year that a given powder loses its power while exposed to air. Powders mixed with food or drink last a month.
- Pastille: A thumbnail-sized tablet, kept in a sealed vial. It takes a Ready action to get it out. When lit (another Ready action, typically), it instantly flashes into flame and begins to fill an area 3 yards across and 8 feet high with smoke. Indoors, this smoke lingers about a minute; outdoors, it disperses within about 10 seconds. Anyone within the affected area suffers the elixir’s effects in 2d seconds. To avoid the smoke’s effects, hold your breath. An unburnt pastille lasts a month if exposed to air, but is destroyed instantly upon contact with water. The creation of elixirs in pastille form requires double the cost in Supply.
- Ointment: A cream or jelly. If touched, it sinks into the skin, taking immediate effect – a dose of ointment on a weapon or doorknob only affects the first person to touch it. Lasts a week if exposed to air; neutralized by water.
- Alchemical Arrow: (or bolt, etc.) An arrow with a tiny, concentrated dose in the tip that releases into its victim's blood when it does at least one point of damage. If the arrow misses its mark, it still impacts something eventually, so the elixir inside is wasted. However, reduce the Supply cost by 50%.
Alchemical Charms are like magic items. You can make an Alchemical Charm out of any Elixir that you have spent at least one point on; they do not default to the Alchemy skill. There are two different types, Amulets and Talismans. Only one Alchemical Charm can be worn at a time. Charms kept in your bag don't count as worn. If you own more than one Alchemical Charm, always clearly state which one you're wearing.
- Amulets are treated as always-on magic items. There is no “time to cast,” and they cost the user no energy. They affect the wearer at all times, whether the person knows what the amulet does or not. Only elixirs that protect or hinder the wearer can be made into amulets.
- Talismans work for only a limited time. When a talisman is used, its effects last as long as the corresponding elixir would. The talisman then becomes dormant and must “recharge" until the next day. The person who last used a talisman can recharge it by wearing it for several hours, so you can only recharge one talisman per day. If you own more than one talisman, please state in a Downtime post which one you are recharging. There is no “cost to cast” for a talisman – no energy is spent activating one. The wearer must will the talisman to have its particular effect – simply willing it to “Do something!” won’t work. Activating a Talisman is a Concentrate maneuver. No roll is required.
- Periapts consist of a small gem, carving, stone, etc. that hangs off of a thin cord, which is tied to a weapon. A Periapt functions just like a talisman, except it is not willed to activate. Instead, it activates automatically (no action) when the weapon it is attached to strikes a target and deals at least 1 point of damage (in the case of a missile weapon, the effect is conferred through the projectile). To recharge a periapt, you can untie it from the weapon and wear it around your neck. When a periapt is attached to a weapon that is in your hand, that counts as worn.
Magic Resistance
Anyone with the Magic Resistance advantage gets a resistance roll of HT+MR when dosed with any elixir – even a beneficial one. If he rolls HT+MR exactly, the potion takes half effect (the GM determines the details). If he rolls less than HT+MR, the potion has no effect!
Reading Elixir Formulas
You can find all of the alchemical formulas starting on page 214 of GURPS Magic. The image below shows how to use them with our Downtime rules. This example costs 100 Alchemical Supply to create, and will be finished once 250/75=3.33 => 4 Progress has been achieved. You can make this without putting points into this specific formula by rolling Alchemy-2 instead.