Revised Alchemy rules for GURPS

So ... following a forum conversation on the relative inadequacy of the GURPS alchemical rules, I figured I should throw my own set up, based partly on the book rules, partly on Pyramid articles, and partly on my own notions about which holes needed to be filled.  This doesn't include the actual list of elixirs, which really would only be of use to GURPS players.  Enjoy!

"Can't brew Aqua Vitae to save my life, you said?"

The following rules supersede the ones in GURPS Magic.

General: An Alchemist knows, at startup, a number of elixirs equal to (Alchemy skill x 1.5); therefore, a character with Alchemy-12 knows 18 preparations to start.  At least half of these must be in one category of Elixir: Poisons, Combat, Common Preparations, Magical, Medical, Mental, Physical and Protective.  This is the Alchemist’s Primary category.  Outside of this, an Alchemist may learn any formula from any category for which he or she meets the prerequisites.  However, any formula with a penalty of -4 or more is treated as “restricted” and only available to Alchemists for whom that is a Primary category.

A starting character cannot know Alchemical Metals, nor any formula with a penalty of -5 or more.

Brewing:  To create an elixir, an Alchemist must expend a certain amount of money and time as listed in the elixir lists.  (If not otherwise stated, the default time to make an elixir is one week.)  The elixir will be brewing 24 hours a day during that time, and must be attended by an alchemist for at least eight hours daily.  This need not be the same alchemist throughout the process, but if more than one alchemist works on an elixir, the lowest-skill alchemist is responsible for making the final Skill roll.  If the elixir is in the Alchemist’s Primary category, it takes 10% less time to brew and requires one hour per day less time to oversee – thus, seven hours vs eight.  Elixirs can be made as:

Grenade: To be thrown at a target, requiring a nagateppo.  Only those elixirs specifically flagged with a (G) can be made into this form;
Ointment: To be rubbed on bare skin (or another target); can be stored in a jar, tube or any waterproof container;
Pastille: A thumb-sized pill that needs to be lit, and affects all who inhale its smoke.  Must be kept in a fire- and water-resistant container;
Potion: Drinkable liquid, stored in any waterproof container;
Powder: Can be blown at the target or put into food or drink to be consumed; kept in a small bag or jar.

The basic field setup for brewing is listed in the price lists at two sovereigns and 25 lbs (exclusive of ingredient costs), and gives a -2 penalty to skill.  In an emergency, a fire source, scoured jars and clean field expedient tools are possible, but at a -3 penalty to skill or worse.  Brewing outdoors – where wind, dust and other detritus can interfere – likewise is not a great idea.
               
Being a magical process, alchemy is affected by background mana.  Add +1 to effective Skill for brewing in a high mana area, and subtract -3 for brewing in a low mana area.  Brewing in a very high mana area is hideously dangerous, and a number of alchemists are trying to figure out what effects brewing on a Dragon Line † cause.  Consuming an elixir is unaffected by mana level, but elixirs do not work in no mana zones.

Modifiers: Since alchemy is an art, not a science, applications of the following are up to the GM’s whim of the moment, especially on what elixirs can be affected by these and by how much.

* An alchemist can only oversee one elixir at once, but can brew multiple doses of the same elixir, at -1 to the final Skill roll for each additional dose.  For each -1 additional penalty to the Skill roll and 10% increase in both production time and ingredient cost, the duration of the elixir is increased by 100%; for instance, taking a -3 Skill and +30% time and cost results in an elixir with quadruple duration.  Similar actions may (repeat, may) have a similar effect on the elixir’s effects other than duration.

* By taking extra brewing time, the odds of success are improved: for each additional +50% in brewing time and +5% of cost (keeping those fires and reagents coming, y’know), add +1 to effective Skill roll.

* One way to create an elixir in a short span of time is to make a less powerful version.  For every 10% by which either the brewing time or the required ingredients costs are reduced (up to a maximum of 80%), the value, duration and all effects of the elixir are reduced by 10% as well.  For instance, one could brew a dose of Phoenix’s Blood in just four days, changing the result from recovering 1d HT to recovering 1d-2 HT instead.

Learning New Formulae: The formularies to brew an elixir are esoteric, obscure knowledge costing at least a sovereign a pop, and much more for an entire Category.  An Alchemist should spend as many days studying a new formula as it takes to brew that elixir; until that time is taken, the Alchemist can brew out of the book, but it takes half again as long for the preparation.  

Improving Skill: The effective Skill of all preparations is increased if the player increases Alchemy skill.  Alternately, individual elixirs can be learned (and improved) as Hard Techniques.

Mastery: An Alchemist is said to have “mastered” a category of elixirs when he has learned a certain number in each.  Mastery reduces the time required to oversee a brewing by a hour (which stacks with the hour reduction for Primary elixirs), and is a prerequisite both for learning certain formulae and for learning Alchemical Metals.  The requirements for mastering a category are:

    Poisons: Thirteen preparations.
    Combat: All ten preparations below -4 in difficulty (e.g., all but Mighty Bull and Starcrystal)
    Common Preparations: Ten preparations.
    Magical: Twelve preparations below -4 in difficulty (e.g., leaving out Alkahest, Radiant Dawn, Ratri’s Balm, Rudra’s Cloak and Water of Hematite).
    Medical: Twelve preparations below -4 in difficulty (e.g., leaving out Aqua Vitae, Ratri’s Balm, Stimulant/Gold and Water of Tourmaline).
    Mental: Twelve preparations below -4 in difficulty (e.g., leaving out San Pirian’s Elixir and Water of Diamond).
    Physical: Twelve preparations below -4 in difficulty (e.g., leaving out Aqua Verti).
    Protective: All nine preparations below -4 in difficulty (e.g., all but Mighty Bull and Water of Pearl).

    Elixirs belonging to more than one category (such as Mighty Bull or Ratri’s Balm) count for both.   

Mage-Alchemists: The use of certain spells can aid with alchemy.  The Skill penalty for the formula is applied to the spell’s effective Skill.  In every such case, failure on the spell cast ruins the batch.  The following spells can assist Alchemy:

* Essential Spell: The use of spells like Essential Water, Essential Fire, Essential Wood and the like – if such high-grade reagents are reasonably necessary to the process – reduces the time to brew and the cost by 15%.

* Food spells: Distill reduces the time to brew by 10%; Mature reduces it by 5%.  Cook reduces the cost by 10%.

* Temporal spells: The use of time-manipulation spells reduces brewing time, but must be continually maintained for the subjective duration of the brewing, and where applicable, the Alchemist must remain inside the affected area for the requisite eight hours a day (however subjective).  The entirety of the alchemical lab must be inside the area; a Fine lab, for instance, takes up a minimum of two Areas.

* Mimicking spells: If the effects of a given elixir mimic a specific spell, successfully casting that spell once per day on the brewing setup results in a reduction of 10% on both time and cost.  For instance, casting Bravery aids in the creation of Conqueror’s Wine.  Spells that reasonably affect the equipment itself will not end well: casting Levitation on a batch of Levitational Salts, for instance.

Regardless of how many spells might apply, the grand total reduction in time or cost may never go below 80%.

Alchemical Miscellany:

* Not being a “killer GM” by inclination (I’m talking to you, AD&D Miscibility chart), there is no baleful consequences to drinking multiple elixirs of different types at once, above and beyond their base effects.  (Guzzling San Caellan’s Brew and Water of Tourmaline at the same time, for example, is more than somewhat counterproductive.)

* If they’re stored in reasonably secure containers and in reasonably stable environments, alchemicals last indefinitely.  An elixir in an uncorked vial can be recorked, likely with no adverse effects, if it wasn’t abused in the meantime.  There are no guarantees about what happens to alchemicals that are stored in the open – say, powders in a potpourri dish, or elixirs sitting on the hearth.

* Alchemists can analyze elixirs and magic items as per GURPS Magic, p. 212.

* Techniques: Batching (Hard, default Elixir+0, buys off penalty for multiple doses of the same elixir), Identify Elixir (Hard, default Alchemy+0), Identify Magical Item (Hard, default Alchemy-2)

† - "Dragon Lines" are ley lines.  The places where such lines intersect are High Mana zones, at least.  They've only appeared on my gameworld in the last two years.