Here is my alchemy system, designed in line with my previous post on alchemy.
It uses the following resources:
Gavin Norman of City of Iron's Theorems and Thaumaturgy (Buy a printed copy here)
Jack Shear of Tales of the Grotesque and Dungeonesque's Tales of the Grotesque and Dungeonesque Compendium Vol. 1 (Buy a printed copy here)
Eric Jensen of Wampus Country's Arcane Abecediary (No print copy currently available)
Benjamin David of A Rod of Lordly Might's Skills: The Middle Road system
Blacky the Blackball of Gratis Games's Dark Dungeons (Buy a printed copy here)
This list of potion qualities I made up.
This system does not have a list for generating ingredients of potions. You can use this resource from Wizardawn if you don't have your own preferred list, or are not having your PCs generate them actively by harvesting things.
As per the Necrocarcerus house rules, we use Dark Dungeons skill-categories with Middle Road levels (So a PC has the Arcane Lore skill from Dark Dungeons at unskilled, skilled, expert or master levels, and tries to roll above a 5 for a success on whatever die type their skill allows). Potions are made with the Arcane Lore skill. Potions are always one use.
Note on terminology: "Consume" means activating something and using it up so it can't be used again. "Expend" means using something up without activating it. "Formula" means a recipe for creating a potion. "Potion" means the physical object itself.
Potion and Formula Qualities:
Potions and formulas have the following potential categories of qualities: Effects, Proper Consumption, Ingredients. Not all potions or formulas have all categories of qualities automatically, and not all potions or formulas have multiple entries for each quality.
Potions and formulas typically have an effective level of the minimum spellcaster level required to cast the spell, if their effect requires an effective level.
Once a formula's qualities are discovered / defined, the same combination of ingredients will generate them again. Potions may be ingredients in other potions and formulas.
Use the procedures from Procedural Metapharmacology to determine what different combinations of ingredients do.
Alchemical Laboratories and Testing:
Each Arcane Lore test outside of a lab costs nothing and takes 1 turn.
Each Arcane Lore test in a laboratory costs 1000gp and takes 1 week.
Tests in the field may be done sequentially. Tests in laboratories may be done simultaneously by different PCs.
An alchemical laboratory costs 5,000gp one-time. The 1000gp costs takes in upkeep, resupply and maintenance of the lab.
Consuming Potions:
If a PC knows the Proper Consumption method to use a potion and is able to do so, they may consume the potion and activate its Effect.
If a PC does not know the Proper Consumption method to use a potion, they may consume the potion but must roll on the Side Effects table.
Examining Potions:
A successful Arcane Lore test outside an alchemical lab will reveal one quality of the potion from any category of the PC's choice without consuming or expending the potion.
A failed Arcane Lore test outside an alchemical lab forces a PC to immediately decide whether to consume or expend the potion(s) involved. This counts as consuming the potion without knowing the Proper Consumption method.
A successful Arcane Lore test in a laboratory will expend a potion and generate a formula with Effects, Proper Consumption, Ingredients.
A failed Arcane Lore test in a laboratory will expend the potion and reveal nothing.
Creating Potions:
Creating potions can only be done in a laboratory.
1) Two ingredients without a corresponding formula are combined and consumed, and an Arcane Lore test is made.
On a success, the PC randomly generates one Effect, and one Proper Consumption quality. Ingredients are logged. These become qualities of both the formula and the potion. One potion matching the formula is generated.
On a failure, no formula is generated, but a potion is, with one random Effect quality and no Proper Consumption quality.
2) An Effect is named and two Arcane Lore tests are made:
a) On a success, two Ingredients are randomly generated and added to the formula.
On a failure, no qualities are generated.
b) On a success, one Proper Consumption quality is randomly generated and added to the formula.
On a failure, no qualities are generated.
Producing Potions:
A PC must have a formula and a laboratory. Two ingredients are combined and consumed, and an Arcane Lore test is made.
On a successful Arcane Lore test, a potion matching the formula is generated.
On a failed Arcane Lore test, nothing is generated.
Altering Formulas:
A successful Arcane Lore test in a laboratory allows one already-generated quality of a formula to be altered to another result from the same category of the PC's choice. The new quality must already be recorded in the PCs' logs.
A failed Arcane Lore test in a laboratory allows the referee to alter one quality of the formula or to generate a new quality if there is one undefined.
A successful Arcane Lore test in a laboratory allows one quality of a formula that is not already defined to be generated by the PC
A failed Arcane Lore test in a laboratory allows one quality of a formula that is not already defined to be secretly generated by the GM.
Mixing Potions:
By consumption:
1) Roll on the Side Effects table and apply the results with imagination, sadism and verve
2) The PCs check the list of ingredients of each potion to see if they can be assembled into any other potion(s). The potions are automatically created and consumed by the PC, and the effects applied.
3) For each additional potion created and consumed, roll an additional entry on the Side Effects table.
In a laboratory:
1) Roll on the Side Effects table and apply the results with imagination, sadism and verve
2) The PCs check the list of ingredients of each potion to see if they can be assembled into any other potion(s). The original potions are expended and a new potion created with the qualities of both the originals and any new potions their combination forms.
3) For each additional potion created by the combination, roll an additional entry on the Side Effects table.
