[Shaira]

Thanks everyone for the ideas and input!

My goal at the moment is to have some loose rules in the background for me to be able to use potions in play, rather than immediately having lots of alchemist PCs trying to make potions - I need to work out what potions are and how they work in the BRP rules rather than strictly speaking how to make them.

That said, I'm leaning towards a "Science (Alchemy)" skill, and having an alchemical equivalent to the Sorcerous Grimoire where alchemists keep all the formulae for their brews. I've divvied up potions into 4 types:

i.) Poisons
ii.) Poison Antidotes
iii.) Herbal Potions (slow healing, augment certain skills or characteristics, etc)
iv.) Magical Potions (potion of flight, etc)

Within those categories, I'll create some basic "formula descriptions", analogous to spell descriptions. There'll be a generic "Create Poison" description, for example. Poisons, Poison Antidotes, and Herbal Potions don't require any magical energy to create, just time and the correct ingredients, plus knowledge of the formula and sufficient skill. Magical Potions require the knowledge of one or more Spells, plus may require some very arcane ingredients (eye of medusa, etc), and - depending on formula - will require at least PP expenditure, and maybe even POW expenditure in some cases.

Hopefully this should be flexible enough to emulate what a fantasy campaign needs in terms of potions. The standard "Spell Potion Formula" is probably the most important to work up into a formula, as that's the one that's trickiest to tie in with the BRP rules. For that, I'm toying with three ideas:
i.) Require PP only, and no permanent POW sacrifice
ii.) Require PP and POW sacrifice for a large number of doses
iii.) Require an initial POW sacrifice to enchant parts of the alchemical lab to make a specific potion, then PP after to brew individual batches.

I'm leaning towards (iii) - it actually follows (more or less) the BRP "Equipment with Powers" rules, plus allows relatively unlimited amounts of potion to be brewed as long as PP and ingredients are available. It also has the added advantageous side-effect of making alchemical labs very personalised and therefore valuable to the individual alchemist.

I'll keep brainstorming and post a draft when it's a bit more complete. Feedback is very welcome!

Cheers,

Sarah