Potion Brewing (ech, agh, bleh)

For GLOGtober '23, per SunderedWorldDM's challenge:

Potions and how to brew them.

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Potions are spells for non-casters. They're more or less identical to scrolls, depending on your ruleset.

Potions are more interesting than scrolls as treasure because they usually don't come with instructions. Instead, you have to take a whiff/sip to figure out what it does: "if a whiff gave me vertigo and blew bubbles out my ears, what would chugging the bottle do?" it's fun, it's cute, 10/10 good rpg mechanic

[You can cast from illegible scrolls, but they don't have the same "take a sip" gameplay that potions do. They're still interesting, but in a different way.]

Anyway.

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I think the appeal of brewing a potion is that it's Kinda Like Cooking™. Creating a scroll is very abstract, but anyone can throw shit into a cauldron and turn on the heat.

So, first proposal for a potion brewing system: Throw a Feast. Magical ingredients like dragon toes and acid jelly and unicorn tears give you a spell for the day you can cast from your belly. The more you spend on the feast, the longer the effect lasts/the more MD you get.

pros: gathering numinous ingredients is Cool Gameplay; i have yet to meet a player who doesn't want to eat a monster; before (and sometimes during) a delve you get to rp having dinner with your hirelings and camp followers and Unlikely Allies; piggybacks onto existing magic system, is otherwise extremely mechanics-light

cons: can't "chug a pot" mid-combat; low chance of cauldron blowing up in your face; no opportunity to play a "mad alchemist" character, which is the whole point of adding a potion brewing subsystem, i guess

Here's an alternative:

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If you're an alchemist, or a witch, you start with a cauldron (big enough to fit a human body, just in case). Good cauldrons are expensive; like, 100g.

It's made of cast iron (get it? cast?)

The cauldron is the most important part of potion-making. If you don't have a cauldron, you're shit out of luck.

• If you know a spell, you can make a potion of that spell for 50g. This is trivially easy.

• If you have a recipe of a spell, you can make that potion using its primary ingredients. This is stuff like troll heartstring and gypsum: things that are difficult to get your hands on but ludicrously effective once you've got them. You can still substitute generic ingredients (eye of newt, etc etc) for 50g.

[note: if you have a reliable source of primary ingredients, you can make a lot of potions. enough to flood the market, or reliably breathe water all the goddamn time. This is what makes potion recipes Very Good Loot]

• If you don't know a spell, you can experiment. Drop 10g basic reagents + other ingredients into your cauldron. Roll 2d6 + 1d6 for each sufficiently numinous and hard-to-acquire ingredient:
• No multiples: inert sludge
• Doubles: explosion, noxious smoke; 1 vial of poison, effect scaling with the number rolled (see below)
  
• Triples: you get a potion! now figure out what it does :dmthink:

[optional rule: no smoke cloud on doubles, DM rolls secretly; players must determine experimentally whether the result is sludge, poison, or potion]

Write down the result of the experiment: it is now a defined in-universe recipe

No matter how big your cauldron is, you only get one dose at a time. (As everyone knows, the first few drops hold all the potency; the rest is just broth)

Doubles Value	Poison
1	1d6. Odorless, colorless.
2	Induces weakness.
3	Induces vomiting.
4	Induces sleep.
5	Induces mutation.
6	Slow, certain death. Can be delayed, but never evaded.