(Go see wr3cking8a11's fulfillment of my request at A Swamp In Space!)
I got close, in a teaching-your-players-to-fish sort of way.
As it turns out, I had a whole system written up for my 5e game for on-the-fly alchemy. It started out as houserules for--and then a heavy modification of--a DM's Guild job called "Kaziquek's Guide to Alchemy". I can't actually recommend buying it, per my (unreasonably?) high standards; it's got some good ideas, but the execution ends up a mash of tracking inventory on 107 standard and 107 unique ingredients, then combining them in specific ways to produce individual recipes with deterministic drawbacks.
I ran it as written and found that my players ended up carrying around a bag of holding with hundreds and hundreds of samples of cave mushrooms, copper powder, egg yolk, and newt tails, with no clear rules for finding stuff in the wild, bulk purchases, or creation methods... Ultimately, the level of descriptive detail just didn't gel with the resolution of the game world's simulation.
So I wrote my own version. The 5e ruleset is here. The lingua franca of the OSR blogozone is B/X-ish-compatible GLOG variants, however, so we're gonna try to cut down that 5e-focused document into a lean, hard, game system. Thus:
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A Schema for Field Alchemy - Or, GLUG GLOG GLOP
FIELD ALCHEMY is the practice of rapidly combining essential ingredients into mostly useful concoctions. Through the alchemical arts, common ingredients may have their essences extracted, magnified, and put to use...along with a few attendant side effects.
To make a concoction, the alchemist must combine two ingredients, a metallic essence, and enough heat to boil water for an hour.
(In effect, the player spends time and money to produce variable effects; they can spend more time to narrow the variability of the outcome. Metallic essences are the DM-tweakable reagent that limits how many concoctions the player can produce.)
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| You will imagine yourself as this guy. This is not the case. (Der Alchemist by Joseph Leopold Ratinckx) |
Ingredients are chunks of Animals, Plants, Minerals, or Mystic Substances. If you find a source of one of those things, you can spend a turn to roll under INT to extract a useful sample. Spending additional turns to roll again can yield additional samples--it shouldn't be a problem during downtime to find animal, plant, or mineral ingredients, and wandering monsters are a balancing threat against extended collection expeditions in dangerous places whereas there's no reason to not allow the arbitrary collection of materials during downtime--inventory slots are the limiting factor there.
Ingredients fit three to an inventory slot; imagine a kidney, a whole ginseng root, a lump of quartz, or a snifter of finely-ground wizard teeth. No prices are listed for basic ingredients--it's trivial to gather them for free in the wild, and existing equipment lists offer plenty of examples of prices for chunks of meat, wood, and such. Lean on player ingenuity and a material's origin to figure out if something gathered in the field is a valid categorical source of ingredients.
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| Dried chameleons. A drawer full of Animal ingredients. |
Metallic essence is a highly-refined sample of alchemically significant metals that determine the potency of a concoction. The ingredients are useful, but they are transformed through the presence of the metallic essence--merely mashing together goblin giblets does not a philter make. It's not possible to refine metallic essence in the field--you need fragile distillation equipment and at least a full day in a safe place. Metallic essences are small enough that they don't fill inventory slots unless you're hauling around a damned crate of them.
Also, they're rather expensive, and the effects of chugging incredibly pure samples of lead powder are left as an exercise to the reader.
- Lead Essence (Save at +2) - 3 GP/vial
- Tin Essence (Save at +1) - 5 GP/vial
- Iron Essence (Save at +0) - 15 GP/vial
- Copper Essence (Save at -1) - 30 GP/vial
- Silver Essence (Save at -2) - 50 GP/vial
- Gold Essence (Save at -3) - 100 GP/vial
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| Nanoscale tin powder. Don't breathe it! |
Concoctions are categories of alchemical substances produced by combining two kinds of ingredients:
- Vegetable + Mineral ingredients produce Boosters.
- Beneficial concoctions, usually physically consumed by the user
- Animal + Vegetable ingredients produce Medicines.
- Also known as poisons, depending on the dose
- Mineral + Mystic ingredients produce Hazards.
- Traps, explosives, and other dangers; usually thrown or placed as weapons
- Animal + Mystic ingredients produce Mutagens.
- Some helpful, some harmful. Usually consumed (or fed to someone you dislike)
Unfortunately, field alchemy is as much an art as it is a science. The alchemist selects a category for the concoction to be produced, but rolls randomly on the associated chart for both the concoction's effect and side effect.
More ingredients can be consumed to guide the concoction toward a more desirable result--a pinch of gall, a dusting of aether as the pot boils.
- One sample each of two ingredients: a random roll on the desired concoction category chart.
- Two samples each of two ingredients: two rolls on the desired chart; the alchemist picks which one they want to use. Extra ingredients are lost.
- Three samples each of two ingredients: the alchemist selects the desired outcome from their chosen category. Extra ingredients are lost.
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| I may have written this entire thing just to post this picture. (We are NOT taking the wizard by MattRhodesArt) |
Side effects are always randomly rolled. Sometimes, the side effect is more useful than the concoction in context. The alchemist always knows what the effect of the concoction and the side effect it carries are once the concoction is created.
Booster Side Effects (Cosmetic) (1d6)
1. Anything touched by this concoction is profoundly stained.
2. The site of application remains unpleasantly moist and slimy. If consumed, you loudly hack up slippery goo as long as you're affected.
3. The concoction produces brief, obvious illusions near it based on the surface thoughts and emotions of the consumer.
4. The concoction produces extreme hair growth wherever it touches bare flesh. The growth rate lasts for one week.
5. The concoction emits a disgusting smell both before use as well as for a full hour after use. Your burps are hella gross.
6. Cosmetic mutations suffered while under the effects of this concoction are permanent.
Medicine Side Effects (Mental) (1d6)
1. Blackout. Save or forget everything from 30 minutes prior to exposure/consumption of the concoction.
2. Brain Fog. Save or roll under half INT whenever a roll under INT would be called for.
3. Paranoia Agonist. Saves against fear apply the concoction's metallic essence save modifier. Can be beneficial or harmful.
4. Aggression. Save or creature's default reaction to strangers is hostility, and they perceive all unfamiliar creatures as equally hostile.
5. Mood Swings. Save or roll under half CHA whenever a roll for social interaction is called for.
6. Traumatic Hallucinations. Save or suffer a very, very bad trip. Roll under half INT, WIS, and CHA whenever such are called for. Vividly remember hallucinations.
Hazard Side Effects (Functional) (1d6)
1. Itching. Exposure to the concoction requires a save, or the creature one out of every three rounds scratching itself for the next hour.
2. Jitters. Save or the creature drops whatever it is holding at the moment the concoction takes effect.
3. Reaction Delay. Save or the exposed creature always acts last in initiative for the concoction's duration.
4. Heart Murmur. Save; on a critical failure the creature suffers an immediate heart attack and dies if their heart was important. Otherwise, nothing but a brief shiver.
5. Muscle Relaxant. Creature exposed ignores 3 damage from each source of blunt impact; rough travel is vastly more comfortable. Hard to feel a delicate touch.
6. Clouded Vision. Save or clarity of vision is limited to 20 feet for the concoction's duration.
Mutagen Side Effects (Physical) (1d6)
1. Numbness. Save or roll under half DEX (and anything keyed off of DEX) for the next hour.
2. Ravenous Hunger. Consume one ration each turn for the next hour or save; on a failure, lose half of current remaining hit points.
3. Emetic. Immediately expel contents of stomach, making a mess and ending the effects of any consumed concoctions or poisons.
4. Metabolic Collapse. Save or immediately fall deeply asleep for one hour; nothing short of actual HP damage will wake you before your elapsed naptime.
5. Toxic Fumes. This concoction constantly vents toxic gas; take 1d6 damage each hour it is kept on (or in) your person. A potent antiparasitic, if you can survive it.
6. Poisoning. Save or take 2d4 damage. On a critical failure, take 4d6 damage. If this kills you, your demise is extraordinarily messy--everything squirts out both ends.
Extraordinary Ingredients: If you harvest your ingredients from a remarkable source--a 10 HD creature, a thousand-year-old tree, extraterrestrial metals, or the ephemera of a unique magical phenomenon or construction--you can roll under your INT to make a special version of a concoction: The effect of the concoction and the side effect it produces is permanent.
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I started writing a list of bespoke concoctions, but I realized that was silly--we have a gorillion potion lists out there. This system is meant for figuring out how to make them, and what their curious side effects are.
Potions discovered in the wild should generally be without side effects, as they were (probably?) created in controlled environments, not desperately boiled in a steel helmet full of river water and scrapings from the tailing piles of a mithril mine while troglodytes pounded on the door you'd spiked shut. Field alchemy is about doing the best with what you have in the moment.
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| You are probably going to end up more like this guy. (Dmitry Burmak) |
But as an example, here's the first 20 entries from Arnold K's potion list sorted into Boosters, Medicines, Hazards, and Mutagens.
Boosters
1. Clairvoyance - By designating a location within 100', you can see that location as if you were there. You can look at a different location each round. Lasts 1d6 rounds.
4. Fire Resistance - All incoming fire damage is reduced by 6 points. Lasts 30 minutes.
8. Heroism - You get +4 to all d20 rolls. Lasts 1d6 rounds.
10. Invincibility - You are immune to damage. Lasts 1 round.
11. Nondetection - All magical attempts to learn about you fail. People forget you exist as soon as they stop looking at you. Lasts 30 minutes.
17. Spider Climb - As the spell spider climb. Lasts 30 minutes.
Medicines
2. Deadly Poison- Created by feeding a chain of poisonous animals to each other. Poison (2d6).
7. Healing - You recover 1d8+1 hit points.
14. Purge - Any poisons in your body are vomited out intact. You can vomit the poison into the (now empty) potion bottle if you wish.
Hazards
16. Sovereign Glue - Elemental stickiness. Glues anything to anything, forever. Very difficult to see if spread on a surface.
18. Universal Solvent - Dissolves any adhesive. Neutralizes sovereign glue and sovereign grease. Causes hard materials to become softer. (Stone becomes like clay, adamantine becomes as soft as normal steel.) Don't get it on your hands.
Mutagens
3. Flight - You gain a fly speed of 24. Lasts 1d6 rounds.
5. Gaseous Form - As the spell gaseous form. Lasts 30 minutes.
6. Giant Size - You triple in size. Your physical attacks deal double damage and you take half damage from physical sources. When making Strength checks, treat your Strength at 24. Lasts 1d6 rounds. Alternatively, it can be poured on an object or part of an object to make it triple in size. Lasts 30 minutes.
9. Invisibility - You are invisible. If poured on a wall or floor, creates a psuedo-window that you can see through. Lasts 1d6 rounds.
12. Petrification - Turns you into stone. If poured on stone, turns it into flesh.
13. Polymorph - A piece of a creature must be added to this potion before it can be used. You transform into an exact copy of that creature. Multiple donors creates chimeras. Lasts 30 minutes if same species or 1d6 rounds if different species.
15. Shrink - You shrink to a twelfth of your normal size. (Feet becomes inches.) Your Strength is 1, all of your attacks deal a single point of damage, and you take double damage from physical sources. Lasts 30 minutes. Alternatively, it can be poured on an object or part of an object to make it shrink down. Anything smaller than a couch can fit in your pocket. Lasts 30 minutes.
19. Water Breathing - You can breath underwater. Lasts 30 minutes.
20. Zombie Blood - You appear to be a cold, rotting corpse but can still act normally. Unintelligent undead will ignore you as long as you ignore them. You count as undead. Lasts 30 minutes.
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In summary:
0: The DM populates the Booster/Medicine/Hazard/Mutagen charts from their preferred potion list.
1: The player gathers Animal, Vegetable, Mineral, and Mystic ingredients and buys Metallic Essences. The GM decides how many metallic essences are available for purchase.
2: The player decides to perform Field Alchemy, picking two ingredients and a metallic essence to combine into a type of concoction.
3: The player rolls for the concoction's effect (or picks, if enough ingredients are used) and rolls for the side effect, producing a useful (?) result.
You should have something that requires minimal bookkeeping, is self-limiting (through inventory slots and access to metallic essences), has a power level set by the GM (based on the potion lists converted into alchemical results), and has limited potential for power gaming (due to semi-random outcomes).
There's plenty of space here for refinement (ha!). Lists of known recipes, unique effects, magical alchemical equipment, delivery methods... Go scrape out your field cauldron and give this stuff a test.
