Potion Costs & Creation

Potions - Brewing, Researching and Selling

A potion is a magical item that is consumed or destroyed when it is used. The term 'potion' includes potions that reproduce spell effects and potions that have a unique effect and don't simply refer you to a spell description. You can also use these rules to create dusts, elixirs, ointments, oils, philtres, glues, and solvents but not bags of beans, ammunition, beads of force, candle of invocation, elemental gems, feather tokens or scrolls.

Proficiency Checks

If a proficiency check is required during the brewing process it should be made using Intelligence (arcana or proficiency in alchemy). If the DM agrees, the character may substitute this with proficiency in the healers kit or the poisoners kit for appropriate potions.

Potion Level

A potion has a level between 1 and 9. This defines how complicated the potion is to make, how expensive it is and how long it takes to brew.
The level of a spell potion is equal to the level of the spell it reproduces.* The level of any other potion is equal to the highest level of spell effect it reproduces, if any. If not, then the level is based on its rarity as listed in the DMG. The level for dusts, elixirs, ointments, oils, philtres, glues, and solvents is based on their rarity as listed in the DMG.**
* Using these rules means that the rarity of some potions varies wildly from that listed in the DMG. ** I am including an arbitary modifier for items based on the number of doses in the item description. Single dose items fall in the lowest level for the rarity category, whereas multiple dose items fall into the highest.

Potion Level	Spell Level	Creator Level	Rarity	Cost	Brewing Time	Difficulty
1	Cantrip	3rd	Common	50gp	1 day	10
1	1st	3rd	Common	50gp	1 day	11
2	2nd	3rd	Uncommon	200gp	2 days	12
3	3rd	5th	Uncommon	400gp	3 days	13
4	4th	7th	Rare	800gp	4 days	14
5	5th	9th	Rare	1200gp	5 days	15
6	6th	11th	Very Rare	1800gp	6 days	16
7	7th	13th	Very Rare	2500gp	7 days	17
8	8th	15th	Very Rare	3000gp	8 days	18
9	9th	17th	Legendary	4000gp	9 days	19

Potion levels of specific items

Dust of Disappearance - 2, Dust of Dryness - 3, Dust of Sneezing & Choking - 2, Elixir of Health - 4, Keoghtom's Ointment - 3, Oil of Etherealness - 4, Oil of Sharpness - 6, Oil of Slipperiness - 3, Philtre of Love - 3, Sovereign Glue - 9, Universal Solvent - 9.

Potion levels of non spell potions

Climbing - 1, Fire Breath - 3, Heroism - 4, Invulnerability - 4, Longevity - 6, Poison - 3, Resistance - 3, Vitality - 6, Water Breathing - 3, Giant Strength: Hill - 3, Frost/Stone - 4, Fire - 5, Cloud - 6, Storm - 9, Healing: Basic - 1, Greater - 3, Superior - 4, Supreme - 6.

Potion levels of spell potions

Animal friendship - 1, Clairvoyance - 3, Diminution - 2, Flying - 3, Gaseous form - 3, Growth - 2, Invisibility - 2, Mind reading - 2, Speed - 3.

Recipe

To create a potion you need a recipe. A recipe consists of a list of ingredients and a description of the brewing process. The higher the potion level, the more complex the recipe. There is a 25% chance that any random spell scroll found will actually be a recipe for 1d3 random potions, one of which will be a potion with a level equivalent to what the spell scroll would have been.

Ingredients

Ingredients vary by potion and recipe. The same potion may have several different recipes. A potion has one significant ingredient per potion level. So a level 1 healing potion has one significant ingredient and potion of cloud giant strength has 6. If a potion has ingredients listed in its description in the DMG it should be included as part of the recipe.
E.g. To make a potion of healing;
"Take the bark of a black aspen tree, less than a single handful. Strip the bark into two piles, the inner bark in one, the outer in another. Simmer the inner bark in boiled spring water upon a wood fire kindled with the outer bark."
A researcher would see one ingredient, Black Aspen bark. They might try to substitute another type of willow bark, they may try to use a different kindling, water from a well and so on. And every region and culture may have it's own recipe for a potion of healing based on the local plants available.
There are several types of ingredients. I suggest a different type of ingredient per level of potion. The more expensive the potion, the rarer the ingredients. 80% of a potions cost is in the ingredients. (The other 20% being time, fuel, equipment costs, the cost of the bottle and stopper, living expenses and possibly hush money). Pricing individual ingredients is an exercise left to the reader, but I'd suggest only making one or two ingredients expensive or hard to obtain.

Types of ingredients

• A particular portion of a plant, herb or fungus. (e.g. Mandrake root, mistletoe berries, a seed of the tree of life, fly agaric or a blossom from the mane of a rosebush lion).
• A particular piece of an animal or monster. (e,g cow dung/urine, eye of newt, griffin feather, griffin egg, a dragon's heart or the fat from a hanged murderer).
• A base liquid. (e.g Oil, spring water, alcohol, milk, a dryad's tear, jellyfish squeezin's, liquid moonlight).
• A mineral or metal. (e.g Cold iron rod, chalk, fine gold wire, a star sapphire, moonrock, a millstone).
• A complex substance such as honeycomb wax, a glazing, an emamel, pitch, paper, amber, or a love letter.
• A spell requirement additional to the spell effect being created. (Use only a mage hand to lift. The process must be in complete silence. Stand behind a wall of force for the next bit).
• A place with a particular quality or something with the essence of that place. (in view of the sun, cool upon mountain snow, The room needs to be HOT and SMOKEY!).
• A particular tool or object. (e.g a marble mortar and pessel, a ground up holy symbol of Tyr, a crucible carved from ice, a glass mixing rod or a crossbow bolt that has slain a goblin).
• an acid, reagent or catalyst. (Silver coin in the pot, spray a mouthful of vinegar over the open pot, a bit of corn starch to thicken it up).
• Another potion, toxin, antidote or alchemical device. (e.g. A potion of healing, an antidote to scorpion venom, holy water, alchemist's fire).

You should avoid including things like astrological conditions or specific locations unless they could be completed within the time limit of the brewing process. In addition a recipe will have one or more steps that needs to be carried out including powdering, mixing, brewing, distilling, infusing gas through liquids, cooling, baking slowly, mixing vigorously, mixing oh so carefully, basting, lining the bottle, preparing the right seal and so on.
If you allow non spell-casting alchemists to create potions, then the recipe should definitely include ingredients with rare mystical origins. You may even want to consider two types of recipes, easy ones for spell casters who know the spell effect desired and recipes with more complicated processes for anyone else.

Equipment

A full alchemical laboratory consists of furnaces, tools, heat pans, benches, shelves, and lots and lots of curly glassware. A laboratory has a level and the cost of a laboratory is equal to the cost of one potion of the same level. The alchemical supplies in the PHB provides a basic alchemical set-up with which to brew potions and should be considered a level 1 laboratory. To upgrade a laboratory, simply pay the difference in cost between the current lab and the level of lab required. An alchemist's shop will always have at least a 1st level lab. Laboratories do not have a maintenance cost beyond normal household expenses. Any special expenses are covered by the cost of brewing a potion.
Any laboratory of any level will allow a character to brew any potion. A more expensive lab merely provides additional options and advantage to some rolls during the brewing process. See the brewing section below.
A research library will also have a level and will similarly cost the equivalent of one potion of that level. See the research section below.

Brewing

A potion costs it's level squared x 50gp to make. Additionally, if it reproduces a particular spell then one set of that spell's material components is consumed by the brewing process. A potion takes 1 day per level to brew. This process must be attended to for 8 hours of each day. Under normal circumstances no roll is required to brew the potion.
If the process is interrupted or mildly disrupted (the brewer is called away, someone slept in, inappropriate finger tasting) then a character will need to make a proficiency check to rescue the situation. The difficulty of the roll is listed in the table above. If the roll succeeds, the character gets everything back on track and the process continues as normal. If the roll fails, the potion (and ingredients, time and money) is lost. If the process is actively disrupted (smashed glass, ingredients or processes tampered with, etc.) the potion is usually lost, but the DM may allow a roll to save it.
If a brewer has competent assistance, the parties involved can divide the workload. Competent assistance includes anyone who can brew a 1st level potion, an anyone with proficiency in the herbalism kit or poisoners kit, anyone with Arcana or anyone with Alchemist proficiency. If all parties could brew the potion by themselves then they can split the workload as they see fit. Otherwise the principle brewer must spend some of the 8 hours each day overseeing the process. The minimum number of hours they need to spend is equal to the potion's level (max 8 hrs) and the final day must always be fully supervised.
If the principle brewer somehow fails to attend the brewing process at an appropriate time, the assistant need to make a proficiency check to rescue that day's work. Being of too low a level to brew a potion in need of rescue gives disadvantage. Leaving a brewing process in the hands of an assistant who couldn't brew the potion by themselves is risky. At the end of the brewing process, the principle brewer will need to make a proficiency check to complete the process successfully. Trying to brew a potion without a proper laboratory is risky. At the end of the brewing process, the brewer will need to make a proficiency check to complete the process successfully.
A laboratory of equal or higher level to the potion being brewed gives advantage to checks. Trying to brew a potion without basic shelter gives disadvantage to checks.
Keoghtom's ointment and dust of dryness are always found with a number of doses. Roll this number immediately on completion of the brewing process.

Optional rule: Batch brewing

A brewer may attempt to make more than one vial of a potion at once if they have a working laboratory. They can attempt to make up to the labs level in potions at the same time. Only one type of potion can be brewed at a time. The brewer must have enough ingredients and pay the costs for each and every potion being brewed. Brewing in batches is more difficult, so a proficiency check is always required to complete the process.

Research

Researching a recipe is possible. In order to do so the character must match the creator level of the level of the potion. If the character has access to a magical library then they can make an Intelligence (Arcana) check against the difficulty of the potion level. A success means they figure out a viable recipe. Library research takes a number of days equal to the brewing time of the potion researched.
If they have access to an alchemical laboratory then they can make a proficiency check to discover the recipe. This is more of a trial and error approach. The materials cost is twice that of a regular potion and the brewing time is twice as long. At the end of the period, the character rolls the difficulty check. If they succeed, they have a viable recipe and one potion of that type. If they fail they get nothing, but there's nothing stopping them from trying again as long as they have the time and money. A character who has any two of the following conditions has advantage on the research roll. An arcane library of a level greater than or equal to the level of the potion, an alchemical laboratory of a level greater than or equal to the level of the potion, a qualified researcher assisting them, ability to cast the spell effect the potion will reproduce, or a partial recipe. A character with none of those conditions has disadvantage on the research roll.
A partial recipe is when the character knows something, but not everything about the brewing of the potion being researched. They may have damaged fragments of a recipe, they may have a list of ingredients, an incomplete or second hand description of the process, witnessed a laboratory set up from a distance or had the chance to examine a laboratory that hasn't been cleaned up since it last brewed a potion etc.
A character who is proficient with a herbalism kit already knows the healing potion recipe and doesn't need to research it. A character who is proficient with a poisoners kit already knows the potion of poison recipe and doesn't need to research it. A character who is proficient in alchemy will know the recipes of 1d3 common potions.

Source - TrapperQ on https://forum.rpg.net/index.php?threads/5e-alternative-magic-item-rules.752072/