There are several things to keep in mind when you are using these formulas for your campaign or for making your own formulas. As with any magic item, a formula can affect the balance of your game. Carefully review the effects of its resulting item and think about how difficult it will be to make. If it contains a material that isn’t normally obtainable by the party, then it won’t heavily affect game balance since you can control how much they find. If they can obtain or purchase an indefinite amount, then a formula effectively adds a new ability the party can use in exchange for resources and downtime. It is also best if the resources that go into a potion aren’t so prohibitively difficult that it isn’t worth making at all.
Here are two more magic potion/oil formulas, a feat, and some guidelines for adding ability checks to your magic item creation.
Formula: Oil of Sharpness
To make this oil, you need simply follow these instructions:
- Gather 20 pounds of high-quality rust monster dung. You will need to feed the rust monster a consistent, steel-rich diet, and if multiple rust monsters are used, they should be of similar size and breed.
- Load the dung into a brick kiln with one opening for loading dung, another for unloading charcoal, an eyehole at the top for smoke to escape, and vents along the bottom to control airflow.
- Ignite the dung and subject it to slow pyrolysis, burning it in a low-oxygen environment for roughly a week. The smoke coming from the eye will initially be white and then yellow and then bluish or clear. When it reaches the third stage, seal the air vents, leaving only the eyehole open to release volatiles for 2 days, and finally seal the eyehole for cooling. This produces an alchemical substance called rust coal.
- Rust coal will burn metal in a manner similar to how wood burns, but it releases toxic fumes, and the metal becomes rust instead of ash. Use the rust coal with a furnace and bellows to burn an expertly sharpened mithral longsword at a high heat until it is reduced to a fine pile of rust. After it cools, carefully sift through the rust to find tiny, ultrathin silver shards.
- Suspend the shards in mineral oil and seal in an airtight container. This is the oil of sharpness.
Formula: Potion of Water Breathing
To make this potion, you need simply follow these instructions:
- Oysters exposed to an aboleth’s mucus cloud will mutate, and their shells will turn translucent. The pearls from these oysters are filled with a pink gelatinous substance called jooba jelly. This jelly has the properties of aboleth mucus. Collect one “pearl” of jooba jelly.
- Place the pearl in a freshwater tank or pool with a lungfish and check it twice daily. Over time, the lungfish will filter the potency of the jooba jelly, reducing its harmful side effects. Within a week, the pearl should begin to float, and its outer shell will be thin and flexible enough that it resembles a small jellyfish.
- Being careful not to rupture it, remove the pearl and seal it in an airtight flask with greenwater—seawater rich with living algae. The algae solution will preserve the jelly indefinitely. This is the potion of water breathing.
Option: Alchemist’s Supplies Checks
You may wish to add ability checks as part of the harvesting and crafting process. Here are some guidelines. To harvest a fantastical material, the character makes an ability check using alchemist’s supplies against a DC determined by the rarity of the formula that is being worked on, as outlined below. You could also require checks as part of the process of creating an item. The most difficult step can have its difficulty based on the formula rarity and other steps requiring a check would be one stage easier. Generally, alchemy uses Dexterity or Intelligence. Adding some checks to the process can be fun, but be careful not to overdo it and cross into tedium.
Alchemy Ability Checks
You have studied alchemy extensively and gain the following benefits:
- As part of a short rest, you can use alchemist’s supplies to create an alchemical admixture using two alchemical consumables that are used in the same way (such as two potions or two oils applied to the body). The admixture confers the benefits of both consumables when used. You can’t combine two admixtures together in this way.
- You gain proficiency with alchemist’s supplies if you don’t already have it. Double your proficiency bonus when making an ability check using alchemist’s supplies.
- When you finish a long rest, you can use alchemist’s supplies to create a number of magical minor potions equal to your proficiency bonus. Once drunk, a minor potion’s effect lasts for 1 hour. A minor potion loses potency after 24 hours and has one of the following effects of your choice:
Ability. Choose an ability score when you create the potion. When the drinker makes an ability check with the chosen ability score, they roll a d4 and add the number rolled to the check.
Ironskin. Any critical hits the drinker suffers become normal hits instead.
Potence. Once during their turn, when the drinker damages a creature, they can deal an extra 1d4 damage to that target.
Protection. The drinker gains a +1 bonus to all saving throws.