Potions are an adventurer's best friend, but it's not always sensible—or realistic—to carry a few dozen potions at once. When you need to carry a lot of potion in a little container, use a flask.
This chapter introduces potion flasks and rules on how to use them in your campaign.
A flask is a small, magically-infused bottle (or other container) that can safely hold a large—but uncertain—amount of consumable potion (or other liquid).
Unlike potions, which typically come in single-use vials, it's always hard to tell exactly how much liquid remains inside a flask—you never quite know how many uses you'll get before it's all gone.
The Flask Die
Instead of tracking individual drinks, flask quantity is measured with a die—d8, d10, d12, etc. This is your Flask die—roll it whenever you take a drink from the flask: if you roll a 1 or 2, the die gets one size smaller:
If you roll a 1 or 2 on a d4, that's it—the flask is now completely empty until you can find a way to refill it.
d20 → d12 → d10 → d8 → d6 → d4 → 0
- GM:The wizard's lightning bolt hits you for 11 points of damage, Clanda. What do you do?
- Clanda:Damn it, I'm bloodied. Can't risk another hit like that—I'll take a drink from my flask of healing as a bonus action and get... 7 hit points back.
- GM:Great, now roll your flask die.
- Clanda:Flask quantity is d4, so I roll a d4 and get... (rolls 1) ...damn—looks like that was the last of it.
|Quantity||Remaining Uses (Average)||Cost to Buy|
|d20||30||22 x base potion cost|
|d12||20||15 x base potion cost|
|d10||14||10 x base potion cost|
|d8||9||6 x base potion cost|
|d6||5||3 x base potion cost|
|d4||2||1 x base potion cost|
Magic fades quickly from any liquid leaving the flask. If you pour the contents of a flask into another container—such as a potion vial, a cup, or a different flask—the magic fades within one round, becoming useless if not consumed during that time.
Getting a Flask
There are three common ways to gain a flask: find one on your adventures, buy one from a merchant, or—if you have the right tools and training—create one.
Treasure & Rewards
You may find a flask on your adventures—in the ruins of a wizard's tower, on the corpse of a dead explorer, in the locked chest of a rich merchant—or be awarded one as a reward for some heroic deed. Flasks found as treasure will usually have a d4 or d6 quantity.
Buying a Flask
Flasks are an uncommon item that, depending on your setting, may not be easily available. If you can find a vendor selling flasks, an empty flask is a small item that costs 5 gp.
The cost of a partially-filled flask will depend on its quantity and contents—see the Average Uses & Costs table for an exact breakdown.
Valiant wants to buy a flask of healing with d6 quantity. One potion of healing normally costs 50 gp, so the flask will cost him 150 gp (3 x 50).
This flask contains d6 drinks of healing potion. When you take a drink, roll a flask die—if you roll a 1 or 2, the flask quantity gets one size smaller.
Creating a Flask
If you are proficient with both the Arcana skill and a set of appropriate artisan's tools (glassblower, smith, woodcarver, or potter), you can attempt to create a new, empty flask during a long rest.
Creating a flask costs 5 gp of materials and requires a successful DC 15 Intelligence (Arcana) skill check—on a failure, the flask shatters and is rendered useless.
Filling your Flask
If you have an empty flask and are proficient with an alchemist's kit, you can fill an empty flask yourself by combining together potions of the same type and pouring them safely into the flask. This can be done during a short or long rest.
If you don't have the requisite tools or experience, you'll need to find a trained alchemist to perform this service—pouring any ill-prepared potions into a flask will spoil the mixture, nullifying any magical properties.
|Potions Used||Flask Quantity|
Refilling your Flask
Potions are volatile and don't like to be mixed. If you pour any potion—even one of the same kind—into a partially-filled flask, the contents immediately spoil and lose all magical properties.
Variant: Mixing Potions
If you want to include some variety when mixing potions in flasks, roll a d20 on the table below. This roll should be done in secret—the player does not notice any change without first making a successful identifying action.
|1-5||The contents lose their original properties and become a potion of poison.|
|6-16||The contents are spoiled and lose all magical properties.|
|17-19||No change in the contents.|
|20||The contents lose their original properties and gain the effect of the newly-added liquid.|
Variant: Topping Up
If you are proficient with an alchemist's kit, you can top-up a partially-filled flask during a short or long rest if you have enough potions. As a proficient alchemist, this does not risk spoiling the contents of the flask.
|Flask Quantity||Potions Needed|
|d4 → d6||+2|
|d6 → d8||+3|
|d8 → d10||+4|
|d10 → d12||+5|
|d12 → d20||+7|