I have a player who wants their PC to drink a potion underwater while one-handed, and as a DM I'm not sure how to rule it.

Ask for a Dex check? What DC? Is it even possible? I couldn't find anything in the books about using potions underwater in the first place, and I don't know how to rule it myself. The main problem I see is the potion simply spilling into the water, so knowing how potions work underwater in the general case of having two hands available would be a good start.

How do I make a ruling about this?

  • 3
    \$\begingroup\$ This question and answer has been featured on Kotaku. \$\endgroup\$ – TylerH Aug 18 '16 at 14:26
  • 20
    \$\begingroup\$ Welcome, Kotaku readers! Just a FYI: This place works a bit differently than a forum, so before attempting to post something in good faith, take our tour to learn what the “gotcha” differences are. Cheers! \$\endgroup\$ – SevenSidedDie Aug 18 '16 at 14:53

10 Answers 10


I am a huge dumb nerd so I just went and proved this for myself with a bathtub and a bottle of Red Guitar. By pulling the cork with my teeth and immediately folding my thumb over the lips of the bottle, I managed to leak only the merest iota of wine. If I had the clearance to stand upright instead of kneeling there, like a moron, dunking my head and holding the bottle sideways, then the only leak would have been from the margin of air at the top of the container.

Having replaced the seal with my finger, it was then no effort to simply wrap my lips around that of the bottle's, extract my thumb, and admit air from my lungs to equalize the pressure and allow a couple of sips. You can do this yourself without getting your head wet or finding a beverage with a cork.

So my answers is yes, this is a trivial exercise. Even asking for a DEX check would be too much. Only a small child would have a particularly difficult time with this. You might as well ask for a STR check to extract your foot from your shoe.

You may be wondering, "Eikre. Did you seriously get up and run a bath just to have citational highground over the armchair theorists?" All I have to say for myself is that there is a distinct possibility that the sangria I drank in the course of the experiment was not exactly the first sip of the day.

  • 3
    \$\begingroup\$ Comments are not for extended discussion; this conversation has been moved to chat. \$\endgroup\$ – mxyzplk says reinstate Monica Aug 15 '16 at 12:51
  • 22
    \$\begingroup\$ And by "the conversation has been moved to chat," that means that the conversation has been moved to chat. \$\endgroup\$ – mxyzplk says reinstate Monica Aug 17 '16 at 2:09

After reading Eikre's answer, I thought, sure you can.. but what about swimming? and since I live near the beach..

So, The Answer is "with extreme difficulty" if the water is moving.

Having to keep an arm free to maintain position and not get drawn to the surface or swept along with the undercurrent, does require the DEX check, determined by the waters movement, but probably only for someone with very few points in swim. But.. trying to de-cork a wine bottle with my teeth at the same time.. that was the kicker..

On the beach, I unstoppered the bottle, returned to the waves and tried again with my finger over the lip, Yes, not too difficult, though a wave did force some of the wine out, and I could taste salt water in the next sip.

The bigger problem as what others have already pointed out, is that it won't come out in a single chug, You can attempt to suck it out, getting maybe 15mls, letting air back in the bottle to reset the pressure, or vice versa blow into the bottle for the same. might take some time.

Turning myself upside down to get it to flow down, did nothing with a full bottle, but almost drowned me when I had already taken around 150mls (I kid, I just got flustered as the wine swashed down into my mouth, unexpectedly and I lost pretty much all of what was in my mouth to get to the surface).

My GM ruling would be Dex/Swim check determined by water movement, it should take about a minute to 'sip' the contents out, without spilling, and Wil save to not get flustered if anything causes the character to panic (spotting a shark, getting turned upside down by a wave, being shot at or the water temperature suddenly changing)

  • 3
    \$\begingroup\$ Thanks for addressing my curiosity about actually doing this in a current. Although, now I have to wonder "are players carrying potions around in standard wine bottles, and is that an Intelligence or Encumbrance check?" :) I've always assumed any "potion" infers a concentrate in a tiny bottle (say 50 mL, rather than a normal-strength beverage in a standard (750+ mL) bottle. \$\endgroup\$ – brichins Aug 18 '16 at 23:50
  • 2
    \$\begingroup\$ youtube.com/watch?v=LLQT_Q5ZrPU \$\endgroup\$ – BaneStar007 Aug 19 '16 at 5:08
  • 2
    \$\begingroup\$ Not sure if it's explicit in 5e, but I recall that the 3.5 PHB describes potions as being 1/2 oz. of liquid. \$\endgroup\$ – Dan Henderson Aug 19 '16 at 15:57
  • 5
    \$\begingroup\$ Experience diver here. The water movement has little to do, unless he's near corals or something he doesn't want to be pushed against. Buoyancy (going up or down) is not something in regard to the action being done either. 95% of the time, divers have their hands doing absolutely nothing. As for drinking, it's doable if you can push air from your lungs into the bottle (with a "air spell" or something? - I'm not a DnD player). If so, you'll be able to sip a few oz, push air, sip a bit more. Not the most fun thing to do, but definitively not "extreme difficult" \$\endgroup\$ – Alexandre Aug 20 '16 at 4:06
  • 6
    \$\begingroup\$ @DanHenderson 1/2 oz? If I were living in that reality, I would stop adventuring and make a living making 1/2 oz wax bottles that the user could just put in their mouth on chomp on. \$\endgroup\$ – n_b Aug 21 '16 at 15:21

The rues of D&D are simple:

  1. The DM describes the environment
  2. The players describe what they want to do
  3. The DM narrates the result of the character's actions


  1. "You are underwater"
  2. "I want to drink a potion"
  3. This is where you're getting stuck

Well, I'm hypothesising that the reason you have a problem is that, on the face of it, you think the player's described action is impossible. The problem is you are moving onto step 3 before step 2 is finished.

Move back to step 2: "OK, explain to me how you can, with one hand, retrieve a potion, open and drink it underwater without it getting out or water getting in." Listen, be convinced and allow it, remain unconvinced and disallow it or get somewhere in the middle and set a DC.


In similar situations in my games (not drinking a potion underwater but other seemingly impossible tasks) I use the "rule of cool" If it sounds like it would be a good story, sod the realism and let it happen. I always go with a DC check that would be considered moderate for the players level.

As for which check? Entirely up to you. Initially DEX sounds like a good one, but the obvious choice. Maybe a Constitution Save to not loose his breath while doing so or some such. If you really feel the need, give the player disadvantage but keep it so the roll is achievable.


Mixing or diluting a potion is not good. You may need to reference other editions for ideas: the effects of mixing and sipping are covered in various places, good sources of ideas for possible effects.

If the person can get the potion bottle to their mouth, make a seal, and pull the cork with teeth and tongue to drink, then it should work.

I would call it a DEX check or two. You will also need to take the depth into consideration, as the increasing pressure would render this more challenging the deeper one is. Unless you have some effect similar to Airy Water available.

As usual, players always manage to come up with a situation not covered in the rules.

  • 1
    \$\begingroup\$ You don't need to go to other editions, 5e DMG p.140 talks about it. \$\endgroup\$ – nitsua60 Sep 12 '16 at 2:22

I assume you are playing in a medieval setting. Most little bottles I have seen from old apothecaries may remain closed under water, but definitely aren't suitable for consuming the content under water (for that you would need an opening where liquid is expelled by force and an elastic bottle). Hence, I suspect, your player's demand us highly unrealistic and immersion breaking. And my gut feeling classifies what he attempts as bordering on the impossible.

enter image description here

However, to be fair, I would let him describe the bottle and his way of handling it in great detail. I just made a few attempts -not under water- with the only (unfortunately larger) bottles I had available. I found it easy to excert a tiny pull by pushing the lips forward and clenching my teeth, while keeping closed lips, but impossible to get a substantial pull.

Perhaps he has a better technique. After his description, you can gauge whether it is impossible or very difficult. In the latter case you can require adapted checks. Upon failed check you may choose to let him drink diluted potion.

If I was game master, I would suggest that he role play it physically (without water). I would not insist on it though. A clumsy player is not required to perform the actions of a nimble elf. He is required to describe them in detail, though.


My assumption was: he shoves the potion between his lips quickly, gulps down a bit of water and then applies his technique for opening bottles with sealed lips, whatever that might be...


If his technique involves leaving the bottle open under water for a short time, as in the accepted answer, the success should vary depending on how empty the bottle is and on how deep under water he is! I assume he is not just marginally under water, else he might want to do it outside the water. He might of course be hiding just below the surface...

  • 3
    \$\begingroup\$ The antique bottles you posted would be difficult to use underwater, mainly due to the width of the neck, but they bear little resemblance to either medieval bottles or the illustrations in the DMG. They look more like bottles you would find in a 19th or early 20th century apothecary. Since most of the potions in the DMG are illustrated, I would tend to let those be the arbiter of the suitability of a bottle, if needed. \$\endgroup\$ – keithcurtis Aug 18 '16 at 22:16
  • \$\begingroup\$ Very good point! @keithcurtis \$\endgroup\$ – Ludi Aug 19 '16 at 6:41

If you're planning to go underwater, you'd better have your potions in small skins that you can squeeze in your mouth. 3.5e had those.

The uncorking (with your teeth if one hand is tied) and the stopping with your thumb could solve opening and not diluting the potion, but the largest problem is that bottles are rigid and air needs to get in for the liquid to get out.

With squeezable containers, that problem stops exisiting.


If the potion user were to get an air bubble (at depth) into the vessel and ascend, the expanding gas would (Boyle's Law) actually force the fluid into the mouth if you left it there (upend the bottle, blow some air in, keep mouth sealed over bottle, swim up). The relative amount of expansion is greatest closer to the surface of a water body - the last 10 meters causes approximately a doubling in volume. Of course, the deeper you go the harder this gets to do (on breath hold), so there would be a limit as to the workable depth of this trick.

I've done plenty of things under water with one hand occupied as a diver.

As others have suggested, flexible containers (like waterskins, or in modern society juice boxes, "capri sun" type foil packed drinks and even plastic bottles) don't suffer from these problems - you can easily squeeze the contents into your mouth with one hand - indeed, tech divers often drink like this on long decompression stops.


If it's a glass bottle - then no. If it's a flexible bottle (plastic) - then yes.

You need to breathe in order to drink. Air needs to flow into the bottle to replace the escaping liquid. So if it's a glass bottle, drinking is unlikely as you'd need to replace the volume of the liquid in the bottle with air (unless they could use the last of the air from their lungs I guess) If it's a squeezable bottle then they can just force the liquid into their mouth.

  • \$\begingroup\$ Not just plastic, but also leather, hypothetically. \$\endgroup\$ – user17995 Aug 17 '16 at 9:58

Come on GM, if you cant imagine it, try it! No need to go underwater :D ..Take a glass bottle(or other bottle that is hard plastic and cant collapse from suction!), fill it up, seal your lips around it, and keep the lips TIGHT.

Try to drink that bottle empty without letting air to enter that bottle. You will be able to drink very very little(about as much as you had air in your mouth), and then it becomes impossible if the bottle cant crush or you wont let air into the bottle. (underwater you could not let air into the bottle because lips need to be sealed tight)

If your players character happens to have his whatever magical juice container made out of like unicorns bladder(or just from some leather or such soft material), then he would be able to drink it, because unicorns bladders are not made from hard plastic or glass and there is no problem with these pressure things then.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.