I'm taking the plunge (pun intended) and having a go at writing my own aquatic based adventure. I intend to use settings of a port, a ship, underwater and a hidden (air and water) cavern.

I've compiled a decent long list of NPCs and Monsters that would work well in these settings, but I'm unsure about the underwater part of the adventure.

What options are available for me to give my characters the ability to breath underwater?

The only things I can think of at the moment are:

  • some kind of magic.
  • some kind of invention (a primitive aqualung)

Does anyone know of any other options that I may be missing?

  • \$\begingroup\$ Are you looking for a list of spells and magic items that give the ability to brethe underwater, or a list of ideas that aren't either some kind of magic or some kind of invention? \$\endgroup\$
    – Miniman
    Jun 10 '16 at 13:55
  • \$\begingroup\$ @Miniman Either or both would be good. Although I also want to be sure I haven't missed anything else. \$\endgroup\$ Jun 10 '16 at 14:01
  • \$\begingroup\$ Questions asking for lists of things don't really work at RPG.se. As a rule they result in a continuous trickle of “oh, and one more…” posts and endless maintenance of existing posts, which eventually stop being maintained and then become incomplete/wrong—the worst of both worlds. What would probably be necessary for this to work as an SE-style Q&A is to work on your adventure and then when you have a specific situation that you are having difficulty solving, ask about that directly. Answering specific questions with specific answers is the strength and mission of RPG.se. \$\endgroup\$ Jun 10 '16 at 17:04

You've basically covered all the bases with "some kind of magic" (ie, all magic) and "some kind of invention" (ie, all technology).

Here's a more fleshed out list for magic (thanks to keithcurtis for providing the latter half of this list):

  1. A potion of water breathing, or a scroll or spell
  2. A polymorph spell or scroll -- turn into sea creatures
  3. A Druid's Wild Shape, if you have a Druid in the party
  4. A control water spell or scroll -- create air bubbles for you to breathe
  5. Cloak of the manta ray
  6. Cap of water breathing
  7. Necklace of adaptation

Here's one for technology

  1. An artificial aqualung, as you said
  2. A series of ports/depots where the aqualungs can be refilled, if this path has been taken by other air breathers before
  3. A comically long snorkel
  4. A primitive submarine (that will most likely kill everybody inside)
  • 4
    \$\begingroup\$ Comically long snorkels would suffocate you, due to your lung capacity probably not being sufficient to push your carbon dioxide out of the snorkel far enough to exhaust it, nor draw fresh air in far enough to ever breathe it. \$\endgroup\$ Jun 10 '16 at 14:03
  • 1
    \$\begingroup\$ But they would provide for a well deserved death. Anyone who thinks they could actually use one is a waste of air, in any case. \$\endgroup\$ Jun 10 '16 at 14:04
  • 2
    \$\begingroup\$ @timstermatic It won't necessarily, actually. Here's the trick: 1- breathe from your snorkel. 2- remove mouth from snorkel, cover snorkel hole. 3- breathe out into the water. 4- repeat. Alternatively, replace steps 2&3 with breathe out from your nose. \$\endgroup\$
    – user27327
    Jun 10 '16 at 14:08
  • 3
    \$\begingroup\$ You could replace tech Nº4 with an apparatus of Kwalish. It can hold 2 medium-size or smaller creatures. \$\endgroup\$ Jun 10 '16 at 15:00
  • 2
    \$\begingroup\$ There's a few magic items missing, cloak of the manta ray, cap of water breathing and necklace of adaptation will all allow breathing underwater. \$\endgroup\$
    – yinzanat
    Jun 10 '16 at 15:17

Some past editions had Sea Elves who could breath underwater. You could do an aquatic races only game. Just an option.

  • \$\begingroup\$ the Sword Coast Adventurer's Guide has an aquatic elf, I believe. (I don't own it or I'd edit in a mention.) If true, this canonical 5e course would certainly be good to mention. \$\endgroup\$
    – nitsua60
    Jun 10 '16 at 16:17

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