Recently an article was published regarding Spelljammer and what items or races could be used to survive in the airless confines of realm space. Amongst the items, the Necklace of Adaptation was not listed. The item allows you to be able to breathe in any environment, so wouldn’t that allow you to survive in the airless parts of space?

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    \$\begingroup\$ Welcome to RPG.SE! Take the tour if you haven't already, and check out the help center for more guidance. You mention Spelljammer so this is about D&D, but what edition are you asking about? Do you have a link to this "recent article"? (I'm guessing it's about D&D 5th edition; is that correct?) \$\endgroup\$
    – V2Blast
    Aug 4, 2022 at 17:19
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    \$\begingroup\$ Are you talking about this article from DND Beyond: Building Your Character to Survive Spelljammer Adventures? \$\endgroup\$ Aug 4, 2022 at 17:22
  • \$\begingroup\$ I've added the [dnd-5e] due to the recent publishing of the article mentioned above, and the upcoming Spelljammer setting for D&D 5e. \$\endgroup\$ Aug 4, 2022 at 20:56

3 Answers 3


A Necklace of Adaptation does, indeed, allow the wearer to "breathe normally in any environment". This GM sees no reason to believe that it wouldn't allow the wearer to breathe normally in the airless parts of space (or airless parts of planets; ie., under water), nor can I see an interpretation that would preclude its use.

My supposition is that the necklace is a well-known item (it exists at least as far back as 3.5, which is where I started playing); as such, it's a fairly obvious solution - for players with a high degree of system expertise - to the "airless" problem. It's also a straightforward solution where the article, if Thomas Markov's comment is correct, focuses on less-obvious options (a friendly plant creature, petrification, and a very slightly cheeky reading of how a cap of waterbreathing and a bucket of water interact). That is: the list isn't meant to be exhaustive, but to remind players that there are options other than "play a race that doesn't need to breathe" and to think outside the box for those solutions.

... says the player rocking a 3pp not-quite-Warforged in a Spelljammer campaign that's just started, not least because of the whole "doesn't need to breathe" thing they get ...

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    \$\begingroup\$ The Necklace seems to have originated in AD&D1e, where its description says "... even exist in airless space for up to 7 days." \$\endgroup\$ Aug 4, 2022 at 22:38
  • \$\begingroup\$ It's confusing that it says "you have advantage on saving throws made against harmful gases and vapors"; shouldn't wearers have full-immunity to those things already? I mean, those sound like some of the mildest hazards. \$\endgroup\$
    – Nat
    Aug 5, 2022 at 8:58
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    \$\begingroup\$ @Nat: that could be a whole 'nother question. But: real-world, it works that way because that's the way it says it works; in-universe, perhaps the magic mixes the air from the environment into the bubble, allowing the wearer to smell (and be smelled!), but also allowing a lower-concentration dose of the gases and vapors in. \$\endgroup\$
    – minnmass
    Aug 5, 2022 at 13:00

Technically, you're never exposed to vacuum in Spelljammer.

In Spelljammer, objects in space hold an envelope of air around them, and the size of the envelope is based on the mass of the object. That's how you can have spelljammer ships that aren't airtight; the air just sort of sticks to them.

The same holds for a creature that falls off a ship. They take a little bubble of air with them, and if not rescued, the air will become unbreathable in a short time. They'll eventually suffocate, but the body will still have a little cloud of what the rules refer to as "foul" or "deadly" air (but what we would call carbon dioxide) around it. I'm sure there are extraordinary circumstances where the normal rules don't apply and you can end up out in raw vacuum, but that's not how it generally works.

Under normal circumstances, whether a necklace of adaptation would work in the void of space just doesn't matter, because it would be the bubble of increasingly foul air around you that it allows you to continue to breathe without ill effects.

  • \$\begingroup\$ Why would the air become "foul" by breathing it? All that would happen is that the concentration of carbon dioxide would raise \$\endgroup\$
    – AnnaAG
    Aug 5, 2022 at 8:49
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    \$\begingroup\$ @AnnaAG I imagine that's what DP means by "foul" - in the context of caving, foul air is any air that has a too-high concentration of carbon dioxide (or other unbreathable gasses) or a too-low concentration of oxygen. It doesn't matter if it smells bad; in fact, that's worse because you may not realise the air is dangerous until it's too late to escape it. \$\endgroup\$ Aug 5, 2022 at 10:16
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    \$\begingroup\$ In 2e Spelljammer, and I assume in the 5e version (haven't read it yet), 'foul' is the term they use for air that's all breathed out. Yes, we're talking about carbon dioxide poisoning but mentioning specific chemical gasses isn't appropriate for what is still a quasi-medieval milieu, so the term is 'foul air'. \$\endgroup\$ Aug 5, 2022 at 12:45

It works in water, where there's effectively no gas (for lung creatures, versus gill creatures). It works in cloud kill. It's magic. I can't imagine CO2 is somehow worse than cloud kill (unless CO2 IS cloud kill).

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    \$\begingroup\$ Where did CO2 come into this? The question is whether it will let you survive in a vacuum. \$\endgroup\$
    – Oblivious Sage
    Nov 6, 2023 at 21:37

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