Can the Purify Food and Drink spell make ocean/sea water drinkable?

Question

As the title says, can the spell purify food and drink make ocean water clean and drinkable?

The spell says:

All nonmagical food and drink within a 5-foot-radius sphere centered on a point of your choice within range is purified and rendered free of poison and disease.

Some in my group say you would purify the water, therefore it is drinkable, absent of salt. But others in my group argue that salt is not inherently bad, so while the spell may remove the impurities along with other poisons/diseases from ocean water, it wouldn't remove the salt.

Someone else brought up the argument that, for example, if someone had a cup of some juice, which would have a little bit of salt, the spell wouldn't have removed the salt then. Or what if someone was cooking and accidentally spilled extra salt in it - would the spell have removed the salt then?

So would the spell make ocean water clean and drinkable (RAW)?

Answer 1

The RAW is not clear enough. Unless you are an overly technical GM or player, stick to the spirit of the spell.

I believe the spirit of the spell is to render normally dangerous or unpalatable food and drink safe for consumption.

In that regard, seawater would make you sick. Once purified it would no longer do so since the impurifications like salt, sand and micro organisms would have been magically removed.

This would also mean casting it on rotting flesh makes it safe to eat (including any diseases the maggots and insects currently feasting on it may carry), and casting it on alcohol it would become plain water since I would consider alcohol a type of poison (sluggish thought and movement, dehydration, nausea and vomiting, all signs of being poisoned).

Answer 2

The spell would remove the salt from water, but only if the plan is to drink the water.

This answer doesn't rely on any other 5e rules aside using common terms in English when there is no specific game feature using that term. The spell states (emphasis mine),

All nonmagical food and drink within a 5-foot-radius sphere centered on a point of your choice within range is purified and rendered free of poison and disease.

As being purified is not a game term, we must rely on the actual term. Wikipedia has a page for "Water purification" that states,

Most water is purified and disinfected for human consumption (drinking water), but water purification may also be carried out for a variety of other purposes

So as long as your reason for casting the spell is to make the water drinkable, the salt will be removed from it.

Answer 3

I don't think the rules are explicit about this case. You will need a DM ruling.

That ruling might be "it is always made into drinking water, because you are purifying the water", "it is never made into drinking water because you are purifying the salt water as a whole", or even "it depends on what you want the spell to do".

First, the spell, as quoted, purifies and removes poison or disease from its target(s). I assume from your description we are talking about "ordinary" salt water, so we can ignore the poison and disease part. So we are left to consider whether "purification" would remove the salt from the water.

I don't believe this is quite straightforward; purifying "water" could easily be argued to include removing salt (and anything else needed) to leave you with as ordinary drinking water. However, if you might also argue the spell is purifying the "salt water" as a whole, as thus wouldn't remove the salt (but may remove any other things consider "impurities"). As a result I think you'd need the DM to decide.

Additionally, the spell works only on "food or drink", and salt water is clearly not "food". So the question remains whether salt water is a "drink". I could see an argument (though I wouldn't advance it myself) that salt water isn't a "drink" and so the spell doesn't affect it at all. Your DM might subscribe to that argument or not, so you'll need their opinion.

Personally, I would argue that the spell ought to render the water drinkable, and thus would remove the salt. However, you may want to set some limit on how far this goes; perhaps swamp water could be purified, but would you allow a clump of mud to be "purified" to leave only the water? The spell text doesn't address any of this so you will need to clarify with the DM, as they are the final arbiter of what a spell does.

Answer 4

I think this is one for your DM to decide on, but personally I would allow it. Mainly because of the RAI functionality of this spell. If I was playing myself in a swamp with plenty of putrid water, I would expect that gathering some water into a bowl or skin and casting Purify Food and Drink would indeed purify it - making it drinkable. In the same way salt in seawater is poison because of its high concentration, so arguably casting Purify Food and Drink will remove excess salt, as well as any other nasties which might be in the water you didn't know about. On a side note, you could gather some seaweed or sea kelp and purify that, too, for an ocean snack.

Alternatively, if it is just the drinkable water you are after, you could use a different L1 spell instead: Create or Destroy Water. This would give you and your party 10 gallons of drinkable water.

I hope this helps.

DM Tortoyse

Answer 5

Sea water is not a drink and salt is not a poison.

There is no 100% unambiguously correct answer to your question because neither the game's rules nor the spell give an exhaustive definition for what counts as food, drink, poison or disease. The spell's effect hinges on the common, everyday English definitions of those words and the context in which they're used.

Remember, the spell never claims to make all kinds of liquid drinkable; it removes poison and disease from drinks. This poses two problems: sea water isn't typically considered a drink (you wouldn't offer it to a guest or find it served in a restaurant) and salt isn't typically considered a poison (it's even beneficial if you don't overdose on it.)

Salt water as a whole could be considered a poison since drinking it always does more harm than good, but you'd have to first consider salt water to be a drink, and purifying something that's 100% poison by volume would presumably leave you with nothing anyways.

In my opinion it's clear that the spell takes something you would normally eat or drink and remove concentrated poisons or foodborne illnesses. It's not going to extract food or drink out of something that's not edible in its current form.

Answer 6

RAW, it's unclear.

Allowing the spell to be used this way makes good logical sense, but introduces additional questions which the DM will have to resolve, and are definitely not covered by RAW at all, and so will have to be resolved arbitrarily.

There's enough discussion on most of the surrounding issues, and this is a relatively late answer anyhow, so I won't spend a lot of time on preamble. The reasons it may not work, in descending order of relevance:

1. Spells do what they say they do/there are no secret rules. The water has to be food and/or drink, for which salt water can qualify well enough. But the spell description clearly states that it renders its target

   [...] is purified and rendered free of poison and disease.

   Salt is not, in itself, a poison or disease, despite other answers on this question suggesting that salt in water is a poison. RAW, which this question asks for, is pretty definitive on that point. The single most important element of this classification is that Poison is a distinct, defined term in D&D which does not map easily to real-world, colloquial uses of the word poison. Salt exists in D&D (as a trade good), and is not described as a poison or disease.

   There is poison damage; Poison, Basic; Drow Poison; Purple Worm Poison; Wyvern Poison; Potion of Poison; and spells like Poison Spray; Detect Poison and Disease; Protection from Poison and more. Considering salt, in water or elsewhere, as being equivalent to the named poisons and poison effects, or a suitable target/piece of information to gain from spells is a stretch. Would casting Detect Poison and Disease while in the ocean reveal the ocean itself as poisonous? Perhaps, if your DM is so inclined, but I think that would be unusual. Would casting Protection from Poison render saltwater drinkable? From the description of that spell, explicitly no.

   Pure is not a defined game-mechanical term, and so is omitted from this point. It is addressed below, in (2).

2. Even if you find (1) unpersuasive, resorting to using common definitions of words doesn't help a whole lot here. Many existing answers have focused on the word purify, but do so a bit inconsistently. Purify does not suggest reduce to a single molecular chemical (dihydrogen monoxide, in this case)-- if that were the case, using the spell on something like beef would be impossible. Most foods are very complex combinations of molecules, and if you want to use the spell to purify anything organic (which it is clearly intended to do, as it's about food as well as drink) then purity becomes a largely undefined term, which is particularly difficult in this case: if you can have a "pure" apple or "pure" honey, you can have a volume of "pure" saltwater.

3. There is nothing in the description of the spell that suggests it necessarily makes food and drink safe for you or anyone in particular, specifically, only that it removes foreign elements defined as poison and disease. There are berries which are safe for birds to eat but very poisonous to humans. The berries are already "pure", in that they are what they naturally are. So if a bird (or Kenku, if you will) were to cast this spell on such a berry, would the poisonous-to-humans-but-not-birds elements of it remain? If an underwater-dwelling, marine creature (read as: does not need to consume fresh water directly) were to cast it on an acceptable volume of water, would that remove the salt from it?

   If a character were attacked by a giant centipede and poisoned, would this spell work on it? The centipede may well view the character as food, and can inflict the Poisoned status. A looser definition of the terms used in the spell description make answers to these sorts of questions less clear.

4. Whether or not you find (1), (2), or (3) persuasive, applications of this spell which allow one to remove salt from water raises more questions than it answers. Degrees of salinity aren't simulated in D&D, but plenty of water contains solutes that aren't harmful. As a thought exercise, would this spell remove fluoride from fluorinated water? It's safe (again, in appropriate concentrations), and indeed makes water "healthier". Anyone's answer to that is irrelevant to this question, but allowing this spell to selectively remove some elements under some circumstances and not others under other circumstances is very much not what the text of the spell outlines. The interpretation, very sensible in this case, raises additional edge cases which will require decision.

   Safely drinkable is not the same as totally pure and clean. Some have argued that enough salt in water is a poison, to some. Even ignoring (3), above, that statement is true of basically everything. Water intoxication is a real thing, though you have to drink a lot of water to suffer from it. Few would argue that this means the spell would make water disappear entirely because it could, under some conditions, be injurious, nor that it would reduce the amount of water present to a quantity small enough that water intoxication would be impossible.

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Sure it does, if you want. But RAW may not be the best basis for arguing that it definitely should.

There are lots of sensible extensions and house rules that could be applied to make this spell a bit more expansive, and I would almost certainly allow the spell to convert undrinkable salt water into potable water at my table. But RAW, by definition, doesn't extend beyond the text itself into sensible interpretations or better mechanics.

Expanding this spell beyond removing poisons and diseases is straightforward enough. The purity bit, though, not only isn't RAW in itself but also requires additional house rules, homebrew mechanics, and interpretations beyond what's written in order to produce a consistent set of adjudications. Again, this is totally, 100% fine and possibly even recommended for a given game.

Answer 7

All things are poison, and nothing is without poison, the dosage alone makes it so a thing is not a poison.
— Paracelsus (Septem Defensiones, 1538)

Everything is a poison, if ingested in the right dosage. Purifying something means removing enough so that what remains can be safely ingested.

Hell, even distilled water is toxic in large doses, as it is hypotonic.

I don't see why the spell would remove some contaminants that are poisonous in certain doses, and would leave the others. In my opinion, it would reduce the salt to safe levels just like it would other contaminants.

Some people argue that salt water / sea water isn't a drink. That's a non-sequitur. No kind of poisonous water is a drink. But the spell takes unsafe water and makes it safe for consumption. Sea water is water that is unsafe for consumption, so it makes it safe for consumption.

In the light of the quote above, treating salt differently from other contaminants is, in my opinion, not justifiable.

Answer 8

In the context of potable water, I had never heard anyone insist that seawater was not "tainted water" until 50 seconds ago when reading the comments and questions on this very SE question.

Asked in any other context, practically everyone would agree seawater would be a drink if it weren't tainted, and would be again if it were purified.

TL;DR: Yes, sea-water can be purified with the spell. The onus of burden is on others to argue otherwise.

Is your game's magic a beneficial supernatural force or a trickster genie?

Many people have drank sea water before. I have. Many people would love to drink it all the time, "If only I could purify it!" they would say. This is exactly what the spell seems to be expressing.

So when your mages cast spells, do you let them have the intended effects that they rightfully expect? Or is your magic system like that of a trickster genie who puts someone in a safe prison for eternity when they wish that nothing could ever physically hurt them again, fulfilling the wish only on a technicality?

Some people like thinking of magic this way, but if you want that you should discuss it with your group.

I once read of someone using freedom of movement spell, and while it was still active they jumped into the water to get away... DM stated the PC fell to the bottom of the ocean. If magic is not discussed that way ahead of time, that's way uncool.

But if you want to get nit-picky...

Most things are not poisonous in moderation (or are even good for you), and most things are poisonous in too large of a quantity. Iron, copper, vitamins, minerals, WD40, antifreeze, etc., etc.. A drink containing all of these would still be a drink if they were all present in extremely small amounts. Increase the amount of any single thing and eventually it will be poison, even in the case of some vitamins and minerals.

What the spell actually does

Let's just take the spell at face value. The following statement is directly within the spell's wording and therefore is not up for debate: All drink is purified.

"Is water a drink?" That's a given.

Water is a drink, this spell purifies drinks of which water is one, so it purifies water.

Anyone who argues "Water is a drink, but sea-water is not!" has just rendered the spell useless. Water is a drink, but poisoned-water is not, so by that logic the spell doesn't work on poisoned drinks. Diseased water is not a drink, poisoned or diseased food is no longer food, so this spell works on none of them... we just rendered the spell completely and utterly useless.

Trying to be an obnoxious rules lawyer simply does not work in this case. The spell does exactly what it says it does.

Possible Alternate Interpretations

I can think of a few interpretations which could change this, but they would all require assumptions not stated in the spell.

For example, one could argue "a container full of nothing but poison, which contains no water molecules at all, but which much later on has had enough hydrogen+oxygen atoms combine to form water within it that there are trace amounts of water, is obviously not a drink. This answer suggests it is a drink just because there is water present."

Since "a cup of drinking water with a few drops of potent poison added" is obviously what this spell was intended for, the absurd extreme of "a container with trace amounts of water" could be perceived as a challenge. There are several ways to look at it:

1. Was it initially intended to be a drink?

Water+poison: yes, it works. Poison+water: no, it doesn't work.

This option requires the magic to know of the previous state and/or location of the bits of matter that make up the fluid or object. Whether this should be a criteria should be based on house rules, not RAW rules-lawyering.

2. Is there enough water to be considered a drink?

Water+poison: yes. Poison+water: no.

Whether there is a percentage cut-off to "How much poison before it's just considered a pile of poison instead of food or drink?", and if so what that percentage should be, should be based on house rules rather than RAW rules-lawyering.

3. Does it contain any amount of drink in it?

Water+poison: yes. Poison+water: yes.

Resolves the situation easily but cannot be considered part of the RAW reading as it would let the spell do things it obviously wasn't intended to do. Example: there's a barrel of poison enemies are going to dump into the lake to pollute the whole area, but you just pour a few drops of water into the barrel and cast the spell - does all that poison simply disappear because of the few drops of water?

Interesting implications, maybe you want them, but it would be based on house rules.

Summary

Yes, it works on sea-water.

When your players try to take advantage of this when they enter a salt mine with a leaky ceiling and they want to turn the slop on the floor that is 70% salt and 30% water into pure drinking water, then go ahead and revisit the issue. But note that even then it's not a RAW rules-lawyering issue but instead is a subjective house-rule issue.

There are corner cases, as mentioned in my previous section, where the spell becomes tricky to judge. But the specific case in your question is not one of them. People generally consider sea-water to be a liquid that they would drink if it were purified to remove the risk of salt-poisoning. The spell says it purifies drinks.

Unless a compelling argument is made to the contrary this would be the default reading.

Answer 9

We need stats for salt water first, before we can proceed.

Every analysis of purify food and drink targeting salt water needs to start with the text of purify food and drink and with the text of salt water. Herein lies the problem: we do not, to the best of my knowledge, have stats for salt water. Since we do not have that text, we cannot analyze it, and that makes it impossible to offer a RAW answer. This is vastly more important than the much-argued definition of “purified.” Several answers have already asserted various properties about a hypothetical salt water item, but none of them, that I can tell, have noted and highlighted the fundamental problem that we don’t have stats for it and can only assert our own preferred statting of it.

To my mind, though, if you were going to write up the effects of ingesting salt water, you would look to existing rules to mirror. In this case, “ingestion” is a pretty key part of the puzzle—not much of the game deals with that. How does the game model things that have negative effects when ingested? As poisons. To my mind, the most natural way to model salt water, at least for the purposes of ingesting it, is as a poison. After all, sodium chloride is a mineral, which when dissolved in water and drunk, causes harm to the body. That description also precisely describes arsenic.

And as we know, purify food and drink causes the target to be “rendered free of poison.”

This isn’t really an answer to the question, though—because salt water is not officially poison. Salt water is not officially anything. Any particular stats for salt water you like are equally-valid, RAW, as mine. I think mine has a pretty compelling argument for it, but I don’t publish D&D.

So the answer still remains: It depends what stats you are using for salt water.