An Easy Guide to How How Drowning Works in D&D 5e

Dungeons & Dragons 5^th Edition often presents magical and fantastical dangers to player characters. But sometimes, the more mundane hazards are the more dangerous. Drowning is one such hazard that can even challenge higher level player characters. That said, the rules around drowning can be a bit confusing.
 
How does drowning work in 5e? When do player characters start drowning? And, how can a Game Master use the threat of drowning in their games?
 
This article covers everything you need to understand the rules for drowning in D&D 5e.

Let’s start with the explicit rules for drowning in the Player’s Handbook.

How Drowning Works in D&D 5e

Drowning in 5e works through the suffocation rules. Essentially, a creature in 5e either survives a number of rounds based on their Constitution modifier before it starts dying due to drowning.

Basically, drowning in 5e works the same way as suffocating. This means a creature starts to drown once they run out of air or start getting choked. Once that happens, they can survive a number of rounds equal to their Constitution modifier, dropping to 0 hit points and dying once that time runs out.

This all comes from the rules on suffocating from Chapter 8 of the Player’s Handbook:

First off, any creature survives at least 1 round (or 6 seconds) once they start drowning. This gives them at least 1 more action to maybe get more air or swim to the surface. So, creatures with a negative Constitution modifier don’t start dying immediately even once they start drowning.

The amount of time they can survive at this point equals their Constitution modifier. Every Constitution modifier from -5 to +1 (scores of 1 to 13) gives a creature 1 round of survival once they start drowning, but higher scores means lengthier amounts of time.

Basically, how long a creature can survive once they start drowning follows these Constitution Ability Scores:

• Scores 1 to 13 (-5 to +1 modifiers): 1 round (6 seconds)
• Scores 14 & 15 (+2 modifier): 2 rounds (12 seconds)
• Scores 16 & 17 (+3 modifier): 3 rounds (18 seconds)
• Scores 18 & 19 (+4 modifier): 4 rounds (24 seconds)
• Score 20 (+5 modifier): 5 rounds (30 seconds)

Remember: 1 combat round in D&D 5e equals 6 seconds real-time. That’s why the actual time in seconds is included since drowning in 5e often happens outside of combat encounters.

Once a creature runs out, a creature drops to 0 hit points and is dying. This means they start making death saving throws or simply die for most non-player characters but they can’t become stable until they can breathe.

How Long a Character Can Hold Their Breath Underwater

Every creature in D&D 5e, including player characters, can hold its breath for at least 30 seconds if given time to prepare. Beyond that, how long a character can hold their breath relies on their Constitution modifier plus a base time of 1 minute.

The rules for how long a player character (or any creature, for that matter) come from Chapter 8 of the Player’s Handbook:

So, every creature that needs to breathe can hold their breath for a minimum of 30 seconds (or 5 rounds). This means creatures with a negative Constitution modifier don’t lose all ability to hold their breath at all. Beyond that,

But, the higher a creature’s Constitution score, the longer they can hold their breath.

• Scores 1 to 9 (-5 to -1 modifiers): 30 seconds (5 rounds)
• Scores 10 & 11 (+0 modifier): 1 minute (10 rounds)
• Scores 12 & 13 (+1 modifier): 2 minutes (20 rounds)
• Scores 14 & 15 (+2 modifier): 3 minutes (30 rounds)
• Scores 16 & 17 (+3 modifier): 4 minutes (40 rounds)
• Scores 18 & 19 (+4 modifier): 5 minutes (50 rounds)
• Scores 20 (+5 modifier): 6 minutes (60 rounds)

So, no matter a player characters Constitution modifier, they’ll be able to hold their breath for at least 30 seconds or 5 combat rounds.

Of course, a creature may lose their breath for a variety of reasons. Casting a spell which requires a Verbal component means expelling held breath, so a spellcaster needs to carefully choose which spell to cast while underwater. Likewise, knocking a creature unconscious through any means (dealing damage or through an ability or spell like sleep) probably means they can’t hold their breath anymore.

Drowning During Combat in 5e

The rules for suffocating explicitly call out how many rounds a creature survives once they run out of air. As such, drowning during combat in 5e is specifically centered around how many rounds a creature can survive. However, the rules for holding breath are counted in minutes (or seconds), which means you need to convert a round into 6 seconds to know how that works during a combat encounter.

Honestly, there’s a weird disconnect between how long a creature can survive once they start drowning (measured in seconds) as opposed to how long they can hold their breath (measured in rounds). So, both players and Game Masters need to understand 1 combat round equals 6 seconds. It’s an easy conversion but you need to understand it from the start or you might run into confusion when a creature starts drowning during combat.

With that in mind, combat in 5e is usually measured in rounds, not seconds. So, you should understand how long a creature survives once they start drowning in rounds. What’s more, assuming a creature is prepared to go underwater, how long they can stay submerged before drowning is a combination of how long they can hold their breath and how long they can survive after.

For example, a Barbarian with a 16 Constitution score (+3 modifier) can hold their breath for 4 minutes or 40 combat rounds. Once they run out of air, they then have 18 seconds or 3 rounds before they drown. After running out of breath and staying underwater for this amount of time, the Barbarian automatically drops to 0 hit points and making a death save every round. That said, they won’t stabilize even if they succeed on 3 saves or roll a natural 20. They first need to be able to breathe again.

Of course, combat encounters in 5e rarely last that long, but this was just an example to show how drowning during combat works.

How Drowning Affects Death Saves

Drowning affects death saving throws in the same way suffocation ordinarily does; a creature starts making death saves after running out of air (either due to surprise or running out how long it can hold its breath) but they won’t stabilize even after succeeding 3 times. Essentially, a creature will eventually die while drowning in 5e because they can’t stabilize until their become able to breathe again.

Death saves have already been lightly touched on, but I wanted to go into a bit more detail because death saves and drowning in 5e have some weird interactions.

So, the rules for suffocating (i.e., drowning) in 5e state a creature that drops to 0 hit points starts "dying, and it can’t regain hit points or be stabilized until it can breathe again."

Breaking this down, when a creature starts dying due to drowning in 5e, they start making death saving throws as usual. However, the rules get modified in that even if you succeed on 3 death saves (which ordinarily stabilizes a character) or you roll a natural 20 (which typically stabilizes a character and gives them 1 hit point), a character won’t stabilize or regain hit points. The rules explicitly state this which tracks since the reason that character started dying in the first place was because they couldn’t breathe.

So, just from a pure probability standpoint, a player character WILL die from drowning since they won’t stabilize from successes and they’ll eventually fail 3 death saves. That is, unless you’re ridiculously lucky and never roll below a 10.

Spells that stabilize or heal creatures like spare the dying or healing word won’t help a drowning creature.

To stabilize a creature that’s drowning, that creature first needs to be able to breathe again. This means taking them out of the water or casting a spell like water breathing or air bubble from the new Spelljammer: Adventures in Space sourcebook. Once they can breathe again, then you can stabilize or heal a drowned creature.

Using the Threat of Drowning in Your 5e Game

Drowning is a mundane hazard that even high-level player characters should fear. There are few ways of avoiding it once it starts happening and even those methods have their own counters. As such, the threat of drowning in 5e is a good obstacle Game Masters can use to challenge their players.

Here’s the thing: there are very few ways to prevent or stop a player character from drowning in 5e. As such, it’s a very real threat for characters of any level.

Of course, there are extremely useful spells like water breathing and air bubble players have at there disposal. But, since they’re spells, dispel magic or an antimagic field remove these effects.

What’s more, once a creature starts drowning, healing doesn’t help them until they can breathe again. This means player characters need to go out of their way to take a fallen party member or ally out of the water which is a challenge in its own right.

This all means that drowning in 5e is a fantastic obstacle to present before your players.

Some examples of introducing water as an obstacle and drowning as a threat include:

• Parts of the villain’s hideout are submerged underwater
• Water-dwelling monsters are raiding fishing and trading vessels
• The ancient dungeon once used water as an emergency method for dealing with an escapee
• A portal to the elemental plane of water is opened by cultists, flooding their compound
• An enemy faction destroys a dam holding back a massive lake above a town
• The party’s sailing ship gets attacked from a hostile creature or creatures, threatening to sink their vessel

These all present the dangers of water and the threat of drowning clearly before the player characters.

If you want to make drowning more in-line with other mechanics, you may treat it like concentration. Now, I wouldn’t say a creature actually concentrates on holding their breath; that would interfere with actual concentration for the purposes of spellcasting. But, use the same rules for taking damage or experiencing an extreme situation and resisting breathing out as a result. Maybe a creature loses a minute of air when they fail rather than all of their held breath.

Bear in mind; this is a homebrew rule. It’s not in the rules but may make the danger of engaging in combat underwater more apparent.

5e Drowning FAQ

Summary of Drowning Rules in D&D 5e

That covers everything you should need to know about drowning in 5e.

Drowning uses the same rules for suffocation in D&D. A creature starts drowning once they run out of held breath or are unprepared to lose their ability to breathe.

How often do you use the threat of drowning as a Game Master in your 5e game? As a player, do you often prepare spells or keep your character prepared for the possibility of drowning? Leave a comment below to share your thoughts!

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