Suffocation and Surprise

[Levism84]

In the PHB, it states a creature can hold its breath for a number of minutes equal to 1 + its Constitution modifier (minimum of 30 seconds). Is that for any instance of it holding its breath or just when it makes the conscious choice to take a deep breath before holding its breath?

For instance, if a character was going to dive into a body of water, I could see them taking a quick breath before diving in, allowing them to hold their breath for 1 + Constitution modifier in minutes (minimum 30 seconds). However, if they were knocked into the water, unaware they were going to need to hold their breath, would they still be able to hold it that long? Likewise, if a creature was surprised by a strangler who began choking them, would the still be able to hold their breath for 1 + Constitution modifier in minutes before suffocating?

I was just curious.

[MrStabby]

So I always assumed that was the conscious side of things and was an upper limit. Taking someone by surprise would shorten it. The person holding their breath exerting themselves would shorten it. Grappling or squeezing the air out of someone would shorten it.

I have always played it by ear, but a rule of thumb of shortening the breath holding by 30 seconds for each action taken, 15 seconds for each bonus action, each reaction and 15 seconds for each full movement allowance used would seem reasonable to me.

[burninatortrog]

Whether the creature is prepared or surprised doesn't make any difference.

[ruy343]

There is no rule for this in the handbooks as they stand.

However, were I the DM, I would rule that the creature doing the strangling would have a Strength vs. Constitution contest against the target. If the Stranglee fails 3 times before the grapple ends, they fall unconscious.

Regarding falling into water or otherwise being unable to breathe, I would ask each player to make a constitution saving throw (since saving throws are supposed to represent snap decision making and luck). I would grant each player a number of rounds equal to the result they rolled before they fall unconscious and begin suffocating.

[Mellack]

5e doesn't lend itself to the kind of detailed rules you seem to be looking for. It is designed for a quick and easy play, so just the one basic rule. Having to determine lots of different conditions for suffocation would slow down the game too much, IMO.

[MaxWilson]

5e doesn't lend itself to the kind of detailed rules you seem to be looking for. It is designed for a quick and easy play, so just the one basic rule. Having to determine lots of different conditions for suffocation would slow down the game too much, IMO.

5E is designed to be the hacker's edition of D&D, kind of a spiritual successor to 2nd edition in that regard, so if you WANT more complicated and realistic suffocation rules, you should feel free to introduce them. I guarantee you that any changes you make to suffocation will be less intrusive and less complicated than other changes that the DMG encourages, like plugging in a whole new initiative system (with consequent impact on spell durations, PC capstones, feat balance, etc.).

A really simple fix would be to say, "If you're submerged involuntarily, you have no air and are already starting to black out, and you skip the 1+Con minutes stuff and go straight to the 1+Con rounds part." As with all house rules, make sure you get appropriate buy-in from the stakeholders, whether that means "only the DM makes the rules at my table" or "we set the rules collectively as a group and the DM just runs the world and the NPCs."