The Constitution ability (PHB 177) lists tasks like the following, in which the DM might ask for Constitution checks:

  • Hold your breath

  • March or labor for hours without rest

  • Go without sleep

  • Survive without food or water

  • Quaff and entire stein of ale in one go

But the 1st, 2nd, and 4th instances actually have specific rules that ask for saving throws, not ability checks. For example, the second bullet states "March or labor for hours without rest," but there are rules for Forced March (PHB 181). Those rules state that you can march for 8 hours at a slow/normal/fast pace, and then must make a DC 11 Constitution save on the 9th hour of marching, DC 12 on the 10th hour of marching, etc., or take 1 level of exhaustion.

Meanwhile, the 4th bullet point, surviving without food or water, is detailed in PHB 185. A character can go without food for a number of days equal to 3 + their Con modifier and automatically take one level of exhaustion (no save) per day beyond that, and they can go with only half their water requirements if they make a DC 15 Con save per day, or otherwise take 1 level of exhaustion.

So, if I wanted to ask a character who is going to labor for hours without rest to make some kind of roll, should I ask for a Constitution check or a Constitution save? How should the two be separated/chosen from?

  • \$\begingroup\$ Note that with the addition of the optional rules in Xanathar's Guide to Everything, going without sleep also now has rules covering it - that also do not rely on Con checks. \$\endgroup\$
    – Kirt
    Commented Jan 10 at 16:35

2 Answers 2


I think that part you quoted only tries to highlight what kind of situations would you use Con. In 5e the difference between a save and a check is only what you get the proficiency from, so we can forgive their blurring of the lines here.

Also the sentence before the part you quote reads:

The DM might call for a Constitution check when you try to accomplish tasks like the following: (emphasis mine)

So it is left up to the DM and is not a "strict rule".

On whether to call for a check or a save:

The DM calls for an ability check when a character or monster attempts an action (other than an attack) that has a chance of failure. (PHB 174)

You don't normally decide to make a saving throw; you are forced to make one because your character or monster is at risk of harm. (PHB 179)

The DM should ask for a check when the character is doing something actively, this will also usually take one or more actions to accomplish. Saves on the other hand do not take up an action (not even a reaction) and are the result of external forces acting on the character.

So if you would rule that it takes action(s) to accomplish something, it is a check. If it does not, it is a save.

Example: holding your breath. Even though the character can deliberately try to hold their breath, they are not doing it actively: it would not cost them an action to do it. They could force open an underwater door (which definitely takes an action) while at the same time holding their breath. Also, the external force of the need of air forces the roll.

  • \$\begingroup\$ Comments are not for extended discussion; this conversation has been moved to chat. \$\endgroup\$
    – V2Blast
    Commented Jun 22, 2019 at 4:47
  • \$\begingroup\$ @Kirt one free object interaction is a specific exception. Subsequent flask would require an action to retrieve. \$\endgroup\$
    – Mołot
    Commented Jan 11 at 9:35
  • \$\begingroup\$ @Mołot Szega is reading "The DM calls for an ability check when a character or monster attempts an action (other than an attack) that has a chance of failure" and interpreting that to mean 'if you spend an Action, it is an ability check, if you don't spend an Action, it is a save'. I don't think that is correct. If I attempt to jump over a ravine, that could be an Athletics check as part of my movement. It doesn't become a save just because I haven't spent an Action on it. \$\endgroup\$
    – Kirt
    Commented Jan 11 at 18:11
  • \$\begingroup\$ @Mołot As part of this, Szega is saying that ability checks are for things you do 'actively' and appears to be claiming that 'actively' is the same thing as spending an action on something, which appears to be a novel use of the word as a game term (and in my opinion, unjustified). I was pointing out that pulling out a flask meets the standard English use of 'active' but does not cost an Action. That is a minor point, though - what is important is the claim that ability checks are different from saves because checks use Actions - and I think that claim is false. \$\endgroup\$
    – Kirt
    Commented Jan 11 at 18:14
  • 1
    \$\begingroup\$ @Kirt I have to admit that my wording is not the best tbh. As you say, "activeness" is a better indicator than taking an Action. But still, things that take no action can be ambiguous. Is balancing on a beam Acrobatics or a Dex save? Not sure if I should be making major revisions to a 7 year old answer, though. \$\endgroup\$
    – Szega
    Commented Jan 12 at 22:59

Attempts to achieve vs. attempts to avoid

The list of examples of things covered by Con checks is indeed confusing, because of the six things (counting food and water separately), it seems like four of them are are addressed by additional rules in the PHB that don't call for Con checks, while another one (going without sleep) is similarly covered by the optional rules in XGtE. So are Con checks really reserved just for drinking alcohol quickly?

Szega's answer is a great start to understanding the differences between checks and saves, and they begin by citing the relevant rules:

The DM calls for an ability check when a character or monster attempts an action (other than an attack) that has a chance of failure. (PHB 174)

You don't normally decide to make a saving throw; you are forced to make one because your character or monster is at risk of harm. (PHB 179)

Szega also makes a great point that generally saves are called for by other rules, whereas checks are typically at a DMs option. I would add that as such, checks are part of how a DM describes the environment, by distinguishing between what you can do automatically, and what has a chance of failure and thus needs to be rolled.

However, at least from my perspective, Szega gets tripped up by the word "action" in the description of checks, mistakenly assumes it means Action, and goes on to conclude that checks are called for when you have spent an Action on something. I don't think that is true, as a look at other checks will quickly demonstrate. "Walking across a tightrope", for example, calls for a Dexterity check, even though this is done as part of a character's Movement, with no Action having been spent. I think the quote about 'what checks are for' means "actions" in the standard English sense of the word - when a character is simply attempting to do something. So I would say:

Checks are for when a character is attempting to achieve something desired, of their own election. Success on a check means they get what they want, failure means they do not achieve it.

Saves are for when external conditions might impose a negative effect on a character. They are forced to make the save, and the cost of failure is the full imposition of the negative consequence.1 Success on the save is the avoidance, or partial avoidance, of the negative effect.

From this perspective, looking down the list of Con check examples, I would explain them as follows:

Holding Your Breath
If a character goes under water and elects to hold their breath, they can make a Con check - they are trying to achieve something positive. (Note, however, that the rules on Suffocating impose a limit on this - 1 + your Con mod in minutes. You can't just keep making Con checks and hold your breath indefinitely). If, however, the character is in the area of a stinking cloud spell, they are forced to make a Con save to hold their breath. They did not elect this, but they are forced to save in order to avoid something negative (in this case, losing their action to retching and reeling).

Marching or laboring for hours without rest
Suppose a character has already moved for eight hours in a day. They would like to keep marching - that is their desired goal. The DM might call for a Con check for them to exercise that election. If they fail, they might be told, 'no, you are just too tired to continue' with that as the only consequence of failure - they don't get what they want. If they succeed at the check and continue to march for more than an hour longer, though, then they are forced to make a Con save under the rules for a forced march. Now they are required to make a save to avoid the consequence of a level of exhaustion.

Going without sleep
Suppose an adventurer has already been up for a full day of fighting and marching. Their party camps and they take first watch. The DM informs them that they are feeling sleepy and will have difficulty completing their watch. They elect to attempt to stay awake anyway, and the DM calls for a Con check, with failure indicating that they accidentally fall asleep at some point. If the same character has been up for more than 24 hours, though, the DM might impose a Con save to avoid a level of exhaustion (as an optional rule in XGtE suggests).

Going without food and water
If a character is in a survival situation, and trying to ration their remaining supplies of food and water, they might attempt to resist the urge to eat or drink. In this case the DM might call for a Con check - success means they get what they want, and are able to hold out for longer without having to eat or drink supplies that they have. But like Suffocation, regardless of how much they resist the urge to eat or drink, the Starvation rules say that a character who goes without food for more than (3 + their Con mod in days) will take a level of exhaustion, and a character who does not get enough to drink is forced to make a Con save or be exhausted from Dehydration.

Quaffing ale
A character who tries to drink an entire stein of ale without stopping would need a Con check. Failure means they need to pause and take a breath before continuing to swallow, and in this sense it is much like making a check for attempting to hold their breath. There is no complementary save, though, because their really is no appropriate penalty when the environment forces you to try to drink something too fast. Drinking too much might call for a Con save against poison, but generally drinking too fast is simply not a danger most adventurers face.

Why aren't Con checks more common?

As I reflect on my own game, I would almost never call for any of the Con checks that I have described here. I believe that is their proper use according to the PHB, but I would not use them. So why not? Because in almost all of these cases, they fall under something we might call 'willpower', and at least in 5e willpower greatly overlaps with player autonomy. If the typical 5e player was told, "You feel too tired to march" and they responded, "I push through it and march anyway" they would expect to have their character do what they said. They would accept the consequences of exhaustion later, but would bristle at being told they couldn't choose to keep going before they reached the point of exhaustion. If they were told that, "You know you need to save your water but you can't resist the urge to drink more anyway" most of them would feel that that the DM was robbing them of agency. In general, the standard 5e genre assumes that players are in complete, rational control of their characters and can choose to ignore things like mundane tiredness, thirst, or fear. Telling a player they failed a Wisdom save and must run away from a magical fear effect is fine. Telling them they failed an Intimidation check and they are not permitted to tell off the guard is problematic.

This response is notably in contrast to other checks based on Str or Dex. I can't see many players objecting when told they were simply not strong enough to jump across a ravine or not dexterous enough to maintain their balance on ice based on failed checks. But tell them that a failed constitution check means they simply refuse to go outside because it is too cold and you will be accused of running their character for them. This response is also in contrast to other genres or systems, which have rules for piety, temptation, horror, corruption, and so forth. There it is understood that a player is not always in control of their character's decisions.

So, while I do believe that what I have described are the as-intended circumstances for constitution checks, I would be careful when applying them to your game. Certainly a "this is how I intend to use Con checks" disclaimer up front is advised.

1 The clear exception to this are the Chase rules, which require a Con check, not a Con save, to avoid Exhaustion. However, I would argue that Chase exhaustion is not "really" Condition exhaustion, and as such is more a measure of whether you are willing to continue running when you are winded as opposed to something that can actually kill you by imposing conditions on fails. As such, a check is indeed appropriate - but perhaps would be better applied at the start of your turn or when you next attempt to Dash, rather than at the end of your turn.

  • \$\begingroup\$ Perhaps trivially, the saving throw in stinking cloud isn't to hold your breath, it's against poison. \$\endgroup\$
    – Jack
    Commented Jan 10 at 19:32
  • 1
    \$\begingroup\$ @Jack I specifically chose stinking cloud as an example because success on the save results in no ill effect (unlike, eg, cloudkill) and because "Creatures that don't need to breathe or are immune to poison automatically succeed on this saving throw." That to me says if you can hold your breath you don't inhale the gas and are thus unaffected, so the save is not against the poison as much as whether or not you can hold your breath and thus not inhale the poison. \$\endgroup\$
    – Kirt
    Commented Jan 10 at 19:47
  • \$\begingroup\$ Hmm, I see your point! \$\endgroup\$
    – Jack
    Commented Jan 10 at 19:54
  • \$\begingroup\$ I don't see how holding your breath in water vs poison gas is different. Both are environmental hazards that make breathing normally an unwise choice. Are you drawing a line at being prepared to hold your breath? Both could be sudden or something you can prepare for. \$\endgroup\$
    – Szega
    Commented Jan 12 at 23:04
  • \$\begingroup\$ @Szega Water vs. poison gas is not the difference between a check and a save, but rather attempting something vs. being forced to avoid something. If I dive into water and attempt to hold my breath on my turn as part of my movement - that's a check. If a merfolk pulls me under against my will on his turn - that's a save. If a room is full of 'natural' poison gas and I elect to run through it while holding my breath, that's a check. If I am in a stinking cloud, that's a save, because the 'magic' poison gas forces my save regardless of my intent. \$\endgroup\$
    – Kirt
    Commented Jan 13 at 0:31

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