D&D 5E Sleep Deprivation Rules?

[Xeviat]

When running my first long term campaign in 5th Edition D&D, I ran into something that the rules just didn't seem to cover. The group was running all night from a monster (specifically a gibbering mouther that had its CR increased). Because the mouther was so slow, they simply chose to flee, and keep fleeing, heading to their next destination. I started looking for rules on how long they could stay awake without involuntarily falling asleep, but I couldn't find anything. I thought it would make for a tense moment.

Now, after digging, I still have found no rules in all of 5E. 3E didn't seem to have them either, at least not in the core books. Is the only requirement for sleep that you cannot recover your HP, HD, and Spells, or that you need long rests to recover fatigue? What if that's not good enough for me?

Looking at the effects of fatigue, I feel it would be safe to say a character suffers a level of fatigue for every 24 hours they go without sleep. Maybe Constitution saves could exist to resist this, or Constitution checks to temporarily power through. World Record sleeplessness for normal people seems to be 8 to 11 days, but they weren't performing strenuous tasks; here are sleepless diseases that can let someone go months of no sleep before death, but again, they're not functioning at any degree.

How would you handle a party trying to march on without sleep?

I did just find the "forced march" rules, which requires a DC 10+1 for every hour past 8 that characters travel. But what if they were just trying to stay awake? Personally, I've gone over 48 hours without sleep, but I was a mess and eventually fell asleep in the middle of what I was doing.

 

[Jester David]

I'd treat it more like food/drink. If the characters fail to get 8 hours of sleep every 24-hours they gain a level of exhaustion.

 

[michaeljpatrick]

I think one level of fatigue for every 24 hours is a good way to go.

Just make sure they know that on the 6th day they will die.

 

[MG.0]

I think it is implied that you would gain a level of exhaustion if you don't get the needed sleep each day. But I think that only makes sense if they still get a couple hours sleep here and there.

If they get zero sleep it should progress faster...in reality you'd be dead before the sixth day rolled around, and useless in half that. Perhaps a level of exhaustion after the first 24 hours, and another after every 12 in which they get zero sleep. Napping for an hour or more will still cause you gain one exhaustion level per day. I like that better.

Also, staying awake is only easy if you are physically active. Any sedentary activity like keeping watch is going to become progressively harder to not fall asleep. Perhaps a constitution check to stay awake. Grant disadvantage after the player has at least two levels of exhaustion.

 

[dpadams0]

Check out AD&D 'Wilderness Survival Guide' by Kim Mohan. Has some good rules about sleep which are fairly edition neutral

 

[steeldragons]

I'm fairly sure this is hy the Exhaustion condition [PHB p.291] mechanic was created. Every 24 hours of activity without sleep should accrue a level of exhaustion. If they spent 24 hours in strenuous activity, like forced march or running for their lives, I'd probably be inclined to slap on two levels off the bat.

 

[Jester David]

I think one level of fatigue for every 24 hours is a good way to go.

Just make sure they know that on the 6th day they will die.

Which isn't that far from reality. Just three days without sleep (72 hours) cripples most people. I believe the record is 11 days. But you're more likely to accidentally fall asleep, so increasingly high Constitution checks to avoid passing out during short rests or quiet periods would be required.

 

[Wik]

Yeah, one of the strengths of 5e is that there ISN'T a rule for everything. You're on the right mark - you're trying to figure out how to respond to this perceived "gap". That's the way it should be handled... and your initial guess seems a fair way to go.

Personally, I'd have the PCs make a con save (DC 10 + current level of exhaustion). Fail it, and they gain two levels of exhaustion. Pass it, and they gain one level. They get disadvantage if they haven't eaten in the last 24 hours, and automatically fail if they haven't had any water.

 

[Xeviat]

I don't have access to any AD&D books, so I'll have to go off of suggestions here.

And yes, the record is 11 days, barring weird medical problems.

I'm now thinking that the Forced March rules might be most of what I really need. Travel and combat would count as exertion, and would call for another check; I'd say an hour of walking would be pretty equivalent to the stress of meaningful combat. The only time anything else would be called for would be if the party was trying to stay up through the night while sedentary. For that, a simple rule could apply.

Sleep Deprivation: Most characters need to sleep for at least 6 hours every 24 hours. Once a character has been awake for 18 hours, they must make a Constitution save. The DC is 10 + 1 for each 6 hours past 18 (10 at 18, 11 at 24). On a failed saving throw, a character suffers one level of exhaustion; if the save fails by 10 or more, they fall asleep. While fatigued in this manner, any strenuous activity (an hour of travel at slow speed, a minute of combat or dashing) counts as a forced march and requires its own Constitution saving throws.

How's that look?

 

[steeldragons]

What AD&D books? It's in the 5e PHB. You're asking/talking about 5e, right?