Spells during Short Rest

[Raymith]

I was playing in a session today when I had the idea of casting Spider Climb as a Warlock. My question is rather simple. Would concentrating on the Spider Climb spell for the hour that it lasts prevent me from taking a Short Rest while it is active?

Edit: Also, if there is a reference for this, could someone provide it?

[Fordian]

Not generally, no. Per one of the designers (Mike Mearls), you can maintain concentration throughout rests so long as you don't sleep (as he tweeted in response to a similar question on September 19, 2014). It's possible you could have a DM who thinks that concentrating on a spell is strenuous enough as to prevent short resting, but as normal activity (conversing, reading, running, even non-damaging combat) isn't enough to break concentration (per the PHB rules on concentration), most wouldn't rule that it's mentally taxing enough to prevent short rests. It may not be explicitly stated in the rules that that's the case, but it's certainly the designers' intention. Note that this is particularly useful for a Warlock, as a higher-level Hex spell lasts well over an hour, enabling you to cast it early in the day, maintain concentration during subsequent short rests - so long as you don't lose concentration in combat or cast other concentration-requiring spells - and enter later combats with Hex already active and all spell slots available for use.

Now, in the specific case of Spider Climb, with a duration of only 1 hour, I don't really see what benefit you could gain from having it active during a short rest... if you cast it before the short rest, it'll end before the short rest ends. Unless your plan is to cast it right before starting a short rest and spend all but the last few seconds of the short rest on a wall or ceiling? Probably allowable, but check with your DM (technically, the spell would end a few seconds before the rest, so if it's too hard even with Spider Climb to get back to solid ground while not breaking the short rest, such as if you were 250 feet up a 500 foot cliff, you might end up falling or failing to successfully rest - though that's because of the hazardous environment and not because you were concentrating on the spell).

[Trickshaw]

RAW

Unless you are knocked unconscious, fall asleep or fail a concentration check there is nothing preventing you from maintaining concentration on a spell.

That said, your DM has final say. But I would emphatically emphasize to said DM who may disagree that a player can cast another spell (a bunch of other spells), wrestle a bugbear, scale a 200ft wall, pick a lock or any number of complex and strenuous activities without losing concentration. So sitting quietly in a corner reading a book or bandaging your wounds doesn't seem like a far off stretch to me.

[JoeJ]

RAW

Unless you are knocked unconscious, fall asleep or fail a concentration check there is nothing preventing you from maintaining concentration on a spell.

That said, your DM has final say. But I would emphatically emphasize to said DM who may disagree that a player can cast another spell (a bunch of other spells), wrestle a bugbear, scale a 200ft wall, pick a lock or any number of complex and strenuous activities without losing concentration. So sitting quietly in a corner reading a book or bandaging your wounds doesn't seem like a far off stretch to me.

I agree that RAW you can do it. For a DM that says otherwise, however, their view is probably not that you can't maintain concentration while sitting quietly, but that you can't get the benefit of a rest while you're concentrating.

[Aett_Thorn]

I agree that RAW you can do it. For a DM that says otherwise, however, their view is probably not that you can't maintain concentration while sitting quietly, but that you can't get the benefit of a rest while you're concentrating.

Which would absolutely hose Warlocks that use Hex, since it lasts pretty much the whole day and would therefore completely ruin their short-rest recharge spellcasting mechanic.