D&D 5E Rule question: Temporary HP and concentration checks

[Ancalagon]

Say that you've go 10 temp hp and are maintaining concentration on a spell. Some punk goblin hits you with an arrow for 5 hp damage.

Do you have to make a concentration check? You haven't lost any "real" HP...

 

[Satyrn]

I don't know. I think I'd still require the check . . . Although I have several monsters who constantly regenerate lots of Temp HP, so it would be more evil of me if didn't require the check.

. . . Not that any of those monsters have anything to Concentrate on.

 

[Ristamar]

Yes. Damage to temporary HP is still damage.

 

[Ancalagon]

Yes. Damage to temporary HP is still damage.

Is this an opinion or do you actually know?

 

[Ristamar]

Is this an opinion or do you actually know?

https://www.sageadvice.eu/2014/09/02/temporary-concentration-dc/

 

[jgsugden]

Taking damage. Whenever you take damage while you are concentrating on a spell, you must make a Constitution saving throw to maintain your concentration. The DC equals 10 or half the damage you take, whichever number is higher. If you take damage from multiple sources, such as an arrow and a dragon's breath, you make a separate saving throw for each source of damage.

When you have temporary hit points and take damage, the temporary hit points are lost first, and any leftover damage carries over to your normal hit points. For example, if you have 5 temporary hit points and take 7 damage, you lose the temporary hit points and then take 2 damage.

Concentration checks are performed when you take damage. Temporary hit points have damage removed from them before going after your new hps, but you are still taking the damage.

Plus, we have Sage Confirmation: https://www.sageadvice.eu/2014/09/02/temporary-concentration-dc/

 

[Dausuul]

Say that you've go 10 temp hp and are maintaining concentration on a spell. Some punk goblin hits you with an arrow for 5 hp damage.

Do you have to make a concentration check? You haven't lost any "real" HP...

My instinctive response was "yes, you have to roll," but when I went to look up the rules, I found it was not as clear-cut as I originally thought. Here are the concentration rules:

Whenever you take damage while you are concentrating on a spell, you must make a Constitution saving throw to maintain your concentration. The DC equals 10 or half the damage you take, whichever number is higher. If you take damage from multiple sources, such as an arrow and a dragon's breath, you make a separate saving throw for each source of damage.

And the temporary hit points rules:

When you have temporary hit points and take damage, the temporary hit points are lost first, and any leftover damage carries over to your normal hit points. For example, if you have 5 temporary hit points and take 7 damage, you lose the temporary hit points and then take 2 damage.

Note the phrasing of the final sentence: "If you have 5 temporary hit points and take 7 damage... then take 2 damage." The way this is phrased suggests that the temporary hit points are intervening before the damage actually hits: "Take 7 damage" is replaced with "lose the temporary hit points and take 2 damage." So "take 4 damage" would be replaced with "lose 4 temporary hit points and take no damage," which would mean no Concentration save.

Purely based on the text of the temporary hit point rules, this is the logical reading. However, this has somewhat far-reaching implications. It means that any time a PC with temporary hit points gets hit by something with a rider effect (e.g., poison), you have to consider whether preventing the damage should prevent the rider effect as well.

It also makes temporary hit points far more valuable to spellcasters. Armor of Agathys, for example, would be a must-have spell for bladelocks. That isn't necessarily a bad thing--bladelocks kinda need the help--but it's something to be aware of.

Ultimately, I think I would go with my original response, but that is my personal ruling, based less on the RAW than on a sense of "do not open a can of worms if you don't have to."

(If you put stock in Sage Advice, Jeremy Crawford says you have to make the save. However, he does not justify this with any citations from the rules.)

 

[Oofta]

I'd say you need to make the concentration check, you are still taking damage. The concentration rules don't specify "HP damage"

Concentration: Whenever you take damage ...
Temporary HP: When you have temporary hit points and take damage ...

Damage is damage, some of it reduces your HP total, some does not.

 

[TheSword]

I guess the point is that taking damage even if it doesn’t hurt you is still distracting.

 

[Seramus]

RAW suggests that damage to temporary hit points are not actually damage to you, as clarified by the Temporary Hit Point rules that specify how much damage you actually take at the end of the calculation. However, Sage Advice has suggested the opposite of this. So it may be possible that they intended for THP to count as actual damage to you and they just goofed the RAW.

I've been in groups that played it both ways, and... while the implications are pretty massive, it doesn't slow down play or anything. Actually works in the monsters favor more.