Part of an ongoing series of 5e Rules notes.
Our Tempest Cleric had the Wrath of the Storm class ability (strictly speaking, not a spell), and endlessly enjoyed using it. Even when she took a bigger smack than her attacker did in turn, she just enjoyed the free combat.
It is, in fact, pretty cool:
Also at 1st level, you can thunderously rebuke attackers. When a creature within 5 feet of you that you can see hits you with an Attack, you can use your Reaction to cause the creature to make a DEXterity Saving Throw. The creature takes 2d8 lightning or thunder damage (your choice) on a failed Saving Throw, and half as much damage on a successful one.
So in one game, a Smoke Mephit did its ash breath on the cleric from from the adjoining square. This isn’t a To-Hit roll Attack, but an AoE Affect. Should it trigger Wrath of the Storm?
The answer seems to be NO. Because the AoE weapon isn’t, strictly speaking, hitting with an Attack. The key here is “hits you with an Attack.” And the PHB (p. 194) is clear what that all means:
When you make an attack, your attack roll determines whether the attack hits or misses. To make an attack roll, roll a d20 and add the appropriate modifiers. If the total of the roll plus modifiers equals or exceeds the target’s Armor Class (AC), the attack hits. The AC of a character is determined at character creation, whereas the AC of a monster is in its stat block.
Attacks are made with a d20 roll against a target’s AC. But that’s not what happens with the Smoke Mephit’s breath, or a Dragon’s breath weapon, etc. Those:
- are not targeted at someone
- don’t require an attack roll
- aren’t defended by AC
Instead, AoE attacks create a condition in a certain area of squares, and if someone is in that area, they automatically have to make a Saving Throw to determine the severity of the conditions that ensue (which may or may not include damage; the smoke mephit’s ashy breath caused blindness).
(This is part and parcel of why an AoE attack from an adjoining square doesn’t trigger any Disadvantage, either — because there’s no attack roll to Disadvantage.)
If there’s no attack roll (and, of course, a hit caused by a successful attack roll), Wrath of the Storm does not trigger. That would include attacks with Magic Missile, Hold Person, or even Wrath of the Storm itself:
A consequence of this is that if two tempest clerics are fighting one another, and Ann smacks Bob with her mace, Bob may use Wrath of the Storm on Ann as a Reaction, but Ann cannot retaliate in turn, even though she might have a Reaction available, because Wrath of the Storm does not qualify as an attack.