Can Hail of Thorns spell stack with Conjure Barrage?

Question

The description of each spell:

Hail of Thorns (concentration): The next time you hit a creature with a ranged weapon attack before the spell ends, this spell creates a rain of thorns that sprouts from your ranged weapon or ammunition. In addition to the normal effect of the attack, the target of the attack and each creature within 5 feet of it must make a Dexterity saving throw. A creature takes 1d10 piercing damage on a failed save, or half as much damage on a successful one.

Conjure Barrage (Instant):You throw a nonmagical weapon or fire a piece of nonmagical ammunition into the air to create a cone of identical weapons that shoot forward and then disappear. Each creature in a 60-foot cone must succeed on a Dexterity saving throw. A creature takes 3d8 damage on a failed save, or half as much damage on a successful one. The damage type is the same as that of the weapon or ammunition used as a component.

What I want to do is cast hail of thorns as a bonus action and then cast conjure barrage. Each creature that I'm firing on must make two dexterity saves — the first save for conjure barrage, the second for hail of thorns.

To me the only way this would work is if conjure barrage is a ranged weapon attack. To me it seems as though it is, because I'm firing a piece of nonmagical ammunition. And hail of thorns doesn't make my ammunition magical, it just causes thorns to explode out from them on a hit. What I picture happening in game is my character shooting an arrow, the arrow flies out and then multiplies as it goes in a cone, and then each arrow in the cone hits a target and then sends thorns going everywhere.

Can the spells stack that way?

Answer 1

Conjure Barrage is not a ranged weapon attack.

This does not work because "ranged weapon attack" in D&D 5e is a term of art--it refers to a specific piece of the rules, and not necessarily the underlying fiction. While the effect of conjure barrage may intuitively seem like a ranged weapon attack, it is not a "ranged weapon attack" as far as the rules are considered.

A "ranged weapon attack" is partially defined on PHB 194:

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.

On the other hand, conjure barrage asks for a saving throw—it is the target that rolls the dice in that situation. Because it calls for a saving throw, and you don't make the attack, it doesn't work.

Compare this situation to a spell like fire bolt, which asks you to make a ranged spell attack. In this case, you're making an attack, so you roll the d20, but it's still not a "ranged weapon attack" because it's a "ranged spell attack".

Essentially, you need to fulfill all three words of the phrase. You must make an attack (you roll the attack roll), at range, using a weapon.

Note that you can't cast those spells in one turn.

The wording in your question is a bit ambiguous, but it's important to note that you can't cast both of those spells in one turn, because that would require a bonus action spell and a 3rd level spell. PHB 202 states, (emphasis added)

A spell cast with a bonus action is especially swift. You must use a bonus action on your turn to cast the spell, provided that you haven’t already taken a bonus action this turn. You can’t cast another spell during the same turn, except for a cantrip with a casting time of 1 action.