Can the Dragon's Breath spell damage enemies with no clear path to the caster?

Question

Can Dragon's Breath spell damage enemies that do not have a clear path to the caster?

The PHB page 204 says:

To target something, you must have a clear path to it, so it can’t be behind total cover.

The Dragon's Breath spell is unique in that the both the touched creature (user of the breath) & the enemies are targets:

Dragon's breath has two sets of targets: the creature you give the breath weapon to and the creatures in the area of effect created by the spell

What if the enemies have total cover from the caster, but not from the user of the breath?

Answer 1

Total cover and areas-of-effect care about the point of origin, not the caster

Dragon's breath goes through two 'steps'; first the spell is cast on a creature which is targeted by a range of touch. The standard rules for targeting with touch applies. Then the affected creature (for as long the spell lasts) can use its action to produce an area-of-effect which deals damage.

The relevant excerpt from the Player's Handbook with regards to areas-of-effect:

A spell's effect expands in straight lines from the point of origin. If no unblocked straight line extends from the point of origin to a location within the area of effect, that location isn't included in the spell's area. To block one of these imaginary lines, an obstruction must provide total cover [...]

--- Player's Handbook, p. 204

Which as dragon's breath has no exceptions to this (some other spells say "this effect spreads around corners" or some-such), the spell's area-of-effect is blocked by corners.

However, the area-of-effect of dragon's breath is a cone originating from the the affected creature (the one that has to use its action). The position of the caster does not come into the picture.

Similarly, a spell with a area of a sphere can affect a creature that has total cover from the caster, as long as the point of origin (in this case the center of the sphere) has a clear line to that creature.

Answer 2

The spell description says that the caster must touch a willing creature to cast the spell. Touch does not actually require "line of sight", it simply requires being with 5 feet and not have any sort of barrier between the caster and the recipient.

Once the spell has been cast, the user is Concentrating on maintaining the spell but is otherwise going about their day and has nothing whatsoever to do with the targeting of the dragon's breath.

It is the recipient of the spell who is using an action to perform the breath attack therefore they are the ones choosing where the Dragon's Breath attacks are directed.

The rule on PHB 204 about being able to see your target is a "general rule" and does not apply in all cases. Dragon's Breath is a cone shaped area of effect originating from the attacker's mouth and extending 15 feet. You do not target enemies with it, you choose a direction which could be specified as "towards that enemy" but could also be "north", "up", "to my right", or "into that corner of the room where I think somebody is hiding." Anybody in the cone shaped area of effect, whether visible to the attacker or not, is subject to the effects of the Dragon's Breath.

Answer 3

The PHB states (p. 204; emphasis mine):

Spells such as burning hands and cone of cold cover an area, allowing them to affect multiple creatures at once. […] A spell's effect expands in straight lines from the point of origin. If no unblocked straight line extends from the point of origin to a location within the area of effect, that location isn't included in the spell's area. To block one of these imaginary lines, an obstruction must provide total cover.

This means, that the effect Dragon's Breath can be blocked by total cover.

Additionally, the target of the spell being cast is only relevant to the willing creature that will be using the AoE effect of the spell.

The Cover rules also state that they will gain a bonus on Dexterity saving throws to avoid such effects (p. 196)

A target with half cover has a +2 bonus to AC and Dexterity saving throws.

A target with full cover has a +5 bonus to AC and Dexterity saving throws.

However, the spell still affects those in the area even if they make a successful save.

Answer 4

Total cover between the enemies & the caster doesn't stop the spell

The confusion arises because the caster and the spell don't have the same targets.

Targets of the Spell: The spell Dragon's Breath does indeed target both the touched creature and the damaged enemies.

The Evidence for RAI is Jeremy Crawford explicitly said so,

Dragon's breath can affect more than one creature with the exhalation

Evidence for RAW is that since "target" isn't a keyword, we therefore use the plain English meaning of "target":

Target: a person, object, or place selected as the aim of an attack.

Exhaling energy toward creatures means the creatures are targets of the breath, and therefore they count as targets of the spell.

We therefore have both RAI & RAW evidence that the spell has multiple targets.

Target of the Caster: However, the caster only targets a single creature: the one who is given the breath.

Similarly, the one using the breath has only the enemies as targets.

This explains why total cover between the caster & the enemies doesn't matter: the caster never targets these enemies in the first place.