# How does the Earthquake spell interact with total cover?

The rules on "Area of Effect" state (emphasis mine):

[...] 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.

So for most spells, if somebody is on the other side of a wall they cannot be target by an area of effect spell whose point of origin is on the directly opposite side of the wall. I'm unsure if this is the case with the earthquake spell in particular which states:

[...] For the duration, an intense tremor rips through the ground in a 100-foot-radius circle centered on that point [...]

[...] each creature on the ground in the area must make a Dexterity saving throw. [...]

[...] The tremor deals 50 bludgeoning damage to any structure in contact with the ground in the area [...]

This spell makes an area of effect centered on a point but is a bit unusual in that it can target structures as well as creatures.
There are also area of effect spells like fireball and darkness which explicitly state that they can go around corners, but the earthquake spell does not state this same thing. And so I'm left unsure:

Can earthquake affect something on the directly opposite side of a wall from its point of origin?

• – Medix2 Jun 9 at 23:23

This Reddit post links to a podcast episode with Jeremy Crawford. Among the content, which the comments point out, is this:

Area Spells: like fireball, target not creatures or objects, but a point in space, then expand to include creatures which the spells then refers to 'targets' (here it is "something to be affected" even though before it was used as "something chosen to be affected") because choice is not necessarily a factor, i.e. you can hit a creature with spells like this without intending to.

Many area spells, if targeting the right point, can hit creatures that do not have Line of Sight to you, i.e., that are in total cover (emphasis mine)

"A target with total cover can't be targeted directly by an attack or a spell, although some spells can reach such a target by including it in an area of effect. A target has total cover if it is completely concealed by an obstacle." (Note: an obstacle need not be opaque. Wall of Force blocks targeting on the other side.)

Let's consider a situation where your foes are hiding behind a massive stone wall. You can obviously target Earthquake on a point directly in front of the wall that you can see. The "ground in a 100-foot- radius circle centered on that point" includes ground/area behind the stone wall, and as such, both the wall and creatures behind would be targeted, even though they have total cover.

Another example: Fireball, states "The fire spreads around corners (plural!)." This wording, to me, implies, that explosion would go over the whole wall, as far as filling the 20ft radius goes.

          _
/ \
P_____T/   \E___


If we consider this diagram with the player P, the target point for an AoE spell T, and the enemy E, I would argue that Earthquake hits the enemy through the ground, while Fireball does so over the wall (ranges such that the distance would be covered by the spells radius).

• Spells like darkness and fireball can go around corners/walls/cover because they state so explicitly. The earthquake spell does not state anything similar (that I'm aware of) so why can it do something similar to fireball and darkness? – Medix2 Jun 10 at 0:02
• This is not explicitly RAW but RAI now, of course, but it would seem strange to me that an 8th level spell would not have this as an intended effect when 3rd and 2nd level spells do. Additionally, you're not affecting something in the air/space behind the wall that is off the ground and in total cover, but the ground itself. So, flying or hovering creatures behind the wall would not be affected, for example. – John W. Jun 10 at 0:07
• @Medix2 Because it's being conducted through the ground. The spell says "For the duration, an intense tremor rips through the ground in a 100-foot-radius circle... " – Mark Wells Jun 10 at 0:12
• @MarkWells I guess the answers to this question are wrong, in particular: " The spell's radius would extend in all directions from its point of origin, but it would stop at the wall. The ground behind the wall would be unaffected." though if they are wrong, I'm alright with that – Medix2 Jun 10 at 0:18
• It does seem strange. Keep in mind though that Spike Growth is only a 2nd level spell, much less powerful than Earthquake. From a narrative perspective, this could be described as thorns growing on the surface from the center target point, and stopping at the wall. – John W. Jun 10 at 0:25