Spirit Guardians has a Range of Self (15-foot radius) (and adds in the description that the Spirits "flit around you to a distance of 15 feet for the duration")
Given this situation:
The cleric (in yellow) casts the spell. The door to the room below is open but the cleric does not have line of sight. Does the foe in that room take damage at the start of their turn?
(Note that the topology here makes moot other questions addressed on this stack as to whether the spell is centered on an adjoining intersection or on the caster, or what the shape of the radius is.)
There is no line of sight between the cleric and the foe. If it were a Fireball she were throwing at her feet, the foe would be affected, because the description of Fireball makes mention of going around corners. The language of Spirit Guardians is not nearly so clear. The discussion about Spike Growth here (i.e. "you cannot target a point that is blocked by total cover.") doesn't seem to apply, because Spike Growth is targeted, but the Spirit Guardians are not.
I see three answers:
- Yes, because the Spirits flit within the given radius and, like a Fireball, as long as nothing is totally blocking them, they fill the area.
- Yes, because the foe is within 15 feet moving distance from the cleric, which is how far away the Spirits can go. In this case, the actual area of the spell would not actually being a circle is affected by travel distance from the cleric; the table at the bottom of the image would actually be out of range because of having to go around the corner into the room.
- No, because there's no Line of Sight between the cleric and the foe, and the Spirits don't go around a corner. If she moved left a square of two, she, and the Spirits, would be able to target the foe.