Does the Eyebite spell work through a Wall of Force? Or is it blocked by Full Cover, even if the target can be seen?
This question is similar to this, but contrarily to Gaze effects the spell Eyebite obeys the following rule regarding spell casting:
To target something, you must have a clear path to it, so it can’t be behind total cover.
In general, 5e rulings are adjudicated first by following exactly what is written, and second (if what is written is unclear or silent on the subject in question) by the GM. So, my answer is:
This GM would rule that yes an eyebite spell could affect through a wall of force (WoF). The WoF spell says that it protects (or, traps) like so (emphasis mine):
Nothing can physically pass through the wall. It is immune to all damage and can't be dispelled by dispel magic. A disintegrate spell destroys the wall instantly, however. The wall also extends into the Ethereal Plane, blocking ethereal travel through the wall.
The eyebite spell reads like so (emphasis my own):
For the spell's duration, your eyes become an inky void imbued with dread power. One creature of your choice within 60 feet of you that you can see must succeed on a Wisdom saving throw or be affected...
Eyebite simply requires that the victim be seen but not interacted with in any other way. Since WoF is a transparent barrier, it can be seen through, thus eyebite works.
With that ruling, this GM might end up on an unraveling, or nerfing, of the WoF spell. This previous discussion explains that a WoF blocks all spells by creating total cover. Simply put, a creature within the WoF cannot be the target of a spell. Ah, you say, but eyebite's target is "self"--too true! The victim of the eyebite spell must then be merely "seen" (not "gazed") and, we wind up back at my ruling above that transparent walls can be seen through and thus, the eyebite spell works through WoF.
So it comes down to this: The GM needs to rule whether or not "seeing" the victim of the eyebite spell counts as targeting for the purposes of cover.
No
spells require a clear path to the target. Any form of total cover prevents that. thus you cant do it
cover states
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.
A creature inside a wall of force has total cover thus it cant be targeted
Its the same reason you cant cast hold person on a person behind a closed window, or why you cant directly target a creature inside a glass dome with firebolt. Whether the creature is visible isnt relevant here
