Level
4th
Casting Time
1 Action
Range/Area
30 ft
Components
V, S, M *
Duration
Concentration
1 Hour
School
Divination
Attack/Save
None
Damage/Effect
Detection
You create an invisible, magical eye within range that hovers in the air for the duration.
You mentally receive visual information from the eye, which has normal vision and darkvision out to 30 feet. The eye can look in every direction.
As an action, you can move the eye up to 30 feet in any direction. There is no limit to how far away from you the eye can move, but it can't enter another plane of existence. A solid barrier blocks the eye's movement, but the eye can pass through an opening as small as 1 inch in diameter.
* - (a bit of bat fur)
could the eye read a book really really fast?
Any sentence that begins with "by standard rules" always concerns me. Its a 4th level spell made for detection and stealth. Shouldn't be questioned that hard. Its a resource the player is using and any DM should allow that
You must read the entirety of a spell. Detect Magic first will "sense" the presence of magic in range, regardless of its state of visibility. IF that state has been achieved, and the source is a creature or object that is visible to the caster, THEN the caster may look at its aura and determine the school of magic of its source. A caster who cannot see the Arcane Eye would know something magical was there, and know where it is, but would not see any aura (or anything) when looking there. The same caster with see invisibility, true sight, etc active at that time would see the Arcane Eye, accompanied by a faint visible aura of divination.
For those with such large issues with Arcane Eye, you can try and twist it, but it actually just does exactly what it says. If there is light, it sees normally. If it is dark, it has darkvision to 30 feet. If it is blocked by an obstacle that doesn't have a 1 inch gap to fit through, its stuck. Any DM should be able to balance this spell out as an appropriate use of a Level 4 spell slot with relative ease, and if you want to protect an area from an Arcane Eye, all it takes is a closed, well fitted door without some giant keyhole to squeeze through.