D&D 5E Arcane Eye - Working out the unexplained...

[jgsugden]

I'm curious how DMs handle the Arcane Eye spell's ambiguities. As some high level warlocks can cast it at will, I assume some people have had to deal with a lot of nuanced uses of the spell.

When Arcane Eye is cast, it creates an invisible, magical eye that floats around at your direction and spies on the world. However, there is nothing in the rules that say that this eye is hidden. Only invisible. Hidden and invisible are different in 5E. Invisibility makes creatures so that you can't see them without magical aid, but you can still detect the presence of them unless they are also hidden. Does that rule extend to objects or spell effects?

• If so, as the eye is not hidden, does the enemy know the eye is there, but just can't see it? Does it get to use the wizard's stealth perhaps to stay hidden? Or do all Arcane Eyes get the same default DC to be detected in your games?
  
• If not, is the eye effectively hidden from even the most observant of enemies unless they have magical senses that can see invisible?

Also, does the eye have substance? The spell says it creates an eye (and eyes have substance) but it is magical - so it could go either way. It isn't a conjuration spell - so what is the eye made of? What if the eye accidentally (or intentionally) bumps into something (perhaps an invisible something)? Does the rule that solid barriers block it mean that it stops as soon as it makes contact and exerts no force on the thing it hits? What if something walks into the spot the eye occupies? Can I hang a cloak on an arcane eye? Or will that just force the eye to the ground buried by the cloak?

The eye can't leave the plane it is cast on, but the spell says nothing about me leaving the plane I cast the spell upon - does it continue to work for me if I planeshift away to another plane? The eye has normal and darkvision out to 30 feet - what if something is 35 feet away? Is it completely invisible and hidden from the eye, or does the vision just get blurry after 30 feet?

 

[Phazonfish]

Not sure how correct my answer is but I would rule that objects and such don't have to hide to be hidden (as they don't do things like breath or move), and that you strictly need a sense that can detect them. You would need a magical sense of some sort to find the sensor for Arcane Eye because it's not noted to have any kind of sound or smell that it gives off, but for other objects the sense need not necessarily be magic (for instance, a good sense of smell can find an invisible object that has a noticeable scent).

 

[Croesus]

Arcane Eye
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.

No reference is made to perception rolls or stealth checks, so I would rule that the eye cannot be noticed except via magical means, e.g., see invisibility. That said, I think it would be fine to allow targets a Wisdom (Perception) roll, DC 20, to "feel" like they are being watched.

No hit points or AC is listed for the eye, so I would suggest it is insubstantial. However, the spell specifically mentions that it needs an opening at least 1" in diameter, so it at least has some line of effect issues.

Based on the description above, you cannot see further than 30'. I would describe it as edges blurred to a point that one can make out nothing, not even color, but other fluff works just as well. The key is that vision is limited to 30' in radius from the eye's current position.

As for planes, I would rule that if the caster leaves the original plane where the spell was cast, the spell simply ends. The caster could, of course, re-cast the spell on the new plane.

 

[thethain]

Hidden - I would rule it as hidden as it has no means of making noise. Hidden is intentionally give a LOT of leeway in 5e for DM discretion. If you did want it to be detectable, I think the logical perception DC would be the spell save DC of the caster.

I would rule that it has substance since it needs at least an inch to pass through an area. The eye is made of ether, or whatever material every minor conjurations are made of.
As for its ability to move and bump into things, I'd rule it could bump into things, but it would be an extremely light amount of force, you couldn't use it to even push a glass off a table. If it bumped into a creature, there would be a chance the creature wouldn't even notice.

The eye is NOT a creature, therefore it can occupy the same space as creatures. (You can stand in a square that has a sword on the ground).
The eye is NOT a creature so cannot attune to or use magical items.
The eye is not given a carrying capacity so any weight on it will force it to the ground.

The eye continues to function on a different plane, any spell continues to function unless it specifies a condition for it to end (mage hand for example ends when over 20ft away).
It has normal vision and Darkvision out to 30 ft. I count this as it having normal vision, but also having the property of darkvision (30). The reason is many monsters specify when they are blind beyond a sight. (Animated objects have blindsight 30, blind beyond this range).


Just remember that the eye is not a creature, it is a spell effect. You can treat it like an object if needed. But any properties of it should be assumed to be minimum needed for it to fulfill its function. So it would be fair to assume its a 1 inch diameter sphere, that has just enough force to allow it to fly thru the air.

EDIT: Crawford ruled the normal vision is limited to 30 ft as well, although then ruled a mirror would still still be viewed normally... MAGIC
http://www.sageadvice.eu/2017/01/07/does-arcane-eye-can-only-see-w-normal-vision-up-to-30ft-away/

 

[Ancalagon]

You know, I think that for me the fundamental impact of the spell on story-telling are far more troubling than the minutia of the in-game effects.

It is an *excellent* scout. Why would a wizard ever *not* scout ahead with this spell? Information is power. And logically the rest of the party would want to know what's ahead instead of charging in blind. But it's not as fun a gaming experience to have the GM describe the "adventures of the eye" in most sessions...

 

[MonkeezOnFire]

You know, I think that for me the fundamental impact of the spell on story-telling are far more troubling than the minutia of the in-game effects.

It is an *excellent* scout. Why would a wizard ever *not* scout ahead with this spell? Information is power. And logically the rest of the party would want to know what's ahead instead of charging in blind. But it's not as fun a gaming experience to have the GM describe the "adventures of the eye" in most sessions...

I realize that this mostly comes down to play style differences, but I really disagree that scouting out before hand with arcane eye is very useful. I have it on my 9th level wizard and it's seen some use, but it's not a go to strategy for us. There aren't a lot of monsters in 5e that require special preparation in order to fight them adequately. On the times that we encounter those that do have been foreshadowed through interactions with the environment or interacting with NPCs (example, the medusa lair we entered had a ton of statues around it's entrance). So really we don't gain a lot by finding out if the monsters in the next room are an earth elemental, or a stone giant, or a group of duergar. You could argue that you also get information about the environment but you can get that same information by just exploring with the whole party normally. Monsters move about the dungeon making information about their position unreliable.

4th level slots are also still fairly near the top of my power level. Giving up a 4th level spell means giving up considerable fire power during a combat. Conjure Minor Elementals and Evard's Black Tentacles are great spells that can really turn the tide of a fight.

Arcane Eye does have great uses. Check out areas that are hard to get to, monitor an area while the rest of the party sets up an ambush, scouting two areas at a time without actually splitting the party.

 

[FormerlyHemlock]

You know, I think that for me the fundamental impact of the spell on story-telling are far more troubling than the minutia of the in-game effects.

It is an *excellent* scout. Why would a wizard ever *not* scout ahead with this spell? Information is power. And logically the rest of the party would want to know what's ahead instead of charging in blind. But it's not as fun a gaming experience to have the GM describe the "adventures of the eye" in most sessions...

[I'm a huge advocate of reconnaissance, so take the below as a list of exceptions and not a slam on the utility of Arcane Eye.]

Why would a wizard NOT scout ahead? Because 1"-wide eyeballs don't fit under doors, and cannot open doors.

It becomes markedly more useful if paired with, say, an invisible Imp familiar who can open doors. But then it is also somewhat redundant as well.

Other potential reasons not to scout ahead with Arcane Eye:

(1) Because the Shadow Monk and the Lore Bard have already done so, and the Shadow Monk (unlike the Wizard) has high Wisdom, while the Lore Bard (unlike the Wizard) has Expertise in Stealth and Perception, so both of them are markedly better than the Wizard anyway at noticing things while scouting.

(2) Because your concentration is busy on something else, e.g. keeping the aforementioned Lore Bard Invisible while he scouts.

(3) Because the area you're in is active enough that there is either no time for scouting, or no point in scouting because the situation will have changed by the time you get there. Think here of e.g. a military base with patrols and soldiers moving everywhere. Even if you hole in up a cargo container and send out your little spy-eye, all you're going to get is a bunch of information to the tune of "a patrol just went that way... another patrol is coming this way..." etc.--you won't find a safe path that is free from patrols because the whole point of patrols is to make sure no such path exists. (Or maybe you will find one, over the rooftops, because the Evil Overlord forgot to guard against flying enemies. In this case #3 doesn't apply.)

(4) Because you can't afford the 4th level spell slot.

So, it's a cost-benefit tradeoff. Recon is important, but sometimes you can get the same thing cheaper some other way; or you can't afford it at all.

 

[jgsugden]

Good thoughts. While I've seen this spell get some use by wizards, it is the 15th plus level warlocks that SPAM this spell that spawned my interest in this thread.

 

[Mistwell]

You know, I think that for me the fundamental impact of the spell on story-telling are far more troubling than the minutia of the in-game effects.

It is an *excellent* scout. Why would a wizard ever *not* scout ahead with this spell?

Because they could accomplish most of the same thing with a first level spell? Find Familiar.