Illusion + Cover

[nickl_2000]

Does an illusion provide cover? As in, I cast minor illusion to make a crate in combat and hide behind it when not popping out to fire an arrow. Does it provide cover?

At what point does it become transparent? When someone fires an arrow through it and it doesn't stick into the crate? Do they need an action to investigate it?

Is this all completely up to the DM's interpretation?

[Ninja_Prawn]

A lot of this will depend on DM's call, but I think the conventional interpretation is that you can Hide behind an illusion, and witnessing something that obviously disproves the reality of an illusion automatically enables people to disbelieve it without a check.

If you created an illusion of half or three-quarter cover, I personally would not allow that to add to your AC. Illusory cover would only be useful if it was full cover that could break line of sight. What you might call 'visual cover'.

[Icewind]

So, it’s definitely up to interpretation, but I would rule that illusions can obscure you but cannot grant you cover, as for it to grant you cover it would have to physically stop anything that would come into contact with it.

If you make an illusion of a box and hide inside it, a creature can’t see your exact position, and thus you’d be heavily obscured. However, its attacks can still pass through the illusory box, so it wouldn’t be able to protect you.

[Composer99]

There's nothing physically there to block attacks, so I would say, no, the illusion doesn't grant cover. That stated, someone fooled by the illusion would not know that. (For instance, if a PC is attacking someone behind an illusory obstacle, they would be told the target has cover, up until the attack swings or shoots through the cover.

I concur with others that an illusion meant to block line of sight does so for any creature fooled by it.

[x3n0n]

Does an illusion provide cover? As in, I cast minor illusion to make a crate in combat and hide behind it when not popping out to fire an arrow. Does it provide cover?

At what point does it become transparent? When someone fires an arrow through it and it doesn't stick into the crate? Do they need an action to investigate it?

Is this all completely up to the DM's interpretation?

Half time DM/player opinion:

Until it is revealed as illusion, as long as you are totally behind it, you are not visible/heavily-obscured, so you can't be targeted by anything that says "that you can see": you seem to be in "total cover". Unless an enemy has some reason to believe it might be an illusion, it is unlikely to even attempt the attack because it knows how cover works.

If you are partially visible, the illusion provides neither half nor 3/4 cover in the event of an incoming attack. (But it may still serve as deterrence from making the attack, as above.)

As normal, as long as you are totally not visible, any incoming attack rolls are at disadvantage. (Since you can see them through it and they can't see you, an outgoing attack would be at advantage).

In general, the first attack through it (in either direction) reveals it to be an illusion. If so, no additional action required. Area effects may reveal it, depending on how the effect "should" interact with it.

[heavyfuel]

Here's how I do it, because it's a way that makes sense to me:

Enemies fooled by your illusion will try to avoid shooting at the cover, but since there's nothing actually stopping the attack, you only gain half the cover benefit to AC (rounded down, and no benefit to Dex saves). If you're in total cover, fooled enemies will try to gain line of sight before attacking.

However, if an enemy would miss due to cover, but in fact hits you because he cover is illusory, this counts as the physical interaction usually needed to notice the created object is an illusion.

For example: If you have AC 16 and create something that gives you 3/4 cover (+5 AC), then your AC becomes 18 (+2). But if the enemy rolls a 19, 20, or 21 to hit, they notice that their attack went through the illusory cover.

Any enemy that somehow notices it's an illusion, will likely tell their team-mates to ignore whatever it is you've "created".

[Segev]

The one illusion spell I can think of that might provide cover is mirage arcane, since it says:
The Illusion includes audible, visual, tactile, and olfactory elements, so it can turn clear ground into Difficult Terrain (or vice versa) or otherwise impede Movement through the area. Any piece of the illusory terrain (such as a rock or stick) that is removed from the spell's area disappears immediately.

Not only are there tactile elements, but they can make terrain difficult or smooth it out, and you can pick them up and try to remove them from the AoE (at which point they disappear). This means they're solid enough to interact with, so I could see an illusory tree produced by this spell, for instance, stopping an arrow.

[Man_Over_Game]

Cover is a physical obstruction. What we're talking about is visibility.

So you can make someone be considered Heavily Obscured/Blinded from attacking you through an Illusion that they don't recognize, but the Illusion doesn't provide any Cover as it's not a physical object.

That's why Wall of Force gives you Cover despite being transparent, while Fog Cloud makes you Blind despite being incorporeal.


Put another way, how would something that wasn't very solid give you a bonus to your Dexterity Saves against an explosion? "Cover" means "Can block a hit".

[heavyfuel]

Cover is a physical obstruction. What we're talking about is visibility.

While this does make sense, it also makes sense that enemies will avoid shooting at 5ft block of stone they think you just created.

[Blood of Gaea]

It makes people think you have cover. You wouldn't just shoot through a brick wall. But if a fireball happens to land around there, it provides no protection.

[Man_Over_Game]

It makes people think you have cover. You wouldn't just shoot through a brick wall. But if a fireball happens to land around there, it provides no protection.

Real cover wouldn't help against Fireball either (but that's because of Fireball, not Cover).

But to address what you're really saying....maybe?

You have to ask yourself, exactly what happens when someone tries to shoot you and it goes through the illusion. They're still aiming at a point near you.


Take a look at the "Hitting Cover" variant rule. If the attack misses the intended target, but would have if they didn't have Cover, they instead attack the Cover. But in this case, we're talking about an Illusion. And without that +2 or +4 AC bonus, you'd be hitting the target anyway.

So, to me, that'd mean the RAW (at least from using variant rules, which includes using a grid or feats) implies that any time you'd miss someone due to Cover is a moment when that Cover would have blocked an otherwise successful shot. Which doesn't work if we're talking about an Illusion.

This is also supported by the fact that being blind imposes Disadvantage on the shooter, while Cover applies an AC bonus to the defender. Having Cover does not make it harder to aim, it just makes the defender harder to hit.

So the options, to me, seem to be:
The shooter believes the Cover is real and changes his strategy around it, but makes his attack as normal.
The shooter believes the Cover is real, and gets Disadvantage for shooting at a target blind (as they cannot see through the illusion).

[x3n0n]

Real cover wouldn't help against Fireball either (but that's because of Fireball, not Cover).

But to address what you're really saying....maybe?

You have to ask yourself, exactly what happens when someone tries to shoot you and it goes through the illusion. They're still aiming at a point near you.


Take a look at the "Hitting Cover" variant rule. If the attack misses the intended target, but would have if they didn't have Cover, they instead attack the Cover. But in this case, we're talking about an Illusion. And without that +2 or +4 AC bonus, you'd be hitting the target anyway.

So, to me, that'd mean the RAW (at least from using variant rules, which includes using a grid or feats) implies that any time you'd miss someone due to Cover is a moment when that Cover would have blocked an otherwise successful shot. Which doesn't work if we're talking about an Illusion.

This is also supported by the fact that being blind imposes Disadvantage on the shooter, while Cover applies an AC bonus to the defender. Having Cover does not make it harder to aim, it just makes the defender harder to hit.

So the options, to me, seem to be:
The shooter believes the Cover is real and changes his strategy around it, but makes his attack as normal.
The shooter believes the Cover is real, and gets Disadvantage for shooting at a target blind (as they cannot see through that Cover).

Yes, what you said.

If they believe you're under cover, they are less likely to shoot.

If you're under illusionary "total cover", you can't be targeted by spells that say "a <target> you can see", and any attacks on you are made at disadvantage.

If you are under illusionary "half-cover" or "3/4-cover", they can shoot as normal and you do not get the AC benefit. To be cute, you could use something like the "Hitting Cover" variant rule to determine whether the illusion is revealed. For example, if it hits but would not have hit if the cover were real, then it hits you *and* reveals the illusion.

[LibraryOgre]

Huh. They got rid of "concealment" in this edition.

I would probably give you half the value of cover as an AC bonus.... so +1, +2, and hidden for 1/2, 3/4, and Full. While you are not actually protected by your illusory cover, it is more difficult to target you, since parts of you are concealed. It wouldn't apply to reflex saves, just physical attacks.

[Segev]

Huh. They got rid of "concealment" in this edition.

I would probably give you half the value of cover as an AC bonus.... so +1, +2, and hidden for 1/2, 3/4, and Full. While you are not actually protected by your illusory cover, it is more difficult to target you, since parts of you are concealed. It wouldn't apply to reflex saves, just physical attacks.

I'd be disinclined to give a bonus to AC for illusory partial cover. The tools we have are Disadvantage (which is reserved for not being able to see the target at all) and AC bonuses (which cover is one of the very few things that gives those), and cover gives them because it actually blocks hits. I think 5e is intending that if you can see the target, it doesn't matter if they're partially obscured, as long as they don't have something narrowing their viable profile, they're valid targets for a normal attack.

I don't know why you'd set yourself up with less than total cover from an illusion, either.

[firelistener]

For me, I wouldn't bother with any mechanical bonus. I don't like rewarding this type of thing as DM because it leads to people trying to cheese fights by fishing for every bonus they can.

Instead, I would just role play any enemies fooled by the illusion that they would try to reposition too see you around the cover clearly or move forward for melee range. When they actually attacked, there would be no AC bonus or disadvantage. That way, it's not totally useless since enemies will change up their tactics, but it doesn't result in cheesy low-level spellcasting for a combat bonus.

[LibraryOgre]

I'd be disinclined to give a bonus to AC for illusory partial cover. The tools we have are Disadvantage (which is reserved for not being able to see the target at all) and AC bonuses (which cover is one of the very few things that gives those), and cover gives them because it actually blocks hits. I think 5e is intending that if you can see the target, it doesn't matter if they're partially obscured, as long as they don't have something narrowing their viable profile, they're valid targets for a normal attack.

I don't know why you'd set yourself up with less than total cover from an illusion, either.

As the OP said, he was looking for total cover he could stick his head out of to shoot people. So, he's covered completely except for "Move to stand, Standard to Shoot, free to drop"... but people still might send missiles his way.

[x3n0n]

I'd be disinclined to give a bonus to AC for illusory partial cover. The tools we have are Disadvantage (which is reserved for not being able to see the target at all) and AC bonuses (which cover is one of the very few things that gives those), and cover gives them because it actually blocks hits. I think 5e is intending that if you can see the target, it doesn't matter if they're partially obscured, as long as they don't have something narrowing their viable profile, they're valid targets for a normal attack.

I don't know why you'd set yourself up with less than total cover from an illusion, either.

Agreed on the intent described in the first part, and it's how I'd rule it at all of my current tables, with rules-lite players. (Mark's variant makes sense, perhaps in combination with the "hitting cover" variant described above, but that seems a lot of rules machinery for something of an edge case.)

On the second, I mostly agree. However, enemy movement is a thing, and they can potentially maneuver into seeing part but not all of you.

[nickl_2000]

For me, I wouldn't bother with any mechanical bonus. I don't like rewarding this type of thing as DM because it leads to people trying to cheese fights by fishing for every bonus they can.

Instead, I would just role play any enemies fooled by the illusion that they would try to reposition too see you around the cover clearly or move forward for melee range. When they actually attacked, there would be no AC bonus or disadvantage. That way, it's not totally useless since enemies will change up their tactics, but it doesn't result in cheesy low-level spellcasting for a combat bonus.

I would have absolutely no problem with this method. By doing this, I can plan in combat and use an illusion to create battlefield control.

[Segev]

Agreed on the intent described in the first part, and it's how I'd rule it at all of my current tables, with rules-lite players. (Mark's variant makes sense, perhaps in combination with the "hitting cover" variant described above, but that seems a lot of rules machinery for something of an edge case.)

On the second, I mostly agree. However, enemy movement is a thing, and they can potentially maneuver into seeing part but not all of you.

I like what I saw somebody suggest about having enemies prioritize targets not in cover if there isn't a reason to target that guy specifically. And, of course, don't tell players when cover is illusory unless they should know it is.

[Hellpyre]

As a DM, I give the benefit of being heavily obscured behind a believed illusion of total cover and lightly obscured behind partial cover. It can't provide an AC bonus if a savvy opponent decides to attack (perhaps because they saw the cover spring into existence and guessed illusion magic might be in play) because it isn't solid. If the cover appears totally natural, and was there before a fight broke out, it would be substantially less likely that an enemy would fire at what looks like an object that would block attacks.

Also, as Segev brought up, if the illusion actually has a physical component, it should provide actual cover as any other physical barrier would.

[Blood of Gaea]

Real cover wouldn't help against Fireball either (but that's because of Fireball, not Cover).


Yes, but only if the Fireball is big enough to wrap around said cover.

[Tanarii]

Does an illusion provide cover? As in, I cast minor illusion to make a crate in combat and hide behind it when not popping out to fire an arrow. Does it provide cover?No. Heavy Obscurement. Or possibly light.


At what point does it become transparent? When someone fires an arrow through it and it doesn't stick into the crate? Do they need an action to investigate it?
When you take an action to disbelieve it and succeed on an Intelligence (Investigation) check

Possibly depending on interpretation, when physical interaction occurs. Further interpretation needed on if it's for the creature physically interacting, for any creature that sees the physical interaction, or for everyone once any physical interaction occurs.


Is this all completely up to the DM's interpretation?
Whether or not physical interaction makes it go faint, and how exactly that works, is DM's interpretation.

Personally I go with physical interaction does not make it go faint. Only a check.

[DwarfFighter]

You should treat the insubstantial cover provided by an illusory crate the same way you would treat a bush or curtain - these types of cover make the target harder to see but their ability to block and attack can typically be discounted.

-DF

[Segev]

Whether or not physical interaction makes it go faint, and how exactly that works, is DM's interpretation.

Personally I go with physical interaction does not make it go faint. Only a check.

I waffle on this a bit. Currently, I lean towards physical interaction revealing it if it can't be otherwise explained. If there's a question as to how convincing the "explanation" would be, I try to do a secret Investigation check, basically letting it be a freebie for those who haven't even thought of it maybe being an illusion, if they're interacting with it in a way that might reveal it.

This tends to mean that soft "cover" / concealment will not be revealed unless somebody explicitly does the Investigation check as an action.

[LibraryOgre]

I waffle on this a bit. Currently, I lean towards physical interaction revealing it if it can't be otherwise explained. If there's a question as to how convincing the "explanation" would be, I try to do a secret Investigation check, basically letting it be a freebie for those who haven't even thought of it maybe being an illusion, if they're interacting with it in a way that might reveal it.

This tends to mean that soft "cover" / concealment will not be revealed unless somebody explicitly does the Investigation check as an action.

Make the box empty, lying on its side, and with the opening facing the opponents. Any arrows that go "through" it just went in the mouth and you can't see them, but they're inside the box.

[Segev]

Make the box empty, lying on its side, and with the opening facing the opponents. Any arrows that go "through" it just went in the mouth and you can't see them, but they're inside the box.

I might allow the auto-Investigation for that, especially since they might hit the top or sides visibly. But yes, that's the right idea for potentially avoiding it. Fog is my go-to example for when I wouldn't allow it without somebody making an action for it.

[Blood of Gaea]

I often lean towards making it look like I cast some sort of spell to manipulate my souronding. In a forest it might be a densle leaf shrubbery, with it's "solid" trunt mostly covered by leaves. Enemies will think it is solid cover, but it can also be harder to spot what happened to your arrow when it flies into the leaves.

On a beach it might just look like I raised a wall of sand, from a distance it's not unlikely to miss the normal puff of sand from your arrow disapearing into the wall, especially in the heat of battle.

Usually how my table does that sort of interaction, is that the person who made the attack can make the check for free, but no one else will notice unless their character was paying specific attention to the formation, in which case they can also get a check.

[Tanarii]

I waffle on this a bit. Currently, I lean towards physical interaction revealing it if it can't be otherwise explained. If there's a question as to how convincing the "explanation" would be, I try to do a secret Investigation check, basically letting it be a freebie for those who haven't even thought of it maybe being an illusion, if they're interacting with it in a way that might reveal it.

This tends to mean that soft "cover" / concealment will not be revealed unless somebody explicitly does the Investigation check as an action.
I should be clear, physical interaction always reveals it to be an illusion. Says so. It doesn't necessarily discern it as an illusion and make it go faint.

The difference is knowing, and successfully convincing your mind over magic to see through it via an action and successful Intelligence (Investigation) check.

Edit: This makes adjudicating Illusions much easier as a DM, less abusable on the edge cases, and more useful in the basic cases.

[Segev]

I should be clear, physical interaction always reveals it to be an illusion. Says so. It doesn't necessarily discern it as an illusion and make it go faint.

The difference is knowing, and successfully convincing your mind over magic to see through it via an action and successful Intelligence (Investigation) check.

Edit: This makes adjudicating Illusions much easier as a DM, less abusable on the edge cases, and more useful in the basic cases.

We differ a little on the interpretation, and probably how we'd adjudicate some edge cases, but I think our approaches actually result in practically-similar rulings under most circumstances.

[Tanarii]

We differ a little on the interpretation, and probably how we'd adjudicate some edge cases, but I think our approaches actually result in practically-similar rulings under most circumstances.
The primary edge cases I referent to worry about is what happens if a caster casts the illusion on top of themselves (entirely encased in it), or in front of themselves and pokes it with a finger.

If that doesn't make it go faint, they can act knowing it's an illusion but don't see through it. I don't have to worry about ruling if it just went faint for them (quite powerful) or everyone (rather underpowered).

[Segev]

The primary edge cases I referent to worry about is what happens if a caster casts the illusion on top of themselves (entirely encased in it), or in front of themselves and pokes it with a finger.

If that doesn't make it go faint, they can act knowing it's an illusion but don't see through it. I don't have to worry about ruling if it just went faint for them (quite powerful) or everyone (rather underpowered).

I tend to go with the quite powerful version, as it makes the most sense to me. They know full well what it is they just created.