The Art of Illusion - Question

[Voltage89]

Hey everyone. I have a question about how you guys rule seeing through illusions. Let's say in combat I through up an illusion using silent or major image. The image is of a wall or maybe of a barbarian sprinting at the enemies screaming. Now, an archer shoots at the illusion and obviously, the arrow passes through. Would you say that just that enemy now knows it is an illusion, or that the other enemies do as well?

[Voltage89]

Oh, I also was wondering if anyone would make the person actually roll an attack against the illusion. The reason is the attack could miss the illusion, thus the attacker still not knowing whether it is an illusion or not.

[sophontteks]

Anyone who witnessed the arrow pass through would know its an illusion.

[Voltage89]

Anyone who witnessed the arrow pass through would know its an illusion.

That is kinda what I was thinking, but that seems to really make illusionist seem like crap

[Greywander]

Yes, if you touch an illusion, including throwing or shooting something at it, you will see your hand or arrow or whatever pass through it, and you'll know it's an illusion.

If you created an illusion of a wall, I probably wouldn't require an attack roll to hit it. But if you made an illusion of a creature, I probably would (but I'd give it a low AC, maybe 5).

You can also discern an illusion by making an Investigation check, if you're not keen on touching it, but it takes an action to do so. The DC would be the spell save DC of the caster of the illusion.

Also, if you throw down a lot of illusions, enemies might wise up to it and start assuming that effects you create are just illusions. You can use this to your advantage by, say, creating a real wall and then watching them run smack into it. Mix it up every now and then by tossing out a non-illusory spell, and make sure your illusions are varied as well so they can never tell if it's real or fake.


That is kinda what I was thinking, but that seems to really make illusionist seem like crap
Not necessarily. You wasted one enemy's attack, that's not too bad. Maybe not worth a 1st level spell slot in most cases, but it could be a life saver if you're fighting an ancient dragon.

If you're worried about archers, drop a fog cloud on them instead. They'll have to move out of the cloud or suffer disadvantage on their attacks (also, they can't run behind the cloud or else they still won't be able to see through it. They'll have to run sideways or toward you, so maybe you can force them to come into melee range). For melee enemies, create an illusion of something they don't want to touch or attack, like a wall of fire.

You can get a lot more mileage out of illusions by being creative with them instead of relying on a few effects (such as walls). Think of another type of spell or effect you might want to create and see if you could make an illusion that might have a similar effect. For example, create an illusion of a basilisk (pretend you're summoning it or something) and creatures who know what it is will avert their gaze so they don't turn to stone. They may, or may not try to attack it, but whatever they do will be with disadvantage because they can't see what they're aiming at.

EDIT: Since they're averting or closing their eyes, even if they hit the illusory basilisk they might not realize it is an illusion since they can't see it. However, if the basilisk just stands there doing nothing, they'll probably figure out that something is up. Also, not every creature will know or care what a basilisk is.

[Sinon]

Put arrow slits in the wall.

An arrow moves fast enough that you can't say for sure whether or not it passed directly through a narrow gap or not.

Or...

Make it an illusory wall of smoke, or of leaves, or bees - anything that blocks line of sight but could still allow an arrow to pass through.

[Voltage89]

I just really wish there were a few damage illusion spells as thst is what my wizard will be mainly focusing on. Thanks though everyone.

[Greywander]

I just really wish there were a few damage illusion spells as thst is what my wizard will be mainly focusing on. Thanks though everyone.
Nobody becomes an illusionist to be a top tier damage dealer. If that's what you want, you should have become an evoker instead. Illusion is all about control and manipulation, which is in my opinion far more valuable. Leave the damage dealing to the fighter and rogue. And if you really need to get medieval on someone, nothing is stopping you from learning Fireball.

That said, check out Phantasmal Force and Phantasmal Killer. These would be your offensive illusion spells.

[Unoriginal]

That is kinda what I was thinking, but that seems to really make illusionist seem like crap

Ask yourself: why would an archer shoot a wall?

Being an illusionist means you have to think of things people won't try to interact with, if interraction reveal the trick

As long as they're under the spell's effect, the enemies beave as if it was real. So, why would an archer aim at a solid stone wall?

[Aaedimus]

Illusionist can be the strongest archetype if you've got a good imagination.

If you want to play that archetype you need to talk to your DM first, because the viability depends soley on how well he or she keeps with the rules of detecting illusions.

Detecting an illusion without touching it is supposed to be an intelligence check, but unlike saving throws npc's are supposed to CHOOSE to make the check, and many illusion spells state that this check is an action, so unless the illusion is literally unbelievable or doesn't make sense most NPCs should default to believing them.

Some DMs metagame this and that makes the illusionist crap, but a good DM is there for the experience and not to "win" in a game we're he's already God.

I mean, there are illusion spells that are can change the terrain of over a mile, or can create dragons, and you can literally make them real just by thinking, and can change them with just a thought as well.

You can pretty much become an in-game god.

[sophontteks]

As others said. If someone shot your wall, you did something wrong. You don't want to have your illusions getting attacked. If you know your enemy it can end encounters though. I have fond memories of chasing away some baddies with an illusionary ghast.

[Segev]

It is heavily DM-dependent, sadly, but as long as he's not meta-gaming...

Make that Barbarian have a blur spell on him. The arrow must have passed through the space obscured by the blur, right?

Make the wall a thick hedge-wall. The arrow just passed into it.

Drop that fog cloud on yourself and your allies, and have a coded phrase to let your allies know it's an illusion. At absolute worst, you and your allies must now spend an action disbelieving your own foggy illusion. More likely, the sure knowledge it's an illusion could give Advantage on the Investigation check, or even obviate it entirely.

Also, remember that the audio version of minor illusion is extremely flexible. You can have a silent image of a blur-enchanted barbarian charging, and have the minor illusion (audio version) you cast the round before provide the scream. Only the silent image requires Concentration.

[MrStabby]

AS a DM I play NPCs as PCs of the same int.

There is an unlikely effect. Judge if it is more likely real or illusory. As I rule I say there are more low level than high level casters in the world so there is a relative preference for believing the effect to be caused by the lower level spell, unless the NPC has experienced a high level spell from the party or other indication that they are high level (say like identifying high level loot on their persons, reputation etc.)

If you play every enemy dumb with no desire for self preservation then illusions are stupidly overpowered. If you meta-game and ignore them they are too weak. The trick is getting the right balance.

As for interactions I would say if you shoot an arrow through an illusion you know it is an illusion, but it doesn't follow that everyone else does. Either a tough spot check is required by the NPC or the person who knows that the effect is an illusion must communicate it - such things as silence spells will prevent this.

[sophontteks]

AS a DM I play NPCs as PCs of the same int.

There is an unlikely effect. Judge if it is more likely real or illusory. As I rule I say there are more low level than high level casters in the world so there is a relative preference for believing the effect to be caused by the lower level spell, unless the NPC has experienced a high level spell from the party or other indication that they are high level (say like identifying high level loot on their persons, reputation etc.)

If you play every enemy dumb with no desire for self preservation then illusions are stupidly overpowered. If you meta-game and ignore them they are too weak. The trick is getting the right balance.

As for interactions I would say if you shoot an arrow through an illusion you know it is an illusion, but it doesn't follow that everyone else does. Either a tough spot check is required by the NPC or the person who knows that the effect is an illusion must communicate it - such things as silence spells will prevent this.
Its because everyone sees the arrow pass through which would equal a successful int check. You've noticed a trait that the illusion shouldn't possess. It would be hard to believe something is a wall when your friends arrow went right through it.

Ofc you could say that some combatants arent looking at the wall. Perception checks may be in order for those already engaged.

[MrStabby]

Its because everyone sees the arrow pass through which would equal a successful int check. You've noticed a trait that the illusion shouldn't possess. It would be hard to believe something is a wall when your friends arrow went right through it.

Ofc you could say that some combatants arent looking at the wall. Perception checks may be in order for those already engaged.

Exactly - if you have the party barbarian in your face, trying to dodge blows and find your own opening for an attack the chances that you can catch that fleeting fraction of a second where the arrow passes through the illusion out of the corner of you eye are pretty slim.

[sophontteks]

Exactly - if you have the party barbarian in your face, trying to dodge blows and find your own opening for an attack the chances that you can catch that fleeting fraction of a second where the arrow passes through the illusion out of the corner of you eye are pretty slim.
Well, that would depend on its perception, and where the wall is relative to its facing. If an archer shot an arrow through a wall, every other archer would know garunteed. Same with anyone not engaged.

[Contrast]

Its because everyone sees the arrow pass through which would equal a successful int check. You've noticed a trait that the illusion shouldn't possess. It would be hard to believe something is a wall when your friends arrow went right through it.

Ofc you could say that some combatants arent looking at the wall. Perception checks may be in order for those already engaged.

I would personally be inclined to count the 'attack' as their investigation check, possibly made with advantage. Failure would represent either the arrow missing the illusion or them being distracted by the whirling combat after loosing the arrow and not noticing that it wasn't sticking out where it should be. I probably wouldn't let other people benefit from this in general situations though I could probably be convinced otherwise depending on the circumstances (obv if the person passes they can simply yell out to their friends).

Depending on the circumstances I'd probably upgrade to automatic detection after another round or two.

Of course the real question is why your archer is purposefully pegging arrows into a wall. That said, the trick to illusions is creating things the opponents do not want to interact with or will not be immediately obvious if interacted with - a ghost for example.

[Segev]

That said, the trick to illusions is creating things the opponents do not want to interact with or will not be immediately obvious if interacted with - a ghost for example.

Shadows (the monster) are a good choice, too. People will often just be glad they didn't get hit if the darned things "miss" a lot.

[Aaedimus]

I would personally be inclined to count the 'attack' as their investigation check, possibly made with advantage. ....Depending on the circumstances I'd probably upgrade to automatic detection after another round or two.

Of course the real question is why your archer is purposefully pegging arrows into a wall. That said, the trick to illusions is creating things the opponents do not want to interact with or will not be immediately obvious if interacted with - a ghost for example.

In the world of D&D as well, you have to remember that there are reasons other than illusions for arrows to go through walls. Mimics, Portals, etc. I would say unless they physically interact as stated in the spell, unless it's obvious it's an illusion, the weird interaction will trigger an intelligence check, not be the check. Advantage is not unreasonable.

[sophontteks]

It'd take some really stupid npcs to believe something is a wall when an arrow goes through it. Please explain this logic. What is going through there heads that they don't immediately think its an illusion, a level 1 spell.

[Segev]

It'd take some really stupid npcs to believe something is a wall when an arrow goes through it. Please explain this logic. What is going through there heads that they don't immediately think its an illusion, a level 1 spell.

"Did I miss? Where'd the arrow hit?"
"I didn't see it hit; it must have bounced off and be on the ground somewhere."
"That bramble-wall is so thick that I can't see any of the arrows I've fired into it!"

And that's just for "a wall."

For a creature?

"I didn't see him dodge, so I must have missed."
"That blur spell is really annoying!"
"Darn his dodging and weaving!"

Unless you assume that the archer is calmly watching where his arrow goes without any serious distractions on this battlefield, there are all sorts of reasons he'd wonder where his shot went wild rather than just assuming "it must have hit and gone straight through!" Actually watching it do so and assuming you saw what you think you did would be quite the perception check in most real combat situations. Generally speaking, people identify that a target has been hit by an arrow when they see the arrow sticking out of it, not by watching the arrow fly into it. If they see the target lacking a new set of feathers, the assumption is that it must have missed. In the heat of battle, nobody really has time to look around for where the arrow actually landed.

[tieren]

Make the wall wooden with 1000 arrowshafts already sticking out of it, maybe the fired arrow didn't go through and is now one of the ones sticking out. (bonus points if you ready a minor illusion "thunk" sound)

My personal favorite, had gnomish illusionist who carried around a satchel full of scrolls, with writing in bold letters that said in 3 languages (common, orcish, and goblin) "no pit trap here" or "fake wall".

Sometimes he would cover an actual pit trap with an illusion that included an identical sign, or make a fake wall illusion emblazoned with an identical sign. Other times he would just drop the signs or tack them to real walls to enjoy confusing the enemy. More effective than trying to create illusions of actual pit traps (which some DMs won't allow anyway).

[Segev]

Make the wall wooden with 1000 arrowshafts already sticking out of it.

Ooh, I like this one. Though harder to make "fit in" with a given environment.

Although, if that clues NPCs in to it being an illusion, you could start putting that up over real walls as a distraction to get them to waste time investigating.

[Sigreid]

For opponents other than the attacker I would use their passive perception based on a DC depending on how busy, obstructed, distracted they are to see the arrow pass through. Probably a 15 or so.

[Segev]

For opponents other than the attacker I would use their passive perception based on a DC depending on how busy, obstructed, distracted they are to see the arrow pass through. Probably a 15 or so.

The spell save DC would seem the most reasonable to me.

[Sigreid]

The spell save DC would seem the most reasonable to me.

Problem with that is that it's not about resisting the spell. It's a simple matter of whether they noticed the arrow pass through the barbarian.

[Segev]

Problem with that is that it's not about resisting the spell. It's a simple matter of whether they noticed the arrow pass through the barbarian.
The spell is never resisted. It is always a matter of seeing the inconsistencies. Hence an investigation action , not a wisdom or intelligence save.

[Sigreid]

The spell is never resisted. It is always a matter of seeing the inconsistencies. Hence an investigation action , not a wisdom or intelligence save.

I know. But unless the opponent in question is squaring off against the illusionary barbarian, in the heat of battle it would be challenging to notice that arrow passing through. I mean movie fighting is basically all about filming a missed attack from the right angle to make it seem like a hit.

[Segev]

I know. But unless the opponent in question is squaring off against the illusionary barbarian, in the heat of battle it would be challenging to notice that arrow passing through. I mean movie fighting is basically all about filming a missed attack from the right angle to make it seem like a hit.

My point was that "15" is often going to be easier than the actual DC of the spell. So you're giving, for free, a better chance of seeing through it than would be available to somebody who, made suspicious by something he'd seen, stopped to study it.

It's ultimately the DM's call what is sufficient "interaction" to trigger the auto-detection of the illusion's falsehood. Given that DMs generally seem to metagame illusions even when they don't mean to, as evidenced by how differently GM-controlled entities act around illusions cast by PCs than PCs act around illusions cast by GM-controlled entities (i.e., when the person controlling the acting character does or does not know the thing is only an illusion), I want to hold DMs to a higher standard than I want to hold players. Unless the DM, controlling the illusion and not having told the PCs it is one, would say, "Your arrow passes straight through," I would not be inclined to allow him to assume the same for his monsters. "Allow" being a strong word for "let pass without arguing with him about it."

In essence, unless the attack could not reasonably be believed to miss, I would assume that merely attacking an illusion results in insufficient interaction to reveal its falsehood. Sure, if you melee a wall (for some reason), you know you didn't feel a jarring response from your weapon striking where it should be. But if you arrow a wall from 30 feet away, unless you're taking the time to watch carefully and/or looking for where your arrow landed, it's reasonable to assume it just missed/bounced off and is on the ground somewhere.

If you've rolled, say, a natural 20 to hit that "barbarian," and you still miss? Yeah, you've definitely passed your weapon right through it and seen it wasn't really there. But otherwise, how are you sure you didn't just miss?

[Sigreid]

We aren't that far off. I was basically thinking that based on what I've seen it's a rare opponent that has a 15 or higher passive perception.

[Contrast]

In the world of D&D as well, you have to remember that there are reasons other than illusions for arrows to go through walls. Mimics, Portals, etc. I would say unless they physically interact as stated in the spell, unless it's obvious it's an illusion, the weird interaction will trigger an intelligence check, not be the check. Advantage is not unreasonable.

For clarity, when I said the attack counts as an investigation check, what I meant was if someone said they were attacking an illusion, I would ask them to roll investigation (they spent their action examining the object after all). So I think we're in agreement.

[sophontteks]

None of those reasons degrade the fact that they know the wall isn't real, and they are far too obscure. Would a player shoot an arrow through a wall and think anything other then "its an illusion". What monster would be thinking anything else?

[Aaedimus]

If you're using passive perception to decide if he sees the illusion than that's either an auto pass or fail depending on the character. Passive perception should be able to initiate the intelligence check but not replace it.

[Segev]

None of those reasons degrade the fact that they know the wall isn't real, and they are far too obscure. Would a player shoot an arrow through a wall and think anything other then "its an illusion". What monster would be thinking anything else?

What player would shoot an arrow at a wall for no reason? What is the reason, if not "none," for doing so? Is the player paying attention to what the arrow does, or is it going through the wall incidental and not necessarily in his focus of attention?

If a player believes the wall to be an illusion and is testing it, the illusion has mostly already failed. The arrow is just the player substituting a hopefully-easy attack roll for a harder Investigation check (because he still has to hit the wall) in order to confirm in a way that breaks the spell that it is an illusion.

The trouble arises when the GM, who must know that it's an illusion, since he knows everything about the scene and the player has to tell him what he's doing to cast it, has his monsters suddenly doing all the things necessary to test and discover the illusion. Why are they doing it? If you're justifying it rather than having already had planned to have them do that to other, non-illusory things, you're probably doing it wrong.

Would your monsters really try to charge through a stone wall that appeared out of nowhere? If the player cast wall of stone, would the monsters assume it was an illusion and behave the same way you're having them do when you know that's a silent image?

[Aaedimus]

That's actually a really good idea:
Being chased you throw up 2 silent images of stone walls. They figure it out and continue to chase you.
Than you cast wall of stone, and they assume this as well is an illusion.
That might stop the chase outright if it actually happened. They might even break a few bones depending on how fast they were running

[sophontteks]

What player would shoot an arrow at a wall for no reason? What is the reason, if not "none," for doing so? Is the player paying attention to what the arrow does, or is it going through the wall incidental and not necessarily in his focus of attention?

If a player believes the wall to be an illusion and is testing it, the illusion has mostly already failed. The arrow is just the player substituting a hopefully-easy attack roll for a harder Investigation check (because he still has to hit the wall) in order to confirm in a way that breaks the spell that it is an illusion.

The trouble arises when the GM, who must know that it's an illusion, since he knows everything about the scene and the player has to tell him what he's doing to cast it, has his monsters suddenly doing all the things necessary to test and discover the illusion. Why are they doing it? If you're justifying it rather than having already had planned to have them do that to other, non-illusory things, you're probably doing it wrong.

Would your monsters really try to charge through a stone wall that appeared out of nowhere? If the player cast wall of stone, would the monsters assume it was an illusion and behave the same way you're having them do when you know that's a silent image?

What player would shoot at a wall?
That wasn't the question. Don't strawman me.
The situation already occured and we are talking about what happened after. They clearly already suspect something, or the player is using the wall as cover. Right? Do we really need skill checks on top of this? I think its pretty clear that they know its an illusion.

Skill check-using intelligence to determine if the illusion isn't behaving like a real object, like seeing no shadow.

Interaction-doing something that proves the wall is an illusion.

Anyone who sees this doesn't need to bother with a check either. Its obvious.

[Segev]

What player would shoot at a wall?
That wasn't the question. Don't strawman me.
The situation already occured and we are talking about what happened after. They clearly already suspect something, or the player is using the wall as cover. Right? Do we really need skill checks on top of this? I think its pretty clear that they know its an illusion.

Skill check-using intelligence to determine if the illusion isn't behaving like a real object, like seeing no shadow.

Interaction-doing something that proves the wall is an illusion.

Anyone who sees this doesn't need to bother with a check either. Its obvious.

If the player is taking he action to deliberately try to see through the illusion, and there any question whether it counts as “interaction,” just have the action qualify as making an Investigation check.

Err on the side of it not being “interaction,” unless it’s so blatant that assuming it isn’t is ludicrous.

[sophontteks]

If the player is taking he action to deliberately try to see through the illusion, and there any question whether it counts as “interaction,” just have the action qualify as making an Investigation check.

Err on the side of it not being “interaction,” unless it’s so blatant that assuming it isn’t is ludicrous.
It is an interaction though, so we use the rules for interaction which is no roll...

Common sense rules. It makes no sense for any creature of reasonable intelligence to have to roll when they literally watched an arrow go through the illusion. What are they rolling for exactly? What does it mean when they fail? That they think arrows just go through walls sometimes?

[Voltage89]

It is an interaction though, so we use the rules for interaction which is no roll...

Common sense rules. It makes no sense for any creature of reasonable intelligence to have to roll when they literally watched an arrow go through the illusion. What are they rolling for exactly? What does it mean when they fail? That they think arrows just go through walls sometimes?
I think his point, which I actually agree with, is how do we know he saw the arrow go through the wall or target? Now, it being a wall makes it rather easy to see. However, it being a barbarian sprinting at him is different. The arrow could have gone through the barbarian or it could have went through, and in most cases you would assume he just dodged it.

[jas61292]

Getting illusions right is as much on the DM as on the players. Yes, it is important to have a good imagination and put in illusions that NPCs are actually likely to believe, but it is also important for the DM to play things fairly and not have the NPCs metagame. In the scenario presented in the OP of a wall, my first question would be: "why is he shooting at a wall?" And if the answer is "well, the wall just appeared in front of him," then my response would be "so, if I cast Wall of Stone, enemies will waste their next turns shooting at it, right? Sounds like a nice buff. I think I'll take it."

As mentioned earlier in the thread, its important to remember that D&D is a world filled with magic. This both means that there is more than one reason something might appear to have an arrow go through it, and that there is more than one possible explanation for the a phenomenon, including the sudden appearance of an object or creature. It takes a DM that both understands this, and understands that the NPCs understand this, in order for Illusions to work properly without being too weak or too strong.

[sophontteks]

I think his point, which I actually agree with, is how do we know he saw the arrow go through the wall or target? Now, it being a wall makes it rather easy to see. However, it being a barbarian sprinting at him is different. The arrow could have gone through the barbarian or it could have went through, and in most cases you would assume he just dodged it.
I agree there. I'd determine that with perception for anyone in melee. But anyone who saw an arrow go through the wall would know that its an illusion.

And the world is full of magic. So most creaures in the dnd world will know what a level 1 illusion spell is, as they are not rare. What would a player assume if their arrow went through a wall?

I garuntee their first thought is that its an illusion.

[Tanarii]

Physical interaction automatically reveals illusions that have that clause. No check. That's RAW. No "but can they tell", or tricking trying to make it foliage instead of a wall. It just happens. Even if it's an illusion of fog or mist, it happens when they are physically interacts with them. Which incidentally makes illusions of such things somewhat difficult to use well.

Things that aren't clear from RAW:
- who notices? Is it only the person physically interacting with them, or anyone that can see the interaction?
- does physical interaction make the illusion go faint so creatures can see through, or does that only happen on a successful intelligence check. The physical interaction clause and the int check clause can be read as separate clauses.

Personally I rule:
- the illusion is revealed to anyone that can see the physical interaction happen.
- it takes an action and an Int (Investigation) check to "discern" the illusion and be able to see through it, which is more than it just merely having it "revealed" by a physical interaction.

Edit: I'm aware the latter is a bit of a stretch interpretation of the RAW. But it's not absolutely clear, and I like the minor buff ruling it that way gives to illusions.

[Voltage89]

Physical interaction automatically reveals illusions that have that clause. No check. That's RAW. No "but can they tell", or tricking trying to make it foliage instead of a wall. It just happens. Even if it's an illusion of fog or mist, it happens when they are physically interacts with them. Which incidentally makes illusions of such things somewhat difficult to use well.

Things that aren't clear from RAW:
- who notices? Is it only the person physically interacting with them, or anyone that can see the interaction?
- does physical interaction make the illusion go faint so creatures can see through, or does that only happen on a successful intelligence check. The physical interaction clause and the int check clause can be read as separate clauses.

Personally I rule:
- the illusion is revealed to anyone that can see the physical interaction happen.
- it takes an action and an Int (Investigation) check to "discern" the illusion and be able to see through it, which is more than it just merely having it "revealed" by a physical interaction.

Edit: I'm aware the latter is a bit of a stretch interpretation of the RAW. But it's not absolutely clear, and I like the minor buff ruling it that way gives to illusions.
I think the thing is what counts as a physical interaction. I would think that means melee but it could be both.

[Tanarii]

I think the thing is what counts as a physical interaction. I would think that means melee but it could be both.
Yep, that's another question. It could mean personal / up close physical interaction. OTOH it does say the reason why is things passing through, so IMO throwing a rock at it or shooting an arrow should work fine.

[Voltage89]

Yep, that's another question. It could mean personal / up close physical interaction. OTOH it does say the reason why is things passing through, so IMO throwing a rock at it or shooting an arrow should work fine.
See, I do agree but in the thick if combat you could easily not see where your arrow actually goes

[Tanarii]

See, I do agree but in the thick if combat you could easily not see where your arrow actually goes
If you can't see where your arrow is going, then you'd be taking disadvantage on attack rolls.

[Voltage89]

If you can't see where your arrow is going, then you'd be taking disadvantage on attack rolls.
That's not true. If you make an attack you are not just going to stare at the target when other things are going on.

[Tanarii]

That's not true. If you make an attack you are not just going to stare at the target when other things are going on.Okay, now you're overthinking it. The rule is physical interaction reveals the illusion. Ruling you have to be able to see the physical interaction if its at a distance is reasonable. Even being able to clearly see (such as an arrow fired at an illusion 600 ft away) might be reasonable.

But trying to add a ruling based on facing or paying close enough attention isn't in the spirit of 5e. The assumption is you're paying attention in combat.

If you start ruling like that you're going to have to add "did you notice" checks all over the place in combat.

[Voltage89]

See, this is my reasoning. It is supposed to take an action to inspect the illusion to see if it is real or fake. However, an archer can use his action to attack 2 times. So, my illusion spell now only took half his action and is basically an auto success. I agree that if it is melee it would be obvious to tell.

[Avigor]

Hey everyone. I have a question about how you guys rule seeing through illusions. Let's say in combat I through up an illusion using silent or major image. The image is of a wall or maybe of a barbarian sprinting at the enemies screaming. Now, an archer shoots at the illusion and obviously, the arrow passes through. Would you say that just that enemy now knows it is an illusion, or that the other enemies do as well?


Oh, I also was wondering if anyone would make the person actually roll an attack against the illusion. The reason is the attack could miss the illusion, thus the attacker still not knowing whether it is an illusion or not.

Depends on how RAW you want to get. Illusion spells typically say that you must use an action to make an Intelligence (Investigation) check against the spell save DC to see through the illusion, and each individual attacker must do this separately; it doesn't give a RAW exception for an arrow going through the illusion allowing all who witness it to suddenly recognize the illusion for what it is, and in fact for at least phantasmal force RAW says that a creature will rationalize away any inconsistencies until they succeed at this check, so maybe all illusions mess with people's minds so if you see someone attacking through the wall you might perceive the arrow to go over the wall instead of through it if you haven't pierced the illusion yourself.

Granted, seeing something going through a wall should logically at least give you Advantage on the required check, unless you believe that said something can go through solid walls (5e does not yet have Brilliant Energy Weapons so I doubt this will ever be an issue for an attack, unless you're dealing with incorporeal creatures or a DM is willing to allow certain spells to bypass walls if one is using a Ring of X-Ray Vision to "see" the target and the witness of a spell going through the wall is aware that this can be a thing), and DMs are free to go ahead and just allow the illusion to become transparent once someone sees something going through it, so yeah it depends on the DM.

[Voltage89]

Depends on how RAW you want to get. Illusion spells typically say that you must use an action to make an Intelligence (Investigation) check against the spell save DC to see through the illusion, and each individual attacker must do this separately; it doesn't give a RAW exception for an arrow going through the illusion allowing all who witness it to suddenly recognize the illusion for what it is, and in fact for at least phantasmal force RAW says that a creature will rationalize away any inconsistencies until they succeed at this check, so maybe all illusions mess with people's minds so if you see someone attacking through the wall you might perceive the arrow to go over the wall instead of through it if you haven't pierced the illusion yourself.

Granted, seeing something going through a wall should logically at least give you Advantage on the required check, unless you believe that said something can go through solid walls (5e does not yet have Brilliant Energy Weapons so I doubt this will ever be an issue for an attack, unless you're dealing with incorporeal creatures or a DM is willing to allow certain spells to bypass walls if one is using a Ring of X-Ray Vision to "see" the target and the witness of a spell going through the wall is aware that this can be a thing), and DMs are free to go ahead and just allow the illusion to become transparent once someone sees something going through it, so yeah it depends on the DM.
I think that's actually a good idea. If you are not going to say that the other notice the arrow go through, hey should definitly get advantage on intelligence checks for that illusion.

[Tanarii]

it doesn't give a RAW exception for an arrow going through the illusion allowing all who witness it to suddenly recognize the illusion for what it is,Minor Illusion, Silent Illusion, and Major Illusion all say exactly that, that physical interaction reveals the illusion. No attempt to investigate is needed.

What it doesn't specify is that this also allows them to suddenly see through the illusion, as opposed to just knowing it's an illusion. Although that is the common interpretation of the physical interaction revealing the illusion rule.

[Voltage89]

Minor Illusion, Silent Illusion, and Major Illusion all say exactly that, that physical interaction reveals the illusion. No attempt to investigate is needed.

What it doesn't specify is that this also allows them to suddenly see through the illusion, as opposed to just knowing it's an illusion. Although that is the common interpretation of the physical interaction revealing the illusion rule.
We are saying that the interaction does revealed the illusion but the question is who is it reviled to? I would assume it means that it is just revealed to that player that acted with it.

[Tanarii]

We are saying that the interaction does revealed the illusion but the question is who is it reviled to? I would assume it means that it is just revealed to that player that acted with it.
Oh, sorry. Yes, it's a valid RAW question. Personally I answer that question as: anyone who can clearly see the physical interaction. But that's because it's explicit why, it's because physical objects pass through it. There's pretty clearly no "mess with minds" aspect for these illusion, unlike Phantasmal Force. But RAW doesn't explicitly specify it's anyone who can see the physical interaction.

[jas61292]

The issue is one of terminology. What is interacting? What is revealing? There is no clear RAW answer, and so DMs are left to their own discretion on this. Normally, I think DM discretion is a good thing, but I do wish this was a bit more specific.

Personally, I have always considered revealing to mean that the character is informed that it is an illusion. Appropriate investigation checks must still be made regardless to actually see through. Furthermore, I have always thought of interacting as meaning up close and personal, and not simply shooting or throwing something through it. That said, if someone did shoot an illusion, it would certainly give them a big clue that something is up. However, whether it is an illusion or some other magical effect would not be revealed to the character.

But, of course, I recognize the fact that this is just my own interpretation, and it is one that definitely helps power up illusions. And I like that.

[Segev]

It is an interaction though, so we use the rules for interaction which is no roll...

Common sense rules. It makes no sense for any creature of reasonable intelligence to have to roll when they literally watched an arrow go through the illusion. What are they rolling for exactly? What does it mean when they fail? That they think arrows just go through walls sometimes?


I think his point, which I actually agree with, is how do we know he saw the arrow go through the wall or target? Now, it being a wall makes it rather easy to see. However, it being a barbarian sprinting at him is different. The arrow could have gone through the barbarian or it could have went through, and in most cases you would assume he just dodged it.Indeed. My point is that, unless you're deliberately "shooting the arrow at the wall to watch and see if it passes through or not," or at least otherwise deliberately watching to see where, exactly, your arrow hits, there's an open question as to whether you'd be able to watch the arrow in flight and see that it did, in fact, pass into the wall without impact.

For example, if you're shooting an arrow at a wizard who is standing in front of the wall he just conjured up, and you miss, do we assume your arrow flew into the wall and passed through? Do we just assume you saw that, and get the "interaction" clause?

The "interaction" clauses' examples all involve very deliberate, very clear instances where the fact that the illusion provides no haptic feedback will make it painfully obvious that the illusion isn't really the solid object it appears to be. When the illusion is not of something from which haptic feedback would be expected, what then?

The "because things can pass through it" clause is important to understanding the "interaction" rule. If things passing through it is not strange, or you can't tell if they did or not, it doesn't qualify.

Incidentally, I just re-read major image (http://5e.d20srd.org/srd/spells/majorImage.htm), and discovered that it gives sensory illusions even up to temperature and smell. So an illusory wall of fire would feel hot as people approached. I wonder how many DMs would still have their monsters "test" the wall of illusory fire, because the DM knows what it is. Too many, I suspect. Even those not really trying to metagame will sometimes have trouble really putting themselves in the mindset of, "How would I have these act if it really was real?"


Getting illusions right is as much on the DM as on the players. Yes, it is important to have a good imagination and put in illusions that NPCs are actually likely to believe, but it is also important for the DM to play things fairly and not have the NPCs metagame. In the scenario presented in the OP of a wall, my first question would be: "why is he shooting at a wall?" And if the answer is "well, the wall just appeared in front of him," then my response would be "so, if I cast Wall of Stone, enemies will waste their next turns shooting at it, right? Sounds like a nice buff. I think I'll take it."

As mentioned earlier in the thread, its important to remember that D&D is a world filled with magic. This both means that there is more than one reason something might appear to have an arrow go through it, and that there is more than one possible explanation for the a phenomenon, including the sudden appearance of an object or creature. It takes a DM that both understands this, and understands that the NPCs understand this, in order for Illusions to work properly without being too weak or too strong.Well put. If I create an illusion of a Sphere of Annihilation, for example, will creatures test it, or flee from it? Will they behave the same if I actually happen to have one on hand and send it drifting towards them?


Okay, now you're overthinking it. The rule is physical interaction reveals the illusion. Ruling you have to be able to see the physical interaction if its at a distance is reasonable. Even being able to clearly see (such as an arrow fired at an illusion 600 ft away) might be reasonable.

But trying to add a ruling based on facing or paying close enough attention isn't in the spirit of 5e. The assumption is you're paying attention in combat.

If you start ruling like that you're going to have to add "did you notice" checks all over the place in combat.In combat, you're assumed to be paying attention to the combat. Not to every detail that happens on the field. You're relying on all your senses, too, especially for things other than your immediate foe.

Yes, if you're shooting specifically at that wall, with the intent of seeing where the arrow lands? You probably count as Interacting. But I'd be okay with a DM ruling that that doesn't count; instead, that counts as your stunt for your Investigation check. If you fail the check, you couldn't discern anything unusual about the arrow's behavior vis a vis the wall. Whether due to being unable to tell if it hit, or other factors.

This neatly resolves the question as to whether it should matter whether the wall is a stone wall, a wall of brambles, or an arrow-studded wooden palisade that would make it hard to tell if the arrow hit and where it "should" have.

I think it is fair to assume that no, nobody DID notice anything odd unless they actually took an action that would genuinely be telling. Attacking that barbarian and knowing you HAD to have hit him, for instance, rather than having room for doubt that maybe he dodged.

In fact, in combat, it might be fair to say you can't "interact" with it at all. That "interaction" is an out-of-combat thing. Otherwise, there's no need for the Investigation rule at all, since you can always find a way to make an action that you'd rather be taking if it turns out to be real into an "interaction."


I'd note that, if the illusionist is paying attention, many illusions offer opportunity to have them behave in a way that could at least conceal their nature from those watching another's interaction. If Bob tries to cross the illusory bridge, and Ivan the Illusionist makes it look like a whisper-quiet trap door opened up as soon as he stepped onto it, Bob's still likely to notice the lack of physicality to the structure as he screams and falls into the ravine, but Alice, watching nearby, sees Bob fall into a trap door. With major image, Ivan could even make the bridge just look and sound like the planks broke under Bob's footstep.

Because Interaction auto-penetrates the illusion, I think DMs are well-advised to treat it as the stop-gap against complete loss of suspension of disbelief, rather than as a low bar over which to step. If there can be reasonable question as to whether the characters would have noticed the inconsistency, don't treat it as interaction.

There are plenty of times when the inconsistency is so blaring that you have to imagine the character performing the possibly-interaction is actively looking for excuses to believe the illusion is real before you could buy that he's not figuring it out. Bob tries to pick up the bag of coins off the ground, and his fingers keep going through it. Alice leans on the illusory wall and falls through it. Charlie is stabbed through the chest by the orc and it does nothing.

Reducing the threshold of obviousness below that makes illusion spells nearly worthless. It also makes the need for the Investigation roll pointless, since one can obviate it by "interacting" instead of "Investigating."

[Tanarii]

I was working under the impression that we were discussing someone intentionally shooting an arrow at an illusion. If that's not the example, then what is the example?

Edit: there is no RAW way to determine if you shoot at someone partially behind cover if it hit the cover or not. So if thats the example, theres no way to determine if there was physical interaction with the illusion.

Also, it doesnt matter if its an illusion of fog or foliage or a solid wall. Physical interaction still reveals it. Thats RAW.

[Segev]

I was working under the impression that we were discussing someone intentionally shooting an arrow at an illusion. If that's not the example, then what is the example?In that case, I'd count it as their Investigation check. If they roll over the spell's DC, then they conclusively saw the arrow pass through the wall. If they didn't, they were distracted, or lost sight of the arrow, or can't tell if it went through the wall or is sticking out of it, or any number of other things that would make the test fail.

If they walked up and thrust their sword (or bow, or an arrow) into the wall, personally, I'd count that as interaction because it crosses the threshold of "there's no way you could mistake that."


Edit: there is no RAW way to determine if you shoot at someone partially behind cover if it hit the cover or not. So if thats the example, theres no way to determine if there was physical interaction with the illusion.Good point. I agree. This is the same reason I question whether any action not taken with deliberate intent to test the illusion's reality would have a means of determining if you interacted with it or not. If there's any question at all, either it fails to reveal it, or it deserves the Investigation check. (Depending on whether the action had any other consequences on which the character might be focused. If he wasn't trying to test the illusion, and his action has other consequences besides testing the illusion, I wouldn't give it to him. Investigation specifically takes its own action.)


Also, it doesnt matter if its an illusion of fog or foliage or a solid wall. Physical interaction still reveals it. Thats RAW.

The RAW is actually, "Physical interaction with the image reveals it to be an illusion, because things can pass through it." You only get to ignore the second clause if you're ignoring half of what's written in the rules as written.

If you want to get that legalistic, you're already failing 5e, which is (sometimes frustratingly) intentionally open-ended and conversational in its intended interpretations. But given that they spent the words to clarify why "physical interaction with the image reveals it to be an illusion," ignoring that text in order to make it not matter whether things going through it should be indicative is pretty much the opposite of 5e's design philosophy.

And regarding the hedge or the wall bristling with arrows, it's like an illusion of a chainlink fence: can you be sure you saw the arrow go through it? Or did it pass through a hole, or is it one of those arrows sticking out of it?

If you say, "it doesn't matter; it went through it whether you saw it or not," does that mean that an illusion of a 10-foot block of wood becomes obviously an illusion if anybody hides inside it, because they're physically interacting with it, even though others can't see them doing so unless they saw them enter it?

Your interpretation, which requires ignoring the second clause of the sentence you're quoting, makes illusions next to useless and makes the entire set of rules involving rolling Investigation checks pointless.

[Aaedimus]

This^^^^
Also that's why I said talk to the DM before v focusing on illusions. It's OP and fun when played by the rules, but if your DM is going to metagame the illusions or auto fail the checks than it's not worth the pain of trying to lawer it into the game.

Most DMs I've played with have tried to accommodate realistically, than again we're all in our mid to late twenties and have a level of maturity.

[Tanarii]

In that case, I'd count it as their Investigation check. If they roll over the spell's DC, then they conclusively saw the arrow pass through the wall. If they didn't, they were distracted, or lost sight of the arrow, or can't tell if it went through the wall or is sticking out of it, or any number of other things that would make the test fail.

If they walked up and thrust their sword (or bow, or an arrow) into the wall, personally, I'd count that as interaction because it crosses the threshold of "there's no way you could mistake that."Why? I can't see how that wouldn't count as "physically interacting". Which, RAW, automatically reveals the illusion.


Good point. I agree. This is the same reason I question whether any action not taken with deliberate intent to test the illusion's reality would have a means of determining if you interacted with it or not. If there's any question at all, either it fails to reveal it, or it deserves the Investigation check. (Depending on whether the action had any other consequences on which the character might be focused. If he wasn't trying to test the illusion, and his action has other consequences besides testing the illusion, I wouldn't give it to him. Investigation specifically takes its own action.)No it's not. It's a different question. If you intentionally interact with it, you intentionally interact with it.


The RAW is actually, "Physical interaction with the image reveals it to be an illusion, because things can pass through it." You only get to ignore the second clause if you're ignoring half of what's written in the rules as written.I'm not ignoring anything. An arrow shot at, or a creature walking through, an illusion of fog or foliage is passing through it and physically interacting with it. So it's automatically revealed.


If you want to get that legalistic, you're already failing 5e, which is (sometimes frustratingly) intentionally open-ended and conversational in its intended interpretations.I am not being legalistic at all. I'm pointing out what it does say, and what it doesn't say. And what it doesn't say is already plenty vague to allow differing interpretations. But what is clear is clear. Physical interaction reveals the illusion. It even tells you why. Because things pass through it.

I mean, house rule away if you don't want that. But that part is about as clear as it can be.

[CharonsHelper]

I agree there. I'd determine that with perception for anyone in melee. But anyone who saw an arrow go through the wall would know that its an illusion.

And the world is full of magic. So most creaures in the dnd world will know what a level 1 illusion spell is, as they are not rare. What would a player assume if their arrow went through a wall?

I garuntee their first thought is that its an illusion.

You explained it here -


And the world is full of magic.

And not just illusionary magic.

What if it's a wall which allows unliving things to pass through? Or they have to be going at least 100mph. Or it's a mimic which you just hit. Or...

There are a lot of weird magical reasons that an arrow MIGHT go through a wall in a D&D game.


Anyway - I mostly popped in here to say that one of my personal favourite things as an illusionist is to make REALLY BAD illusions which make the enemy do stupid things. My favourite was when we were in a dungeon and there happened to be a chasm behind us. As we heard the enemy coming up from behind, I quickly made a cartoony looking chasm slightly larger than the real one with one of the party members standing on it.

The enemy rolled their eyes at my illusion and proceeded to charge us... and then falling into the real chasm.

[Segev]

Why? I can't see how that wouldn't count as "physically interacting". Which, RAW, automatically reveals the illusion.Did it pass through the illusion, or through the holes in the illusion?


No it's not. It's a different question. If you intentionally interact with it, you intentionally interact with it.So...the writers were idiots wasting word count when they included the text dedicated to spelling out the Investigation check and its DC? Since you automatically pierce the illusion when you interact with it, even if you do as part of another action or a non-action, and thus standing there staring at it while making an Investigation check (without somehow actually interacting with it, since if you did that, you wouldn't need the check) is wasting 1+ actions that are not necessary to get the same effect. Am I understanding you correctly?


I'm not ignoring anything. An arrow shot at, or a creature walking through, an illusion of fog or foliage is passing through it and physically interacting with it. So it's automatically revealed.You're ignoring the comma, the word "because," and everything from there to the period at the end of the sentence.


I am not being legalistic at all. I'm pointing out what it does say, and what it doesn't say. And what it doesn't say is already plenty vague to allow differing interpretations. But what is clear is clear. Physical interaction reveals the illusion. It even tells you why. Because things pass through it.You're being legalistic by focusing on the words you want to pay attention to, and ignoring the second clause of the sentence, dismissing it for whatever reasons you choose to dismiss it. Treating the second clause as anything but an explanation that clarifies when and how "physical interaction" is meant to be understood to be revealing the illusion is legalistic reading.

It is as clear as can be that that sentence is meant to convey that you aren't fooled by the illusion if you try to touch, move, or strike it and fail to feel anything and see your hand/weapon/whatever pass right through it. There is no reason this "because" would make sense with an illusion of fog or anything else where you cannot tell whether the thing you're observing "going through" the illusion is doing anything unusual.

You are, of course, free to ignore half of the sentence in order to get the interpretation you want, but again, that makes the Investigation check utterly pointless as a rule. Anything you might try to investigate the thing you suspect to be illusory will involve physical interaction.

Heck, by your reading, illusions fail upon casting. The air physically interacts with them.

[Aaedimus]

So you're saying, if you shoot a chainlink fence from 80 feet away with an arrow that qualifies as "physical interaction"?

Or if you see a dog walk through that same fence?

Unless you're (you are) physically interacting personally (your hand goes through it) it's an intelligence check because there are a thousand ways for that weird thing to happen, and only some of them are because illusion.
It could even provide advantage, but the creature seeing it happen needs to use their intelligence to be like: hmmm... that didn't make sense.
And the reason they come up with might not be right.

Yes, for SOME illusions, physical interaction is an automatic success. But, don't be a rude DM, and have the NPCs act weird so that every illusion is accidentally discovered. And not every illusion rates an intelligence check.

[Segev]

Actually, I have a good example to illustrate why "arrow through wall" doesn't really meet the bar for "interaction."

Well, sequence of scenarios, at least.

Scenario 1: Classic Illusory Wall Shot By Arrow
This is what we've been discussing. For whatever reason, a real arrow is shot at an illusory wall. It does go through it. The involved characters may or may not have recognized what happened.

Scenario 2: Real Wall Shot By Illusory Arrow
Bob sees the orc shoot the wall! The orc's arrow passes through the wall. Does Bob now believe the wall to be an illusion? Of course not. Does he know the arrow to be? Maybe, but he can't see it anymore to confirm whether it's now translucent to him.

(Incidentally, the fact that he could "check" the arrow to see if it is translucent, rather than his knowledge of its illusory nature making it translucent, is one of the major problems I have with the "any physical interaction, no matter how weak or hard to confirm" interpretation.)

Scenario 3: Illusory Wall Shot By Illusory Arrow
Bob sees the orc shoot the wall! The orc's arrow passes through the wall (perhaps they were created by different illusionists, or the illusionist messed up somehow). Does Bob know the wall to be illusory? The arrow? Neither? Both? Why? Technically, neither physically interacted with the other, but this in no way looks different than Scenarios 1 and 2 to Bob.

Scenario 4: Real Wall Shot By Exceptionally Talented Stage Magician
Bob watches the orc (whose dapper top hat confuses him a bit) shoot the wall. Bob is 100% convinced that the arrow passed through the wall, because the orc is a very talented sleight-of-hand artist who managed to trick Bob into believing this. Does Bob now believe the wall to be illusory? Or the arrow? Well, since they're not illusions, he can't see through them, so...I guess not.

Scenario 5: Illusory Wall Shot By Exceptionally Talented Stage Magician
Bob watches the orc (whose dapper top hat confuses him a bit) shoot the wall. The magician acts exactly as he would in Scenario 4, so the arrow convinces Bob it passed through the wall, but it no more did so now than it did in Scenario 4 (where, recall, the wall was real). Is Bob now able to see through the illusory wall because he was convinced by the stage magician's performance?

Scenario 6: Real Ghost Emerges From Real Wall
Bob sees this happen. Is he convinced the ghost is illusory? It's translucent, after all...

Scenario 7: Real Ghost Emerges From Illusory Wall
Bob sees this happen. Does he know the wall is an illusion, because the ghost emerging made it translucent?

Scenario 8: Illusory Ghost Emerges From Real Wall
Bob sees this happen. Does he know the ghost to be illusory because he saw it interact with the wall?

Scenario 9: Illusory Ghost Emerges From Illusory Wall
Bob sees this happen. Did the illusory ghost interact with the illusory wall physically? Are either instantly revealed?





If, after the events above, Bob can go and look at the things involved and see if they're now translucent or not in order to determine which are illusions, then this is very silly. It fails any sort of reasonable consistency check. If told "at least one of this arrow and this wall are illusory," and then one is passed through the other, one can tell which is the illusion automatically by virtue of which turns translucent, that flies in the face of the reasoning given for the interaction clause, which is, "because things can go through it." It doesn't say, "because physical contact disrupts the illusion." It says, "because things can go through it."

The interaction therefore must be a) on the part of the creature to gain knowledge of the illusion's true nature, and b) directly physical, not indirectly so (e.g. arrow into wall). Too many other weird things can get involved that could be happening if it's not very, very direct physical interaction.

Heck, one could argue - I just thought of this, so I haven't been working up to it or anything - that poking it with a stick or shooting it with an arrow isn't physically interacting. It's not YOU physically interacting. It's the stick, or the arrow. So now the stick or the arrow know it's an illusion; all you know is something made them pass through each other. You've got to feel it for yourself. Physically interact, yourself.

Not really going to hold fast to that argument, but it's one way to be consistent without having to figure out how to argue that the air physically interacting with an illusion doesn't instantly reveal it to be illusory to everybody.

[sophontteks]

Physical interaction is any interaction caused by you that is physical.
When I poke a corpse with a stick. I am physically interacting.
When I shoot a duck with a gun. I am physically interacting.

Everything else is just additional words you've added to make a first level spell stronger then it already is. It doesn't say at all that you must touch it, or contact it, or anything of the sort.

Seeing as shooting the illusion is an action and I still haven't heard any compelling reason to believe that an arrow going through a wall doesn't lead to everyone believing that the wall isn't real, they physically interacted, they still got value out of a first level spell, but the jig is up.

Any player would assume its an illusion as well.

[Segev]

Physical interaction is any interaction caused by you that is physical.
When I poke a corpse with a stick. I am physically interacting.
When I shoot a duck with a gun. I am physically interacting.

Everything else is just additional words you've added to make a first level spell stronger then it already is. It doesn't say at all that you must touch it, or contact it, or anything of the sort.

Seeing as shooting the illusion is an action and I still haven't heard any compelling reason to believe that an arrow going through a wall doesn't lead to everyone believing that the wall isn't real, they physically interacted, they still got value out of a first level spell, but the jig is up.

Any player would assume its an illusion as well.

So, you're ignoring the question of whether they actually could confirm they saw the arrow pass through the wall.

You say I'm trying to make the spell "stronger than it already is," but the mechanisms that count as "physical interaction" that automatically pierce it seem to me to make the spell 100% useless. It cannot fool anybody, and even if it did, they'd not even have to waste an action to be un-fooled and see the truth.

The mechanisms proposed also render the entire part of the spell that mentions Investigation checks pointless, since anything you'd do to investigate it would qualify as "interaction." There's literally no reason to say, "I take an Investigation action," rather than "I throw a copper piece at it."

I notice, too, that you fail to address any of the scenarios. Does a ghost walking through an illusory wall make all observers know the wall is illusory? What if the ghost is also an illusion? Does an illusory man walking through a real wall reveal the man to be the illusion of the two? Does a real man walking through an illusory wall reveal the wall to be the illusion? How do observers tell which is which?

What about an illusory man walking through an illusory wall?

Edit: My point isn't that you need to make an Investigation check after seeing an arrow fly through a wall. My point is that the action of firing the arrow probably qualifies as your Investigation check, and that you need to make said check to confirm sufficiently that the arrow really did pass through the wall. Fail the check, and you either didn't see where the arrow went, or you saw it do something believable for how you lost track of it. Pass it, and you clearly saw the arrow pass through the wall as if the wall wasn't there.

[sophontteks]

So, you're ignoring the question of whether they actually could confirm they saw the arrow pass through the wall.

You say I'm trying to make the spell "stronger than it already is," but the mechanisms that count as "physical interaction" that automatically pierce it seem to me to make the spell 100% useless. It cannot fool anybody, and even if it did, they'd not even have to waste an action to be un-fooled and see the truth.

The mechanisms proposed also render the entire part of the spell that mentions Investigation checks pointless, since anything you'd do to investigate it would qualify as "interaction." There's literally no reason to say, "I take an Investigation action," rather than "I throw a copper piece at it."

I notice, too, that you fail to address any of the scenarios. Does a ghost walking through an illusory wall make all observers know the wall is illusory? What if the ghost is also an illusion? Does an illusory man walking through a real wall reveal the man to be the illusion of the two? Does a real man walking through an illusory wall reveal the wall to be the illusion? How do observers tell which is which?

What about an illusory man walking through an illusory wall?

Edit: My point isn't that you need to make an Investigation check after seeing an arrow fly through a wall. My point is that the action of firing the arrow probably qualifies as your Investigation check, and that you need to make said check to confirm sufficiently that the arrow really did pass through the wall. Fail the check, and you either didn't see where the arrow went, or you saw it do something believable for how you lost track of it. Pass it, and you clearly saw the arrow pass through the wall as if the wall wasn't there.
I'm not this is the fourth time I have now mentioned a perception check and stressed that its everyone who saw the interaction. Please. I can't present a reasonable debate if you do not read what I write.

Also as mentioned. Why would anyone shoot a wall in the first place? If your illusion is under this scrutiny it was a bad illusion. You present illusions into situations where they are believable rsther then hope the enemy wastes their time rolling for what they already seem to believe isn't real.

As for your other scenarios. We are talking about a real arrow going through an illusionary wall. This is just an attempt to change the subject.

[Segev]

I'm not this is the fourth time I have now mentioned a perception check and stressed that its everyone who saw the interaction. Please. I can't present a reasonable debate if you do not read what I write.

Also as mentioned. Why would anyone shoot a wall in the first place? If your illusion is under this scrutiny it was a bad illusion. You present illusions into situations where they are believable rsther then hope the enemy wastes their time rolling for what they already seem to believe isn't real.Sorry; I'm arguing with more than one person, here, and a lot of these points aren't really arguments against my position if you're accepting you need to be able to see it.

I disagree on allowing a non-active Perception check, or using Perception at all, since the mechanics of the spells in question all specify taking an action for an Investigation check.

Yes, if somebody is deliberately shooting a wall, I'm going to count that as the Investigation check's action and let them make the roll. If they're that suspicious of the wall's reality, then it probably has already failed.

What I'm further arguing against, however, is the notion that even "physical interactions" that don't involve situations where things passing through it would be obviously wrong still trigger the first half of the "physical interactions" sentence despite not making sense with the second half.

Imagine, for a moment, a spell called "Phantasmal Phantom" which does nothing but make the illusion of a ghost. Now, imagine if it had this line: "Physical interaction between the illusory ghost and solid objects instantly reveal it to be an illusion, since it can go through solid objects and they go through it." Would that line make any sense at all? Would you expect to see such a line in a spell of that description, or would such a line surprise and confuse you?

It would make me wonder what the writer was thinking. While 5e writers are hardly perfect, I do tend to give them the benefit of a doubt when I read the rules and there is an interpretation that lets me think, "Ah, this is what a rational and sensible human being meant me to take away from what they wrote, here." I have no such reaction to the above hypothetical description, because the notion that a ghost going through solid objects makes it obvious the ghost is an illusion is silly.

The actual text that Tanarii keeps harping on has text he's actively ignoring immediately following it: "because things can go through it." If the illusion is of something that things going through would not be odd, then we are to understand that the "instant revelation" of its illusory nature would not happen.

Imagine if I were telling you about gravity in an atmosphere. "Things fall near the surface of the Earth, because they're heavier than the air around them." Does this mean that helium balloons plummet to the ground on Earth? After all, "Things fall near the surface of the Earth."

The "because" clause is important. It tells us why we expect the first part to be true. It also tells us, by implication, WHEN it is true. If things going through the illusion wouldn't reveal anything unusual about it, then the illusion is not revealed. That is the only sensible way to read the RAW; reading it the way Tanarii wants to requires there to be some sort of "oops, I've been touched, time to go translucent!" property to the illusions, rather than the translucence being a consequence of the perception of the observer who knows for a fact it is an illusion.


As for your other scenarios. We are talking about a real arrow going through an illusionary wall. This is just an attempt to change the subject.No, it's an attempt to illustrate the problems with the underlying logic.

We're discussing what the rule actually means. I'm not denying that a real arrow, successfully witnessed unquestionably passing through an illusory wall, reveals (to the observer) that the wall is an illusion. I am saying, however, that it still requires the roll for Investigation (but spending the action specifically watching that arrow's trajectory qualifies for the action required to make the Investigation roll) to be certain you saw what you think you saw.

The other scenarios illustrate why ambiguity exists, and how always assuming that the wall is revealed to be illusory because obviously it must be (so much so that it obviates the need to roll or even - potentially - spend the action on detecting it) is a flawed assumption.


I also argue, still, against Tanarii's assertion that the rules specify that, even if the arrow flying into the illusion would in no way be obviously unusual if the illusion were instead real. It requires ignoring the "because" statement, and doing so turns statements like, "Helium balloons rise, because they're lighter than air," into a declaration that helium balloons would rise against gravity on the Moon, or in a vacuum chamber, or in a chamber filled with hydrogen. (That last one I bring up to curtail any "it would pop" dodges of the point.)

Alternatively, "Solid objects that sit on top of H2O are less dense than the H2O upon which they sit, because objects float in fluids that are less dense than said objects are," now apparently means that putting a bar of gold on top of a block of ice means that the bar of gold is less dense than the block of ice.

As nonsensical as the above paragraph's claim is, that is the same logic being applied by Tanarii when he ignores the "because" clause explaining why physical interaction reveals the illusion.

[Tanarii]

So...the writers were idiots wasting word count when they included the text dedicated to spelling out the Investigation check and its DC? Since you automatically pierce the illusion when you interact with it, even if you do as part of another action or a non-action, and thus standing there staring at it while making an Investigation check (without somehow actually interacting with it, since if you did that, you wouldn't need the check) is wasting 1+ actions that are not necessary to get the same effect. Am I understanding you correctly?
They are not idiots. It is not wasting your action. It is intentionally NOT physically interacting with it. Physically interacting at a distance may not be possible, may not result in a desired outcome, and most importantly in D&D that may be stupidly dangerous thing to do, triggering very negative results.

Not to mention that RAI, its possible physical interaction may not be intended to make the illusion faint and see through.

So no, aparently you don't understand.

[Segev]

They are not idiots. It is not wasting your action. It is intentionally NOT physically interacting with it. Physically interacting at a distance may not be possible, may not result in a desired outcome, and most importantly in D&D that may be stupidly dangerous thing to do, triggering very negative results.Throwing a rock or shooting an arrow or poking with a stick isn't exactly endangering you.

If you're talking about illusions of creatures, we have yet another discussion over at what point physical interaction is occurring. Because by your definition of it, I see no way in which you're at risk until it does something that physically interacts with you, and then you still have your standard defenses AND get to know instantly it's illusory because of the interaction.


Not to mention that RAI, its possible physical interaction may not be intended to make the illusion faint and see through.

So no, aparently you don't understand.So... the RAI, which match the RAW if you read the whole sentence rather than just the part before the comma, are what I've been saying they are...and this shows that I do not understand the RAW or the RAI? You're right about one thing: I am not understanding what you're saying.

[Voltage89]

To be honest, I really agree with a good bit of what both of you are saying. I do agree that maybe by RAW, something passing through a ghost may reveal that it is an illusion. However, that is most likely something that the game creators simply looked over. We then need to look at common knowledge and logic to discern whether or not the object is an illusion.
We simply need to look at whether or not it makes sense. If it was a real ghost, then the arrow or object would have gone through the ghost. So, it would do the same for an illusionary ghost.
I think that using an illusionary wall of fire could be cool for battle control. But then, if the goblin shoots an arrow at me through the fire, they technically now know that the wall of fire is an illusion. The thing is, that makes absolutely no sense at all.

[JackPhoenix]

To be honest, I really agree with a good bit of what both of you are saying. I do agree that maybe by RAW, something passing through a ghost may reveal that it is an illusion. However, that is most likely something that the game creators simply looked over. We then need to look at common knowledge and logic to discern whether or not the object is an illusion.
We simply need to look at whether or not it makes sense. If it was a real ghost, then the arrow or object would have gone through the ghost. So, it would do the same for an illusionary ghost.
I think that using an illusionary wall of fire could be cool for battle control. But then, if the goblin shoots an arrow at me through the fire, they technically now know that the wall of fire is an illusion. The thing is, that makes absolutely no sense at all.

Considering that real Wall of Fire do enough damage to destroy the arrow passing through, it makes perfect sense that the wall that doesn't do that isn't real.

And you can beat 5e ghosts to proper death with a stick, if you want to, and the ghosts take damage if they stay inside solid objects too long, so they clearly aren't as inconporeal as they should be.

[Segev]

Considering that real Wall of Fire do enough damage to destroy the arrow passing through, it makes perfect sense that the wall that doesn't do that isn't real.

And you can beat 5e ghosts to proper death with a stick, if you want to, and the ghosts take damage if they stay inside solid objects too long, so they clearly aren't as inconporeal as they should be.

The goblins firing the arrow through the illusory wall of fire don't see the arrow fail to be consumed. It might convince Voltage89 that the firewall is illusory, but if he put the illusion up in the first place, that's probably not news to him.

5e ghosts can still walk through walls. Having one step out of a wall instantly reveal that the ghost is an illusion because the ghost appears to have stepped through the wall is still rather ridiculous. It changes the obviously-intended paradigm of "realization that the thing is an illusion makes it translucent to you" to a paradigm of "the illusion turns translucent to you for arbitrary but defined reasons, and that reveals to you that it is an illusion."

[JoeJ]

Considering that real Wall of Fire do enough damage to destroy the arrow passing through, it makes perfect sense that the wall that doesn't do that isn't real.

A Wall of Fire doesn't do any damage to arrows. The spell description says it affects creatures, not creatures and objects. It's also opaque, so there would be no way the archer could know whether their arrow was consumed or simply passed through.

[Tanarii]

Throwing a rock or shooting an arrow or poking with a stick isn't exactly endangering you.That is something very specific to your games. I've been in plenty of games, and run plenty of games, where choosing to shoot an arrow / throw a rock /poke a stick at something because you think it might be an illusion is definitely going to endanger you.

[Brightersidegam]

This is all very confusing. Fitting for illusions, but I'll add my two cents. Since we seem so hung up on the arrow and wall illusion, we'll use that, and of course, DMs may differ, that's why this discussion is so heated, isn't that so awesome? Bear with me, this is a long one.

Let's take a look at what the book says:

"Physical interaction with the image reveals it to be an illusion, because things can pass through it. A creature that uses its action to examine the image can determine that it is an illusion with a successful Intelligence (Investigation) check against your spell save DC. If a creature discerns the illusion for what it is, the creature can see through the image."

(This is for silent image, also, I'm writing this on my phone and don't feel like using the quote things, sorry)

So, first sentence, physical interaction (in this case, the arrow) reveals it (the wall) to be an illusion... Seems straight forward until you notice the comma... , because things can pass through it. Huh, that last bit is what throws people through a loop, what about a fog, bramble, or chain link fence? Arrows go through those (usually). Some DMs might let this go, the arrow went through the fog BECAUSE it's fog, not BECAUSE it's an illusion. Others might say that it gives a noticeable aura as the arrow passes through, revealing it's true nature because things can go through it, something I haven't heard mentioned which is a possibility that could reveal a lot of these incorporial walls (a ripple, a small flash, an audible "voip" sound). Still, because the physical action went through the illusion, it is revealed to be such because passing through things happened (again, apparently). If I were to choose a side, I'd pick the latter, if only for the fact that, if it's not the fact, then silent image can mimic other spell effects (like fog cloud, or even darkness, for instance) to no real detriment, making it far superior (why take fog cloud if silent image does the same thing?)

Next is the investigation check, basically it's the same as physically interacting with it, except for not physically interacting with it (i don't want to touch the fire, but use my other senses to inspect it). No range is given, but most imagine investigation to be an "up close," thing (rarely it might be given at a range.) A successful check reveals the image.

Finally, the last sentence, if a creature descerns the illusion for what it is, it can see through it. Honestly, talking is a free action. Arrow McShooty fires through wall, or Sherlock Holmes deduces the wall to be fake, then tells everyone "That wall is but an illusion! It is not real!" Now everyone knows. Is it revealed to all creatures? Maybe not, maybe so, still, everyone knows now, and the effectiveness is not nearly as useful now.

Honestly, I have so much more on how things could be ruled differently, but that's enough of a wall of text (a spell I'm very familiar with), so I might add that later.

This is an interesting discussion, though, and something I should bring up with my DM. We haven't actually used illusory terrain in our games, so it might be a good time to bring it up, before we do.

[Unoriginal]

Just to say: the whole point of Illusions is to fool Perception. That's why INT (Investigation) is used: it seems true, your eyes are telling you it's true.

[Glorthindel]

I consider all this quibbling about wording pretty pointless. There is one simple way to determine if how it is being adjudicating is fair, and that is to swap your position with the player/DM.

For those arguing from the position of a player, that an NPC shooting an arrow at a wall would not reveal an illusion, flip the script, and place yourself (as a player) shooting an arrow at a wall conjured by a monster. If you are telling me that you would accept a DM saying "sorry, you can't tell if the arrow went through the wall or not, you still have to make an Investigation check" without calling bull****, I have my doubts. Likewise, if another player revealed an illusion in that manner, if you are saying you would accept a Dm saying "no, only that character is aware it is an illusion, you must still act under the impression it is a real wall", I am going to again be sceptical.

Regardless of your choice of ruling, as long as you would apply the rule the same way if it was used by a DM, as you would if it was used by a player, then in my opinion you are ruling fair. But if you are expecting DM's to jump through additional hoops you wouldn't accept as a player (or visa versa), then you aren't.

This is obviously aside from any metagaming issue - if the DM is metagaming and using his knowledge that it is an illusion to circumvent it by having NPC's make unexplainable decisions (like shooting at a wall in the first place), then that is obviously wrong.

[CharonsHelper]

If you are telling me that you would accept a DM saying "sorry, you can't tell if the arrow went through the wall or not, you still have to make an Investigation check" without calling bull****, I have my doubts. Likewise, if another player revealed an illusion in that manner, if you are saying you would accept a Dm saying "no, only that character is aware it is an illusion, you must still act under the impression it is a real wall", I am going to again be sceptical.


You can be sceptical & straw-man all you want. But that's the way that I'd want to play it.

But I do agree with your general sentiment that this is largely a table issue. Basically - before playing an illusion focused character, sit down with your GM & ask how they plan to rule such things.

I know that the table variation is why I don't play any illusion-based characters in any sort of organized play.

[Segev]

Why take fog cloud rather than silent image? Duration and area. A high-level casting of it can cover a good several city blocks, or an entire manor. Any level casting of it provides an hour of cover, rather than the minute(s) you can get from silent image. And, should anybody become suspicious of your "fog cloud" (perhaps due to you and your allies not blundering around as if the world were heavily concealed), they can make an Investigation check to see through the silent image of one, but would be wasting their action in a real one. (Of course, negating the heavy obscurement for yourself and your allies is a higher cost if it's real, too.)

I consider all this quibbling about wording pretty pointless. There is one simple way to determine if how it is being adjudicating is fair, and that is to swap your position with the player/DM.

For those arguing from the position of a player, that an NPC shooting an arrow at a wall would not reveal an illusion, flip the script, and place yourself (as a player) shooting an arrow at a wall conjured by a monster. If you are telling me that you would accept a DM saying "sorry, you can't tell if the arrow went through the wall or not, you still have to make an Investigation check" without calling bull****, I have my doubts. Likewise, if another player revealed an illusion in that manner, if you are saying you would accept a Dm saying "no, only that character is aware it is an illusion, you must still act under the impression it is a real wall", I am going to again be sceptical.

Regardless of your choice of ruling, as long as you would apply the rule the same way if it was used by a DM, as you would if it was used by a player, then in my opinion you are ruling fair. But if you are expecting DM's to jump through additional hoops you wouldn't accept as a player (or visa versa), then you aren't.

This is obviously aside from any metagaming issue - if the DM is metagaming and using his knowledge that it is an illusion to circumvent it by having NPC's make unexplainable decisions (like shooting at a wall in the first place), then that is obviously wrong.

Given that the rules for illusions call for Investigation checks that the character must proactively make, if I am suspicious of the wall being an illusion and cannot or will not for some reason walk up and try to push my hand against it, I'd be perfectly fine with the DM requiring me to make that Investigation check. Shooting an arrow at it or otherwise forcing a "physical interaction" to auto-pass the (what amounts to a) saving throw for the spell is cheesy at best, and probably trying to bend the rules to cheat the system. (Not that I have an inherent problem with cheese, but I do have a problem with it being used to make something of questionable utility less useful.)

If I were suspicious of that fog cloud being an illusion rather than the caster having actually conjured the fog, I would expect the DM to make me make an Investigation check rather than allowing me to declare, "I disbelieve, so I can see through it."

Heck, the only time, as a player, I would expect to get a free pass on seeing through an illusion that wasn't blatantly obvious (by virtue of my other senses telling me plainly that it's not there) is when I'm the caster. If I'm not, if the caster just tells me, "By the by, this 'fog cloud' is actually an illusion," I would expect to still have to make that Investigation check. I might try to talk the DM into giving me Advantage on it, since I've been told it's an illusion, but still.

[Voltage89]

I consider all this quibbling about wording pretty pointless. There is one simple way to determine if how it is being adjudicating is fair, and that is to swap your position with the player/DM.

For those arguing from the position of a player, that an NPC shooting an arrow at a wall would not reveal an illusion, flip the script, and place yourself (as a player) shooting an arrow at a wall conjured by a monster. If you are telling me that you would accept a DM saying "sorry, you can't tell if the arrow went through the wall or not, you still have to make an Investigation check" without calling bull****, I have my doubts. Likewise, if another player revealed an illusion in that manner, if you are saying you would accept a Dm saying "no, only that character is aware it is an illusion, you must still act under the impression it is a real wall", I am going to again be sceptical.

Regardless of your choice of ruling, as long as you would apply the rule the same way if it was used by a DM, as you would if it was used by a player, then in my opinion you are ruling fair. But if you are expecting DM's to jump through additional hoops you wouldn't accept as a player (or visa versa), then you aren't.

This is obviously aside from any metagaming issue - if the DM is metagaming and using his knowledge that it is an illusion to circumvent it by having NPC's make unexplainable decisions (like shooting at a wall in the first place), then that is obviously wrong.
As I an the one who started this thread, I am actually trying to look at it from both sides. You see, I am running a one shot where the players are climbing the tower of an illusionist and will attempt to fight him at the end. I am also going to be playing in a new campaign once I get back to school where I will be playing an illusion wizard. I'm gonna test out my rules in the one shot and see how the players thought they worked and then I will most likely make another post addressing what worked well and what did not.

[tieren]

Heres the one I have been thinking about:

party is lost in a pyramid, the exit is hidden behind an illusion of a wall, but a sandstorm blows up outside and a wind and sand are blowing through the wall into the pyramid.

The party walks closer and sees the sand coming through the apparent solid wall, and feel it hitting their faces, they know it is real sand and not illusionary sand.

Does the wall reveal itself, turning translucent with no action by the party? Does the party still need an investigation check to see through it? Does the party get advantage on the check because of the inconsistency?

[Segev]

Heres the one I have been thinking about:

party is lost in a pyramid, the exit is hidden behind an illusion of a wall, but a sandstorm blows up outside and a wind and sand are blowing through the wall into the pyramid.

The party walks closer and sees the sand coming through the apparent solid wall, and feel it hitting their faces, they know it is real sand and not illusionary sand.

Does the wall reveal itself, turning translucent with no action by the party? Does the party still need an investigation check to see through it? Does the party get advantage on the check because of the inconsistency?

Admittedly, this is subjective, but the way you described it, I suspect they'd need a Perception or even Investigation check to even notice there's a wall there. If sandstorm-level sands are blowing in through the (real) opening, the party will see sand blowing in thick enough that they wouldn't likely expect to see the opening through it.

Also, consider how you, as DM, would describe what this looks like. Would you say "sand is coming through the apparently solid wall?" That's coloring it pretty strongly. Here's how I'd probably describe what I am envisioning based on your outline of the situation:


The thick walls of the pyramid have a faint howling radiating from them. As you walk along, you hear the howling rise in pitch and volume ahead, and a hissing noise joins it. Eventually, you see sand blasting out of the wall ahead, forming piles and whipping into the chamber in a thick cloud, as if propelled by a powerful wind. If you draw near, the sand crunches beneath your feet around the periphery of the cloud. In the cloud itself, the sand bites against your skin, as if attempting to scour your bones clean of flesh.

How the players approached it would determine a lot, from here. If they stopped to question the wall's interaction with the sand - even to, for instance, ask if it looked like the wall was turning into or magically generating the sand - I'd give them the Investigation check.

[Voltage89]

Heres the one I have been thinking about:

party is lost in a pyramid, the exit is hidden behind an illusion of a wall, but a sandstorm blows up outside and a wind and sand are blowing through the wall into the pyramid.

The party walks closer and sees the sand coming through the apparent solid wall, and feel it hitting their faces, they know it is real sand and not illusionary sand.

Does the wall reveal itself, turning translucent with no action by the party? Does the party still need an investigation check to see through it? Does the party get advantage on the check because of the inconsistency?
Jeremy Crawford described what he would do in this type if situation on sage advice - illusions. He stated that he would first look at what the players are doing. Are they actively looking around the room for an exit of some sort, or are they arguing about who gets to keep the ring they just found. It depends on what the party is doing for how much the dm is going to give away.

[DrowPiratRobrts]

Ask yourself: why would an archer shoot a wall?

Being an illusionist means you have to think of things people won't try to interact with, if interraction reveal the trick

As long as they're under the spell's effect, the enemies beave as if it was real. So, why would an archer aim at a solid stone wall?

This is my rule of thumb as a DM, and what I try to point out as an illusion wizard myself in our current campaign. If I ever feel like the DM isn't respecting the fact that NPCs treat my illusions as if they're real (EVEN if they see me cast a spell), then I always question him on it and ask if the NPC would really do that. It helps make sure we're all in the fiction and not metagaming. Don't be afraid to ask your DM why the archer shot the wall, and if he/she can't give a good reason ask them to change what that NPC does. Most reasonable DMs would realize their mistake and just correct the action in the moment (as long as you don't wait a turn or two to bring it up).

[Tanarii]

Does the wall reveal itself, turning translucent with no action by the party? Does the party still need an investigation check to see through it? Does the party get advantage on the check because of the inconsistency?
This is an easy one for me:
- illusion is automatically revealed to be an illusion he party the moment they can percieve the sand blowing physically interacting with and passing through the wall.
- wall turning faint requires an action to make an intelligence (investigation) check against spell DC to discern the illusion.

This would also happen if it was an illusion of fog btw. Because the sand passes through the fog, which it normally wouldn't.

[CharonsHelper]

This is an easy one for me:
- illusion is automatically revealed to be an illusion he party the moment they can percieve the sand blowing physically interacting with and passing through the wall.
- wall turning faint requires an action to make an intelligence (investigation) check against spell DC to discern the illusion.

This would also happen if it was an illusion of fog btw. Because the sand passes through the fog, which it normally wouldn't.

And you are a GM who I would avoid running any illusions with.

[Segev]

This is an easy one for me:
- illusion is automatically revealed to be an illusion he party the moment they can percieve the sand blowing physically interacting with and passing through the wall.
- wall turning faint requires an action to make an intelligence (investigation) check against spell DC to discern the illusion.

This would also happen if it was an illusion of fog btw. Because the sand passes through the fog, which it normally wouldn't.


And you are a GM who I would avoid running any illusions with.

Same, though I have a clarifying question for Tanarii: When you say it's "revealed to be an illusion" by the sand blowing through, but that it doesn't go translucent without the Investigation check, do you mean that you don't view the translucence as a consequence of knowing it's an illusion?

I might be able to work with that, though - and this is just perhaps semantic - I would suggest you not tell the players, "It's an illusion," just because they see the sand fly through the wall. Just describe what they see, and if they suspect it's an illusion, they'll try that Investigation check.

My objections to your version of things were predicated on an assumption that interaction-revealing-illusion automatically makes it go translucent.

If I'm reading you right, now, though, that illusory wall could have all the arrows the party has fire straight through it, and the bad guys could be quite sure it's an illusion because of this, but still couldn't see through it without stopping to make an Investigation check. Is that right?

[Brightersidegam]

Same, though I have a clarifying question for Tanarii: When you say it's "revealed to be an illusion" by the sand blowing through, but that it doesn't go translucent without the Investigation check, do you mean that you don't view the translucence as a consequence of knowing it's an illusion?

I might be able to work with that, though - and this is just perhaps semantic - I would suggest you not tell the players, "It's an illusion," just because they see the sand fly through the wall. Just describe what they see, and if they suspect it's an illusion, they'll try that Investigation check.

My objections to your version of things were predicated on an assumption that interaction-revealing-illusion automatically makes it go translucent.

If I'm reading you right, now, though, that illusory wall could have all the arrows the party has fire straight through it, and the bad guys could be quite sure it's an illusion because of this, but still couldn't see through it without stopping to make an Investigation check. Is that right?

This, ultimately, was my second line of thought to my first post. Basically arrow goes through wall, shooter is pretty certain that wall is illusion, but has to investigate it to see through it. Admittedly, shooter could just ignore investigating it, and attempt to walk through the wall anyway (if that's his intent), but it's only the act of beating the DC with an investigation check can they actually see through the illusion.

It's like any of those optical illusions you see everywhere. I like the spinning dancer silhouette one where it spins in place and it looks like it's going right or left, and you can then "trick" yourself to see it go the other way. You know it's an illusion, but knowing that it's add-on illusion doesn't change the effect, it's only until you investigate that you see it go the other way. One could rule illusion spells are the same way, they know magic is effecting their mind, but it isn't until they spend the time to investigate and disbelieve can they actually see through it.

Anyway, I've said my piece. Again, talk to your DM/players folks, they might think differently, and coming to a sound conclusion or compromise is on both you and them

[BreaktheStatue]

I think the way some forum posts and optimization guides tend to describe illusion magic is a least partly responsible for quite a few of these PC/DM arguments. They almost always say something like:

"If you're really creative and smart and stuff, illusion magic can be totally game-breaking/derailing/godlike(!!!!)....but only if your DM isn't a total square." They might as well just say, "Hey, do you want to try to show the table you're smarter than the DM? Have I got the sub-class for you!"

(I'm not saying any, or even most people, who want to play illusionists are like this - but if I was a DM who read this, and a new-ish player said "Hey, I'm going to play an illusion wizard," I'd definitely be on guard - almost entirely because I'll be wondering if the player read a guide about how to build a game-breaking PC).

So then some of the players who read these guides probably get unrealistic expectations about what they think their DM will, or should, let them get away with ("You mean you're not letting me break your game?!?! The guide promised me that I could break the game!"), and the DMs who read them probably overreact because they see "illusion wizard" and they feel the need to set a firm red-line to prevent things from growing quickly out of control.

Most of the guides usually recommend you talk with your DM before you roll your illusion wizard, but I'd go even further than that: If you haven't played with your current group for at LEAST a year, I wouldn't even think about playing one, because unless you already have a good mutual understanding with your DM - not "Oh, we talked about this for five minutes, and he said it was cool," but "I have observed my DMs decision-making processes for long enough to guess what he'll say before he says it," then you're probably going to fight.

[DrowPiratRobrts]

Most of the guides usually recommend you talk with your DM before you roll your illusion wizard, but I'd go even further than that: If you haven't played with your current group for at LEAST a year, I wouldn't even think about playing one, because unless you already have a good mutual understanding with your DM - not "Oh, we talked about this for five minutes, and he said it was cool," but "I have observed my DMs decision-making processes for long enough to guess what he'll say before he says it," then you're probably going to fight.

Or you could just both be reasonable adults about the situations as they come up. But I get how that's a big ask for most players, or just people in general. Also that excludes all the kids that play D&D in middle/high school, so they could just be reasonable teenagers about the situation.

I agree that it's worth talking to your DM though. I just don't think it's necessary to have played together before if you talk about it on the front end and are willing to do some give/take as issues come up. But maybe I just have unreasonably good friends, I don't know...

[Tanarii]

And you are a GM who I would avoid running any illusions with.
Interetingly, my players LOVE my ruling on illusions, which I developed from discussions on these forums. It makes them very useful. They dont have to worry about an someone shooting an arrow at a wall and suddenly everyone can see through it. It still blocks vision.

Edit: SegevYes, anyone firing arrows at an illusion would become aware its not real. They just wouldn't be able to see through it without the investigation check.

[Segev]

Interetingly, my players LOVE my ruling on illusions, which I developed from discussions on these forums. It makes them very useful. They dont have to worry about an someone shooting an arrow at a wall and suddenly everyone can see through it. It still blocks vision.

Edit: SegevYes, anyone firing arrows at an illusion would become aware its not real. They just wouldn't be able to see through it without the investigation check.

Okay, THAT I could work with.

To explain where my problem with your version of it comes from, I work from the assumption that knowledge that the illusion is not real is all it takes to see through it. The Investigation check and the revelation-by-physical-interaction achieve the same thing: they make the character know it's not real. This knowledge is what makes it translucent.

You separate the two: the Investigation check makes it translucent; knowing it's not real doesn't do so on its own. I don't like it as much, aesthetically, as my take, but it doesn't nerf illusions. Heck, it strengthens them for some purposes: Now I can put up an illusory wall and fire my eldritch blast or whatever out of it all day, and until you take one or more actions (until you pass the investigation check), you can't see through it no matter how firmly you know it's an illusion.

[JoeJ]

This, ultimately, was my second line of thought to my first post. Basically arrow goes through wall, shooter is pretty certain that wall is illusion, but has to investigate it to see through it. Admittedly, shooter could just ignore investigating it, and attempt to walk through the wall anyway (if that's his intent), but it's only the act of beating the DC with an investigation check can they actually see through the illusion.

It's like any of those optical illusions you see everywhere. I like the spinning dancer silhouette one where it spins in place and it looks like it's going right or left, and you can then "trick" yourself to see it go the other way. You know it's an illusion, but knowing that it's add-on illusion doesn't change the effect, it's only until you investigate that you see it go the other way. One could rule illusion spells are the same way, they know magic is effecting their mind, but it isn't until they spend the time to investigate and disbelieve can they actually see through it.

Anyway, I've said my piece. Again, talk to your DM/players folks, they might think differently, and coming to a sound conclusion or compromise is on both you and them

I like this, although if somebody has already figured out that what they see has to be an illusion the intelligence (investigation) check should be a lot easier. Maybe even auto-succeed in some cases, although still requiring an action.

[Segev]

I like this, although if somebody has already figured out that what they see has to be an illusion the intelligence (investigation) check should be a lot easier. Maybe even auto-succeed in some cases, although still requiring an action.

I recommend not mixing the paradigms. Either have it be trivial to get any sort of "physical interaction" to tell you it's an illusion, up to and including hard-to-follow arrows or the wind blowing against an illusory hard stone wall, but require the Investigation check to be made at normal difficulty all the time to see through it anyway...OR have the Investigation check vary in difficulty by giving Advantage if they have solid reason to doubt the illusion's reality, or making it automatic if it's very clear they couldn't possibly not conclude that it's an illusion.

I prefer the latter way, but can work just fine with the former way. Mixing the two gets back into "why do we need the Investigation roll, again?" territory, as the "revelation is obvious" thing starts to make it just plain automatic.

Consider, too, that the Investigation check takes a deliberate action by the character. He does already need to be suspicious. So making it easier because he has reason to be suspicious is like saying, "Despite the fact you have to already be in water to swim, it's obviously easier to swim in water than not in water, so if you're in water when you try to swim, you get Advantage or even auto-success."

[BreaktheStatue]

Or you could just both be reasonable adults about the situations as they come up. But I get how that's a big ask for most players, or just people in general. Also that excludes all the kids that play D&D in middle/high school, so they could just be reasonable teenagers about the situation.

I agree that it's worth talking to your DM though. I just don't think it's necessary to have played together before if you talk about it on the front end and are willing to do some give/take as issues come up. But maybe I just have unreasonably good friends, I don't know...

Yeah, I guess this was personal for me, haha. I rolled a gnome illusion wizard with a new group, and made sure to talk with the DM beforehand to talk about what his expectations were. He said he'd accept a lot, as long as it was "reasonable."

First game session, I tried on about five separate times to use minor illusion ("I'm already small, so I'm going to hide inside a false rock/tree stump/barrel illusion and eavesdrop from a distance!") - and his response was to just go ("My guard could hypothetically touch your rock, and discern that it is an illusion, so it won't work"). His idea of "reasonable" is to basically not have illusion magic in his game. I quit the group soon after, because I sensed this was not going to go well.

So that's why I think it's smart to get a feel for a DM before playing an illusionist. He/she can tell you they're going to be "reasonable" all day long, but unless you have a sense of your DM's personal style - not what they tell you their style is, but how they tend to rule - you might be in a for bad time.

[Tanarii]

Okay, THAT I could work with.

To explain where my problem with your version of it comes from, I work from the assumption that knowledge that the illusion is not real is all it takes to see through it. The Investigation check and the revelation-by-physical-interaction achieve the same thing: they make the character know it's not real. This knowledge is what makes it translucent.

Balance wise, I completely agree that allowing physical interaction to make illusions see through without a check, especially at range and for everyone who sees the interaction, is problematic.

From that perspective, I don think it's unreasonable to rule that all physical Interactions that take an Action work as making an Investigation check. I just don't think there is any RAW or RAI basis for it.

For that matter, I think my interpretation that the physical interaction doesn't make it go faint is skiing on thin ice. But given that I interpret "physical interaction" so broadly ...

[Segev]

Balance wise, I completely agree that allowing physical interaction to make illusions see through without a check, especially at range and for everyone who sees the interaction, is problematic.

From that perspective, I don think it's unreasonable to rule that all physical Interactions that take an Action work as making an Investigation check. I just don't think there is any RAW or RAI basis for it.

For that matter, I think my interpretation that the physical interaction doesn't make it go faint is skiing on thin ice. But given that I interpret "physical interaction" so broadly ...

Yeah, I think the main reason we read the RAW differently is in what constitutes a "physical interaction" and how important the explanation of why it does the auto-revelation is.

I read the RAW, and understand it to be saying that it takes an Investigation check which is more difficult based on the spellcasting prowess of the caster (i.e. the quality of the illusion) to realize it's not real. Once that realization is made, the illusion becomes transparent. It then has an acknowledgement line that, if you reach out to touch the illusion and see your hand/poking stick/whatever go straight through it without resistance, that also allows you to realize it's an illusion, without needing to roll a separate Investigation check. Having realized it's an illusion, you now see through it. This comes with the caveat that, if the illusion would not logically have surprised you to see your hand/stick/whatever go through it, it only triggers the Investigation check (and then only if the attempted physical interaction was a deliberate action to test the illusion), because simply having your sword swing through flames, fog, or other insubstantial but visible items would not be sufficient to give away the game. Sticking your hand in a fire works (no heat/burning), though at that point you're showing faith that you're confident it's not an illusion anyway.

The way I believe you read the RAW, you dissociate the Investigation check from realizing that it's an illusion. The Investigation check, for whatever reason (I'm sure you have a sensible one in your mind), allows you to see through the illusion once you've made it. The physical interaction - regardless of how broadly you interpret it - only lets the player know it's an illusion. Honestly, I think you don't need to treat it that way to get the same result. If you just say, "You see the arrow fly through the wall," the player is likely to assume it's an illusory wall. Though you also indicate you'll tell them, "Having seen an arrow fly into that fog, you know the fog is an illusion." Whereas I'd just say, "You see the arrow fly into the fog and disappear in its mists." And then let the players assume what they will, unless I believed they were deliberately watching to see if the arrow didn't behave properly wrt the fog, or vice-versa, in which case I'd have them make the Investigation check.

[Tanarii]

The way I believe you read the RAW, you dissociate the Investigation check from realizing that it's an illusion. The Investigation check, for whatever reason (I'm sure you have a sensible one in your mind), allows you to see through the illusion once you've made it. The physical interaction - regardless of how broadly you interpret it - only lets the player know it's an illusion. Honestly, I think you don't need to treat it that way to get the same result. If you just say, "You see the arrow fly through the wall," the player is likely to assume it's an illusory wall. Though you also indicate you'll tell them, "Having seen an arrow fly into that fog, you know the fog is an illusion." Whereas I'd just say, "You see the arrow fly into the fog and disappear in its mists." And then let the players assume what they will, unless I believed they were deliberately watching to see if the arrow didn't behave properly wrt the fog, or vice-versa, in which case I'd have them make the Investigation check.
I rationalize my interpretation of the RAW abstraction into an in-universe explanation as follows:

Physical interaction allows any observing creature to immediately see, visually, that the illusion is not real. Even in the case of something like fog or darkness (assuming you actually allow the latter), it doesn't quite "act right" in reaction to any physical interaction. They now are aware it's an illusion. But awareness is not enough to see through it.

The Investigation check is a creature taking the time to impose their intellect over their senses, to overcome the power of the spell. Mere knowledge isn't enough to do that. It takes an act of intentionally imposing rationality.

[CharonsHelper]

Interetingly, my players LOVE my ruling on illusions, which I developed from discussions on these forums. It makes them very useful. They dont have to worry about an someone shooting an arrow at a wall and suddenly everyone can see through it. It still blocks vision.

Edit: SegevYes, anyone firing arrows at an illusion would become aware its not real. They just wouldn't be able to see through it without the investigation check.

I don't mean that you're doing it wrong/badwrongfun. But - it's not why I like playing with illusions.

It seems like it would make the occasional illusion useful from a tactical perspective, but an illusion focused character would not really be viable.

My favourite illusions to do are to split up the enemy with various walls/barriers so that my buddies can take them out in detail. That - and illusionary foes to keep most of the enemy busy. Neither of those would work well with your ruling.

[DrowPiratRobrts]

I rationalize my interpretation of the RAW abstraction into an in-universe explanation as follows:

Physical interaction allows any observing creature to immediately see, visually, that the illusion is not real. Even in the case of something like fog or darkness (assuming you actually allow the latter), it doesn't quite "act right" in reaction to any physical interaction. They now are aware it's an illusion. But awareness is not enough to see through it.

The Investigation check is a creature taking the time to impose their intellect over their senses, to overcome the power of the spell. Mere knowledge isn't enough to do that. It takes an act of intentionally imposing rationality.

I'm not trying to argue against your interpretation whole stock or anything, and I agree with it mostly I think. But allow me to point out that it seems like you're missing a line in the sand for what sort of "physical interaction" qualifies. If you leave it situational based on the illusion (i.e. wall vs fog) then you could determine when something interacts with the illusion in a different way than the real object.

If you say "any physical interaction" then you still need to define what you mean. Does a strong wind allow players to realize that both a wall and a fog are illusory, or just the fog since a wall shouldn't move with the wind? Does the physical interaction have to come from the players (or their actions, such as shooting an arrow)? If not, then by nature of being an illusion in the space-time universe, there is constant physical interaction with the illusion. The grass touching the bottom of the wall, branches lightly swaying in the fog, and on the far end of the spectrum the molecules in the air (I know that one is picking a tiny nit). But my point is, your ruling seems to demand a bit further explanation on what counts as "physical interaction." I'm sure you and your players know what this line is, but I'm genuinely interested.

[Tanarii]

I don't mean that you're doing it wrong/badwrongfun. But - it's not why I like playing with illusions.

It seems like it would make the occasional illusion useful from a tactical perspective, but an illusion focused character would not really be viable.

My favourite illusions to do are to split up the enemy with various walls/barriers so that my buddies can take them out in detail. That - and illusionary foes to keep most of the enemy busy. Neither of those would work well with your ruling.
Um ... that doesn't make an sense. My ruling makes it useful for such tactics. Just physically interacting with an illusion doesn't make it go faint. Therefore, even afte something interacts with it, illusions are still useful for things like splitting up the enemy with walls/barriers.

Given that most AL DMs I've played with rule that physical interaction makes it go faint, no check, I'm actually being pretty generous to the players.