D&D 5E Minor illusion

[FrogReaver]

You don't have to be hidden to get advantage on an attack. You only need to be unseen

 

[FrogReaver]

Notably, to be hidden, you have to be unheard and not clearly seen. It's not just about the visual aspect. So a Dexterity (Stealth) check might be appropriate to gain advantage from the attack behind the illusory wall if either of the required conditions are uncertain.

More broadly, I would examine the benefit through substantially equivalent actions such as a cantrip like true strike or the Help action. The benefit of minor illusion used in this way is that you can set it up a minute before hand, unlike either of the two aforementioned actions. I think the benefit should last no longer than a single attack, however, as with true strike or Help. It's not 100% clear that the physical interaction requirement reveals the illusion to any observers or just the person interacting with it, so I think it's fair to say once the arrow flies through the illusory wall, many creatures will know something's up and no further benefit may be gained.

That second paragraph is helpful. I'd never thought it wasn't clear that only the creature who did the physical interaction knew it for an illusion. That's exactly the kind of feedback I was looking for!

 

[Gadget]

I would be very careful with making the Minor Illusion cantrip into a stationary Invisibility spell. That would be too powerful for a cantrip. In fact, the way some describe it, it would like a stationary Improved Invisibility spell. Once someone sees arrows shooting from a solid stone wall, I would probably count that as 'interaction' and the game would be up. So, fine for an initial ambush (depending on the circumstances), but not a multi round advantage.

 

[Warpiglet]

I would be very careful with making the Minor Illusion cantrip into a stationary Invisibility spell. That would be to powerful for a cantrip. In fact, the way some describe it, it would like a stationary Improved Invisibility spell. Once someone sees arrows shooting from a solid stone wall, I would be probably count that as 'interaction' and the game would be up. So, fine for an initial ambush (depending on the circumstances), but not a multi round advantage.

I think this is sound reasoning. Not to mention interaction might be more broadly conceived. If I test the illusion, I can tell something is wrong. However, if someone else touches it or something else pierces it, suddenly I cannot see it for what it is?

It is reasonable to suggest you could use it for a round or two before someone knows its not what it is seems. Crafty use of spell still, and not game breaking.

As an aside, this was just on my mind as I have a warlock that I want to sneak around and this as well as misty visions were prime tools I hoped to employ.

Of note, I was scrambling to find a way to be sneaky since this only really affords the ability to hide. If I bang my greaves on the wall or clank around, it will invite investigation.

 

[Warpiglet]

I want to update my 2 coppers.

"physical interaction with the image reveals it to be an illusion."

It does not specify who is interacting and in fact it may be purposeful. As I read it now, things passing through it at all show it for what it is.

Secondly:

"if a creature uses its action to examine the sound or image" it can be shown to be a fake. That does not imply you must interact in any way with it since sound really is just sound (how can I interact with it?). Paying close attention without physical interaction thus also shows it to be a fraud if you make and intelligence checks.

With this more careful reading, I think seeing anyone/anything (including yourself another person or an object) pass through and interact with the image shows it for what it is.

Without witnessing an interaction, you can spend your round scrutinizing the thing and determining without interacting that it is phony. Many times you would not! If there is rubble and I add on the pile, someone would be likely to keep on walking especially if they looked behind the pile.

Still good for a round of hiding even shooting through it up to the point someone sees where the arrow came from...

 

[jgsugden]

It depends upon a few things under the RAW. When you cast the spell, everyone (but you) sees the object you created as if it were real. Once they discern that it is an illusion, they can see through it. But, how do you discern that it is an illusion?

1.) Physical interaction with it. If there is physical interaction, it is revealed to be an illusion. If it has been revealed to be an illusion, you've discerned it to be an illusion and can see through it. However, what does physical interaction involve? Note the sentence in the PHB does not require YOU to physically interact with the object - just that there be physical interaction with it. Once an arrow passes through the illusion, it is revealed to be an illusion and anyone that has seen the arrow pass through it can discern that it is an illusion. A DM might require a perception check to note the arrow passing through the illusion, but that is more of a factor of seeing the arrow than seeing the illusion.

2.) Without physically interacting with it, you might determine it is an illusion by spending an action to Investigate it. You'd do this if you had a reason to suspect it is an illusion, or had a reason independent of it being an illusion, but could not prove it to be an illusion with merely a touch. If someone stole a painting that was behind a wall of force, someone that suspects it was stolen might investigate it from behind the wall of force to see if it is an illusion - but someone also might not it is a fake illusion if they were just looking at the beautiful painting and not realizing it might be an illusion. If you see a rock suddenly appear, you might guess that it is an illusion. However, until you investigate it or there is physical interaction, you won't be able to see through it.

So, let's say that you cast an illusion of a rock and step into it to try to get a chance to get advantage on an attack. As you step into it, you physically interact with it. Anyone that could see you enter the rock would know it is an illusion. If they were on the opposite side of the 'rock' and could not see you enter it, they would still not be able to discern it is an illusion. Once you fire at them from in the rock, if they see the arrow leave the rock, they would know it to be an illusion and it would become faint to their eyes and they could see you. However, let's say that instead of hiding in the rock, you hide behind it. You do not reveal it to be an illusion when you step into it.

 

[FrogReaver]

If the PHB really does mean any physical interaction with the illusion reveals it for what it is then doesn't that mean as soon as you interact with the illusion whether the monsters can see you interacting with it or not that they will then also know its an illusion.

Basically what is being claimed the PHB allows for doesn't make sense unless everyone sees you physically interact with the illusion but that's not the only way for things to go down.

Thoughts?

 

[FrogReaver]

So, let's say that you cast an illusion of a rock and step into it to try to get a chance to get advantage on an attack. As you step into it, you physically interact with it. Anyone that could see you enter the rock would know it is an illusion. If they were on the opposite side of the 'rock' and could not see you enter it, they would still not be able to discern it is an illusion. Once you fire at them from in the rock, if they see the arrow leave the rock, they would know it to be an illusion and it would become faint to their eyes and they could see you. However, let's say that instead of hiding in the rock, you hide behind it. You do not reveal it to be an illusion when you step into it.

So, by the PHB why is this limited to just those that could see you when you entered the illusion?

 

[iserith]

If the PHB really does mean any physical interaction with the illusion reveals it for what it is then doesn't that mean as soon as you interact with the illusion whether the monsters can see you interacting with it or not that they will then also know its an illusion.

Basically what is being claimed the PHB allows for doesn't make sense unless everyone sees you physically interact with the illusion but that's not the only way for things to go down.

Thoughts?

I think it's circumstantial and the DM needs to make a judgment call as to whether Creature A's physical interaction with the illusion also reveals its illusory nature to Creature B and/or Creature C (and so on). The specific context of the scene should tell.