D&D (2024) Illusion Magic in 2024

[Kobold Stew]

Sure you can. Illusions exist. If they didn't you wouldn't see them. But thanks for confirming there's not actually a rule in the books preventing the attacking of illusions - just some sophistry to bend the language to the results you want.

The ground doesn't have an AC or Hp either. You can attack it just as well.
Or better yet, since in your view the illusion doesn't exist, then there's nothing there to Study so you can't ever find out it's an illusion...

So I read your initial post, pre-edit, before you added the personal attack. I honestly thought your post was meant as a joke. It seems you are serious, though, and so let me ask:

What is the result that you think I want? And where do you think I have misread the PHB?

I may have follow-up questions to better understand your objection.

 

[FrogReaver]

So I read your initial post, pre-edit, before you added the personal attack. I honestly thought your post was meant as a joke. It seems you are serious, though, and so let me ask:

What is the result that you think I want?

In the OP you said:

What follows is my trying to make sense of the rules so that illusions remain effective but are not game-breaking. Thoughts welcome. I am trying to get playable rules that work.

tl/dr: Illusion magic rules are poorly written but are only meaningful if they are not trivially overcome. Attacking an illusion to make it fade from sight is trivial and by itself should not count as "physical interaction". The final section presents the guidelines I think are implied by the PHB, and are (I feel) balanced for players and NPCs.

I think this snippet of your OP fully answers your 'what is the result you think I want' question.

And where do you think I have misread the PHB?

I think the misreading was when you said the PHB rules say you cannot attack them and proceeded to use the premise that this would mean 'the Study guidelines are lousy' as your best evidence for that. See the quote below. I mean maybe the Study guidelines in the rules really are lousy? The hide rules definitely were again.

Sorry -- you can't Attack the illusion (as a game term) -- there's nothing there; it has no AC, no HP. It's always a swing and a miss. The problem is, if that action alone causes the illusion to fade away, then all Study guidleines are lousy.

 

[FrogReaver]

Here's my take.

The Boulder Problem
There's no good solution outside the PHB rules to the illusory boulder on a PC's space problem and it's much too powerful an effect to allow at the spell levels of the ability that can produce it. If the whole party can move (no hiding actually required) in an illusory boulder and fire ranged attacked from it (granting advantage since they aren't seen, and disadvantage to hit them since they aren't seen and is available until every enemy uses and succeeds on their own non-attack action independently to 'Study', then you've not balanced illusions, you've made them the most powerful and versatile spells for most of the game. *Note many spells also require you to see the target.

This is why IMO the physical interaction clause exists and reasoning of 'you can see things pass through it' are both in the PHB. It's to prevent things like the boulder trick above.

 

[FrogReaver]

I think illusions are mostly meant to be out of combat spells, and the really are fairly amazing for that part of the game.

 

[FrogReaver]

One thing I always loved about illusion spells was that when the DM sent a bit more at us than we could handle, with some intelligent play it could easily give him a plausible way out of the TPK and that's something most DM's usually will take.

 

[kigmatzomat]

I find the "boulder" rules in phb just fine. Did you shoot an arrow into a boulder? Yeah, it's an illusion. Did you watch your ranger's arrow fly through a boulder? Yeah, that's an illusion.

To me there are 2 holes:
1) Illusions of intangible objects : "did you see your archer's arrow fly through that ghost/shadow/fog cloud?" "Yeah, and?" There should be something other than Study available
2) illusions the caster can move to have "dodge" attacks. "Did you the archer's arrow miss the goblin?' "Yeah, it dodged, and?" Now you need some way to adjudicate "I have the illusion dodge!" "Nuh-uh, Conan swings his axe through it!" "Nuh-uh!" "Yeah-huh!"

I put some rules for those scenarios back here in post 23

 

[Kobold Stew]

In the OP you said:

To me that's an clear statement that you aren't coming at this to truly try and understand what the rules as written mean. And just so I'm clear, I think this snippet of your OP fully answers your 'what is the result you think I want' question.

Why would you assume that I wrote the tl/dr before the rest of the post? Perhaps there lies the confusion.

In the post, I present the reasoning that brings me to the conclusion that I summarized . Not something that I "want", but what the PHB says.

I think the misreading was when you said the PHB rules say you cannot attack them and proceeded to use the premise that this would mean 'the Study guidelines are lousy' as your best evidence for that. See the quote below. I mean maybe the Study guidelines in the rules really are lousy? The hide rules definitely were again.

There's a section in the OP called "Attacking an Illusion". Of course you can take your action to swing at an illusion if you choose to do so.

However, doing so is different from "interacting", which (it turns out) is a term with a definition, that normally takes an action. If we ignore that definition, and equate attacking with interacting, then the very prominent statement about rolling an Intelligence (Investigation) check is functionally meaningless, because it sets up a challenge that can be failed when tossing a copper piece or making a ranged attack would automatically succeed. That's not "evidence"; it is a conclusion, and one I am happy to discuss if you wish.

 

[kigmatzomat]

I think

However, doing so is different from "interacting", which (it turns out) is a term with a definition, that normally takes an action.

That's not quite correct. in the OP you say

The PHB tells us (p. 24):
Interacting with Things. You can interact with one object or feature of the environment for free, during either your move or action. For example, you could open a door during your move as you stride toward a foe.

Meaning "interaction" is a non-action that occurs as part of another action/move. So you could poke a suspected illusion on your turn for free, assuming it was stationary. And that its an illusion of an "object or feature of the environment". That rule wouldn't seem to apply to creatures so players wouldn't think to try.

So back to the other RAW, the wording in Minor Illusion is "...Physical interaction with the image reveals it to be an illusion, since things can pass through it."

Any physical weapon applied to an illusion would be "things pass(ing) through it." In melee, any stationary image larger than, say, a coin, should be an automatic task, not requiring an attack, even if the only things in your hands are weapons.

However, based on having seen people miss nails with hammers, making an attack roll and using the attack action seems reasonable for hitting very small objects.

Ranged interactions would require using an attack action as "throw things at another thing" is the definition of a ranged attack. It may not require a roll, as a stationary illusion of a goblin at 10ft is a gimme, but the same illusion 50ft away should require a roll, given that a lot of weapons are at long range/disadvantage.

the very prominent statement about rolling an Intelligence (Investigation) check is functionally meaningless, because it sets up a challenge that can be failed when tossing a copper piece or making a ranged attack would automatically succeed

That's not true. Physical interaction doesn't invalidate "study" as a use case, as there are times you don't want to walk up and poke something. "Are the Crown Jewels real? Guess I'll just go give'em a poke or throw stuff at them." Nope, doesn't sound good.

More common scenarios are hidden/invisible characters who don't want to risk being detected or where the suspected illusion is implausible to attack, perhaps behind a wall of force.

So rules on identifying illusions without any physical interaction are needed, even if other options exist.

But what the rules don't cover are animated illusions, like Major Image, where a caster can spend their action causing the illusion to act/react. How do you poke a suspected goblin illusion that jumps around wildly, staying at least 10ft away? Or it swings its axe wildly, but doesn't hit your shield or sword?

Or illusions of intangible things. You throw a coin at a Ghost and it passes through....how would that tell you it's an illusion? That would happen normally.

Those are gaps in the RAW

 

[FitzTheRuke]

I think and still think he was saying precisely what you say he wasn’t.

Well, then there's even less of a reason for your tone, because you were also wrong.

What Kobold meant is that if there are three ways to discern that something is an illusion: 1) Interacting with it (usually no action); 2) Attacking it (Action but no chance to fail) or 3) Studying it (Action, goid chance of failure).

... then 3) is usually a massive waste of effort. In the very least, your worst choice (though I appreciate the suggestion above that you might not want to damage the illusion, if it turns out to be a real, fragile, valuable thing).

The point of the issue, to try to find a balance between illusions being trivial and being scene-breaking, and finding a minor consensus on what that might look like

 

[FrogReaver]

Well, then there's even less of a reason for your tone, because you were also wrong.

I’m not the only one understanding him this way.

What Kobold meant is that if there are three ways to discern that something is an illusion: 1) Interacting with it (usually no action); 2) Attacking it (Action but no chance to fail) or 3) Studying it (Action, goid chance of failure).

... then 3) is usually a massive waste of effort. In the very least, your worst choice (though I appreciate the suggestion above that you might not want to damage the illusion, if it turns out to be a real, fragile, valuable thing).

The point of the issue, to try to find a balance between illusions being trivial and being scene-breaking, and finding a minor consensus on what that might look like

I’d prefer to have Kobold speak for himself. I do not trust your interpretation of his words.