D&D (2024) Illusion Magic in 2024

[FrogReaver]

Because you quoted it.

That makes no sense. Such an assumption isn't necessary simply because of quoting.

I want rules that work at the table, yes. And, yes, I offered a proposal that cites the PHB. It's not a coincidence that the proposal follows from the passages cited.

A. The proposal doesn't follow from the passages, at best it's an interpretation trying to be forced upon the text.
B. If you want rules that work at the table then don't allow illusions to give advantage to allies + disadvantage to enemies for the whole combat unless every enemy gives up it's action to take the study action and succeeds. If you can find a simple way to do that without the study action then do that. Heck, share that and I probably will too. But it doesn't need to be forced into the existing rules. Houserules are okay.

Your interpretation, as you've explained it, does not explain the repeated emphasis in the spell descriptions.

Of course it does.
1. You can take a Study action to examine an illusion, make a check that if successful shows it to be an illusion
2. Also, any physical interaction will show it to be an illusion.
3. In the event you discern it's an illusion (no matter which method) then the illusion because faint.

The repeated emphasis exists because 1 and 2 are different ways of discerning something to be an illusion.

If this view is correct, then the spell descriptions state a way to counter illusions that has a substantial chance of failure, but there is an implicit way to counter illusions that will always succeed.

Yes. And it's been explained by others why that is the case. It's mostly to do with out of combat uses. Though I suppose one could create an illusory segment of wall and a single 5ft wide 10ft deep door way to create a chokepoint that your fighter stands in while ranged allies freely shoot whatever enemy stands in front of him. People aren't likely to attack such an illusion.

Essentially when a player decides to use illusions they need to find ones in combat that aren't going to typically be attacked.

Further, the experts in illusion magic (Wizards) never approach the ability to counter illusions that an Int 8 Champion Fighter of equal level possesses. And the DC associated with a given illusion is seldom if ever relevant. You may believe that is what is intended by the rules, but for me it points to an issue that warrants discussion.

Let's suppose that's an issue. So the PHB rules for something has issues. That's not surprising.

Wizards get Scorching Ray and can make more attacks than fighters at things. They get true sight. Detect Magic. Etc. They have lots of ways to deal with illusions. So I'm not even sure we can say the champion is better at it than him. He also is much better at detecting any illusions without direct physical interaction than the Champion.

I can think of many ways that illusion rules might be fixed at the table (and others in this thread have suggested some), and I know that I have played with my own house rules (not those here) the few times illusions have come up in games I've run. But for the most part, they don't come up, because the spells aren't used, and I think part of the reason is precisely the problem I'm trying to think through.

Maybe, I'd love to hear one that doesn't overpower them like everything I've heard suggested here so far.

 

[FrogReaver]

Here's the thing. If physical interaction from attacks doesn't reveal illusions then:

Turn 1. Players group up. Illusionist creates Illusion of a Boulder in their space. Enemies cannot see players. They get disadvantage to hit them and players get advantage to hit them for the same reason. Also, many spells fail to be able to be cast at the PC's.
Turn 2. Each enemy uses it's action to discern the illusion. I'll assume they all succeed.
Turn 3. Illusionist casts another illusion, this time of a stone structure in the players space.
Turn 4. Each enemy now needs to use it's action to discern this illusion. It's either that or accept that the advantage/disadvantage penalty.

Find a way around this kind of degenerate gameplay loop when you remove the physical interaction to end method and I think most would be happy with that solution.

*Note: for a single small creature or possibly medium this can be accomplished with a non-concentration cantrip for 1 minute.

 

[kigmatzomat]

Meaning "interaction" is a non-action that occurs as part of another action/move.

That's precisely not what the passage quoted says.

I am not sure how you get something different from

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.

It says during either your move or action you can interact with one object or feature of the environment for free. "Free" is not an action of its own, ergo, a non-action. But it must happen as part of a character's move/action.

Meaning "interaction" is a non-action that occurs as part of another action/move.

This is precisely the issue. Wall of Force is the edge-case I was thinking of (I didn't discuss it in the OP), in which case the Investigation roll sentence in the cantrip/first-level spell is to counter the specific case of a fifth-level spell. To me, this sounds improbable and does not reflect the way other spell descriptions are worded.

Wall of Force isn't countered, it still exists. It's not like Wall of Force prevents reading books or signs or reading lips. The "counter" is baked into the illusions.

All editions of d&d have been been less than ideal with illusions. 5e is at least consistent. Most sustained illusion spells have the same rules for physical interaction and study. Minor Illusion, Silent Image, Major Image, Programmed Illusion and Project Image all have them.

Hallucinatory Terrain & Seeming have Study, plus a variant of the physical interaction rules, because they cloak physical things, where things won't pass through entirely but can collide with the cloaked objects either "inside" the illusion or "outside" the illusion.

Phantasmal Force is a psychic-illusion that only has the Study but not physical interaction, but it also has an Int Save for the target to go along with the damage.

Then you get the big outliers of real-ish illusions.. Phantom Steed is an illusion except it's "quasi real" so you can physically ride on it. Mirage Arcane is also quasi-real, without actually saying it, as it can turn difficult terrain into non-difficult terrain and creatures with True Sight are aware it is an illusion but "the creature can still physically interact with the illusion." Illusory Dragon has the Study rule, but all it does is give Advantage to the Int save for half of the elemental breath weapon damage.