D&D 5E Guidance on Illusion spells

[AaronOfBarbaria]

I was more just reacting to the OP. Typically I read "physical interaction" as simply attacking it. It's not like it could parry or use a shield or armor.

That seems like a fair enough adjudication, since it uses up at least part of an action to determine that the thing seen is actually an illusion.

But if I felt a need to assign an AC (maybe instead of a large image the illusion is a small agile pixie), the highest I would make the AC would be the same as the save DC for the caster.

That, however, I think isn't at all fair as it takes a roll that maybe the character isn't all that good at (such as because the player decided an 8 intelligence was plenty and doesn't have investigation proficiency) and replaces it a roll that is much more likely to succeed - effectively turning what would normally be a weakness of a particular sort of character (the dull-witted brute) into yet another strength.

Like I said...using a first level utility spell to negate an attack is pretty fair.

Not if it is definitely only 1 attack. Other 1st level spells that negate attacks usually have at least the potential of negating multiple attacks, if not multiple rounds of attacks.

But they also would quickly figure out their attacks are not effecting it and it isn't hurting them.

I think it is important to note the difference between thinking that what you are seeing - a completely silent, odorless, heatless beast that you can't seem to hurt and yet hasn't actually attacked you - is really there, despite being really strange, and thinking what you are seeing is an illusion.

At best, all the missing information (being able to see it, but not perceive it with any other senses) should be grounds for suspicion that leads to spending action(s) on making checks to determine that it is in fact an illusion. Not immediate proof that it definitely is an illusion, because in a world where magic is real there is no reason to assume that only one explanation is possible.

 

[dkmurphy]

Before I play a character who heavily rely's on illusions I speak to the DM FIRST and I ask them how they rule on them, what their opinions are on them etc etc. So that I have an idea of how they are going to rule. I give them some generic scenarios and ask they how they would rule. Some DM's I will NOT play an illusionist type character with because they essentially nerf them so its not worth it.

When casting one, and I see that the DM is trying to figure out how to adjudicate it, and I can tell they are thinking hard and are not sure how to handle it, I explain my intentions. I'll say, hey basically I'm trying to occupy these 3 goblins to take pressure off of the fighter for a round or two.... Then THEY know what you are actually trying to accomplish and if you are trying to get away with more than you should. Works well for both of us.

Also do some reading on interesting ways to use illusions. As others have said creating a creature to fight an enemy is not very effective. About the LEAST effective way to use it in my opinion. If you want to create something to fight an enemy summon something. Use the illusion for other things.

 

[Uller]

That seems like a fair enough adjudication, since it uses up at least part of an action to determine that the thing seen is actually an illusion.


That, however, I think isn't at all fair as it takes a roll that maybe the character isn't all that good at (such as because the player decided an 8 intelligence was plenty and doesn't have investigation proficiency) and replaces it a roll that is much more likely to succeed - effectively turning what would normally be a weakness of a particular sort of character (the dull-witted brute) into yet another strength.

Maybe Im not being clear or maybe I'm misunderstanding but you seem determined to argue with me.

You are contradicting yourself above so I don't understand what you are trying to say.

IMO illusions are very ad hoc and very broad in their applicability. So adjudication will vary based on circumstances. Negating an attack or two with a first level spell that has a lot of utility out of combat is sufficient. I think it is fair for the DM to rule that any attack reveals the illusion. I think if the nature of the illusion warrants the possibility of a miss the save DC is a fair AC. If the caster wishes to occupy a brute for more than one attack then the caster should not have chosen an image that plays to the brute's strengths and invites the brute to attack it. If you want the brute to take longer then the caster ought to choose an image that it will want to avoid and make it believable

Not if it is definitely only 1 attack. Other 1st level spells that negate attacks usually have at least the potential of negating multiple attacks, if not multiple rounds of attacks.

Then pick an illusion that enemies don't want to touch.

I think it is important to note the difference between thinking that what you are seeing - a completely silent, odorless, heatless beast that you can't seem to hurt and yet hasn't actually attacked you - is really there, despite being really strange, and thinking what you are seeing is an illusion.

At best, all the missing information (being able to see it, but not perceive it with any other senses) should be grounds for suspicion that leads to spending action(s) on making checks to determine that it is in fact an illusion. Not immediate proof that it definitely is an illusion, because in a world where magic is real there is no reason to assume that only one explanation is possible.

I never said they would figure out it is an illusion. I agree that even in a high magic world most NPCs and monsters would not have enough experience or knowledge to jump to that conclusion but I think if after a round or two they have not hurt it and it has not hurt them (I'm talking about illusions of hostile creatures here) then they are likely to just start avoiding the illusion. Even dumb monsters aren't going to just stand there indefinitely dancing around a silent image illusion.


Sent from my SCH-I535 using EN World mobile app

 

[jaelis]

The trick is to create an illusion of a specter or ghost, so that when their attacks pass through it, they still aren't sure if its an illusion or just incorporeal.

 

[Dorian_Grey]

This is, honestly, why I feel illusion spells should be removed from the game - and I love illusionists since I read about them in 2nd Edition. The problem, however, is that every illusion spell is very malleable, by design. Yet, I've only met one DM who was capable of working with an illusionist and not just nerfing them off the cuff because they wanted too. My own experiences generally indicate one of two "rationales" for DMs: 1) the NPCs are hard core rational actors who, in the middle of a fight, will sit down and work out the logic of the PCs ability to create something from nothing a big component of this is that "magical effects don't happen in the real world so if fire were to appear out of nothing, the NPCs would know it was illusion" which conveniently ignores that magic is part of this world, and fire appearing out of nothing is something that most NPC monster's will have seen their shamans do, the inverse logic is 2) the NPCs are all experts on spellcraft and thus know an illusion when they see one. This is why I generally don't play an illusionist or a spellcaster. I find most DMs want to know EXACTLY what a spell/action will do, and if something is poorly defined in terms of damage rolls or DCs, then the DM is going to take the least favorable to the PC interpretation. If this offends someone reading this, I'm sorry, but that's been my experience.

In general, this is what I would expect to see happen:

1. Illusionist casts their spell, and a unicorn appears. I'd have the player describe what they're doing: is the Unicorn just manifesting out of thin air or is it "coming" from behind a corner? If "manifesting" I'd give an arcana check at disadvantage to the NPCs to see if they put together that it might be an illusion with the DC dependent on the caster. I'd allow an NPC wizard of equal or higher level to the PC, with direct line of sight and ability to see material components, hear incantations, take a normal skill arcana check - though the PC wizard can attempt an opposed deception check to mask their actions.

2. The object now exists and the NPCs can begin to interact with it. The orc fires an arrow and rolls very high. They "know" that their shot was "perfect." I allow the PC wizard controlling the illusion to make a deception check to make it look like the illusion dodges the arrow. If they aren't paying close attention (i.e. threatened within 5' by an enemy) I would impose disadvantage. The DC is the attack roll. If the PC passes, no matter how good the shot, the NPC knows that they "missed." If the PC fails, I'd allow an illusion saving throw for the orc. This is because the NPC didn't PHYSICALLY interact with the illusion. The ARROW physically interacted with the illusion. Silent image is designed to fool sight, and sight is the only sense that the orc has used so far to interact with the illusion.

3. The other orcs, seeing this illusion and seeing the arrow fire and miss realize that they have a new threat, and act accordingly. When an orc decides to charge the illusion, the power of silent image is over as they will have physically interacted at that point. Per the description. Then the others can get a saving throw.

 

[Gadget]

I see what what some are saying with regard to attacks against Silent Image, I would be more sympathetic if this was only application of the spell, but creating a threatening decoy image in combat is certainly not the only way to apply the spell. Just the most straightforward and direct approach. I would argue that, depending on the image and the circumstances, having only one opponent waste an attack on the image might be a little meta-gamey on the part of the DM.

@Dorian_Grey, There is no need for all these arcana and deception checks, that's a very 3e way of doing things. It says right there in the spell that the opponents can take an action to make an Int investigation check to determine the image is an illusion. The key here is taking an action. This is all about action economy; you are forcing a monster to waste an action to determine it is an illusion by either making an investigation check or attacking the image. The spell also says that the caster can spend an action to make the image move (appearing to be walking, running etc.). This is also about action economy: if I want my image to appear to dodge the attack, and thus potentially have the monster waste another round's action on the image, I have to spend my action to accomplish this feat. It is still not clear to me that this is intended, what with 5e's cyclic initiative and actions, bonus actions, reactions and such. It would be a reasonable interpretation to rule that the image is completely stationary until my turn the next round and I spend an action to cause it to appear to move.

 

[AaronOfBarbaria]

Maybe Im not being clear or maybe I'm misunderstanding but you seem determined to argue with me.

You are contradicting yourself above so I don't understand what you are trying to say.

There is certainly some misunderstanding happening, because not only am I not contradicting myself, I'm not arguing with you.

My first point (starts "that seems like a fair enough adjudication...") is me agreeing that if a DM said that's how things worked, I'd accept that ruling.

The second is me commenting that I don't think changing the odds from whatever Intelligence (investigation) vs. spell save DC happens to be to whatever an attack roll vs. spell save DC happens to be would be fair because it removes one of the, already very rare by all power-gamer accounts I've heard, reasons not to dump your Intelligence score.

I also never said that you did say "they would figure out it is an illusion," I simply added to the conversation as a whole that everybody should be clear that there is a difference between what you did say (that there would be suspicion, to paraphrase) and knowing something is an illusion.

Sorry for the confusion.

I agree that even in a high magic world most NPCs and monsters would not have enough experience or knowledge to jump to that conclusion but I think if after a round or two they have not hurt it and it has not hurt them (I'm talking about illusions of hostile creatures here) then they are likely to just start avoiding the illusion. Even dumb monsters aren't going to just stand there indefinitely dancing around a silent image illusion.

To add even further clarity, I've quoted this portion of your post to state that I absolutely agree with it.

 

[jaelis]

I'll throw in that as I run illusions there are two different things that can happen. If a creature spends an action observing it and succeeds on the Int check, then the illusion fades and that creature can see through it. But if you just interact with the illusion and realize it is insubstantial, you can act on that fact as you like, but the illusion remains fully visible. This isn't quite what the spell description says, but it makes more sense to me.

 

[dkmurphy]

This is, honestly, why I feel illusion spells should be removed from the game - and I love illusionists since I read about them in 2nd Edition. The problem, however, is that every illusion spell is very malleable, by design. Yet, I've only met one DM who was capable of working with an illusionist and not just nerfing them off the cuff because they wanted too. My own experiences generally indicate one of two "rationales" for DMs: 1) the NPCs are hard core rational actors who, in the middle of a fight, will sit down and work out the logic of the PCs ability to create something from nothing a big component of this is that "magical effects don't happen in the real world so if fire were to appear out of nothing, the NPCs would know it was illusion" which conveniently ignores that magic is part of this world, and fire appearing out of nothing is something that most NPC monster's will have seen their shamans do, the inverse logic is 2) the NPCs are all experts on spellcraft and thus know an illusion when they see one. This is why I generally don't play an illusionist or a spellcaster. I find most DMs want to know EXACTLY what a spell/action will do, and if something is poorly defined in terms of damage rolls or DCs, then the DM is going to take the least favorable to the PC interpretation. If this offends someone reading this, I'm sorry, but that's been my experience.

In general, this is what I would expect to see happen:

1. Illusionist casts their spell, and a unicorn appears. I'd have the player describe what they're doing: is the Unicorn just manifesting out of thin air or is it "coming" from behind a corner? If "manifesting" I'd give an arcana check at disadvantage to the NPCs to see if they put together that it might be an illusion with the DC dependent on the caster. I'd allow an NPC wizard of equal or higher level to the PC, with direct line of sight and ability to see material components, hear incantations, take a normal skill arcana check - though the PC wizard can attempt an opposed deception check to mask their actions.

2. The object now exists and the NPCs can begin to interact with it. The orc fires an arrow and rolls very high. They "know" that their shot was "perfect." I allow the PC wizard controlling the illusion to make a deception check to make it look like the illusion dodges the arrow. If they aren't paying close attention (i.e. threatened within 5' by an enemy) I would impose disadvantage. The DC is the attack roll. If the PC passes, no matter how good the shot, the NPC knows that they "missed." If the PC fails, I'd allow an illusion saving throw for the orc. This is because the NPC didn't PHYSICALLY interact with the illusion. The ARROW physically interacted with the illusion. Silent image is designed to fool sight, and sight is the only sense that the orc has used so far to interact with the illusion.

3. The other orcs, seeing this illusion and seeing the arrow fire and miss realize that they have a new threat, and act accordingly. When an orc decides to charge the illusion, the power of silent image is over as they will have physically interacted at that point. Per the description. Then the others can get a saving throw.

This is exactly why I always speak to a new DM about illusions BEFORE using them. I also bring up PRE-GAME or POST GAME that an opponent has to spend an action to disbelieve it. Turn it around on the players, who know all about magic, at what point would a PC spend an action to dis-believe the illusion when there are so many other possible explanations.

You are right that many DM's nerf illusions, too much IMHO. However I have gotten a great deal of mileage out of simple conversations pre and post game. I won't argue with a ruling during a game. Most DM's are trying their best to make a fun game, they are only human and doing things on the fly. They may not remember the specific rules for a specific spell off the top of their head. Having pre and post game conversations makes this a little better. Also when a DM gets a feel for a well played illusionist, it can help them in several ways.

They get ideas to use for their monsters. They learn the spell rules a bit better. It is really easy to miss that whole 'spend and action to disbelieve.' Also by telling the DM what you are TRYING to do can really help them adjudicate it, and often it will be in your favor. I think of illusions as really minor Wish spells. If you try to abuse a wish the DM will try to twist it and you will get the short end of the stick. If you police yourself and don't get greedy, you often get much better results. So if the DM hears your description and what you are actually trying to accomplish, it makes his job easier and most DM's will reward that.

Also because I DM too, I hate rule arguments during the game, so when I play I save that for after and its amazing what being polite and having a conversation do. DM's appreciate NOT being interrupted and argued with mid game, that also helps. In doing that with several DM's I have gotten away with more than I thought I could and fun was had by all. I think the key is finding a baseline with a DM and if that baseline is such that illusions would be effectively nerfed, then play something else. It will save you much grief.

In the meantime try explaining your GOAL with an illusion, not just the description. If gives the DM something to base his ruling on. Most DM's are just trying to have fun, make it easier for them and you get more than you would expect.

Tips for illusions: If it is going to interact with creatures in combat, use as others have said spectral foes. Make a ghost rise from a fallen person. Make environmental effects, you can mimic fog for example. Search for illusions on the forum and write down good ideas. Don't do the same thing every time, that gets annoying from the DM perspective and is boring. Think of interesting things you can do to control and modify the area. Many spells can be nearly duplicated with illusions. And with 5e there are no opposition schools, so you can still throw some other things around. Its nice to be an illusionist with magic missile and fireball and summoning spells. Mix them around.

If you are DMing, ASK your player what they are really trying to accomplish. Look at the intelligence of a monster, and their culture etc. to see if there is a good reason for them to fall for or suspect an illusion. As a DM use illusions against the players and see how they react and it will give you a good idea of what a intelligent thinking enemy would do when confronted with them.

Like in many things communication is important. If you can make your DM's job easier you will likely get more satisfaction in the end. That said there are definitely DM's I would not bother taking any illusion spells with, they just can't or won't be fair. In that case I would get upset and the DM would get upset which is not fun so why bother playing if it is not fun? So I'll play something else.

 

[Uller]

There is certainly some misunderstanding happening, because not only am I not contradicting myself, I'm not arguing with you.

Okay. Sorry for the confusion. I asked because last time we "argued" about something (Stoneskin spell) you convinced me I was wrong so I wanted to make sure I understood.