D&D 5E Problems with Illusions

[Kobold Stew]

I want to think about illusions.

Illusion spells are tricksy, and are inevitably subject both to player creativity and DM judgement. My sense is that there is no agreement about how they work, and want to think about what are the legitimate uses of spells from this school. And this leads to problems.

I’m thinking specifically of Minor Illusion (cantrip), Silent Image (level 1), and Major Image (level 3), but there are implications for Hallucinatory Terrain (level 4), Programmed Illusion (level 6), Project Image (level 7). With each of these spells, the player defines some sort of image created. If the enemy interacts with it physically, it is revealed to be an illusion. If a creature discerns the illusion, it becomes possible to see through it (where it presumably no longer has an effect). Finally, an enemy can use an action to attempt to discern the illusion through an Intelligence (Investigation) check.

The first thing to note is how the three spells scale.
Minor: 5’ cube, affects either sight or sound. 1 minute, no concentration. Objects only.
Silent: 15’ cube, affects sight only. 10 minutes, concentration. Object or creature.
Major: 20’ cube, affects all senses but no damage. 10 minutes, concentration. Object or creature.
The variables therefore are size, senses affected, duration, and type of thing represented.

Specialist Illusionists gain the ability to amp up Minor Illusion (sight and sound, at level 2) and to change the nature of the illusion after it has been cast (for each of these three spells, at level 6). The upper level spells have specific uses, but are not for creative illusions in combat.

Tricksy elements. Let’s start with two basic uses in combat (I know there are lots of non-combat uses of illusions; I’m not thinking about them for now).

Cover. I am in a ranged combat and cast any of these spells to make a defensive barricade, no longer than 5’ wide and 5’ tall. Poof. Maybe I allow myself arrow slits, or a peekaboo window. Do I have 3/4 cover? I think I do, until someone interacts with it. That means they have -5 to hit me.

Problems:
* An enemy fires an arrow at me anyway. If they hit me, have they interacted with the illusion? No. If they miss me, have they interacted with it? Probably, but we don’t want any weirdness that interaction happens if you only interact if you come within 5 of the target number. Does any miss then count as interacting? Does the enemy have any chance to hit? Already things are subjective.
* Further, if the enemy does hit me (after -5), I make a concentration check if it’s a level 1 or 3 illusion, but not if it’s a cantrip. That also seems lame. Why would anyone use anything other than Minor Illusion to generate cover, except to make something 15’ or 20’ wide?
* What about choosing to disbelieve (make an Int (investigation) check). That uses an action, but (unlike attacking) has no ability to do me damage. It also can fail (and is more likely to do so, in most cases). I see no reason someone would choose to disbelieve.
* Maybe we need to bring in knowledge of spells. Does a successful Arcana check (not as an action) allow someone to know that there are no spells that could have brought this into existence except by being an illusion?
* Once one of the enemies has seen through the illusion, and they tell their friends, there is still no benefit for the friends, who must also somehow interact or disbelieve.
* What about my allies? They know I am an illusionist, and have seen my defensive barricade before. Can they see through it? Do they need to disbelieve? What if I have told them (maybe telepathically) that “I’m casting an illusion”?

None of this feels satisfactory to me. If it is fun (rule of awesome, etc.), it is only fun for the caster, and it would not be if an enemy caster did it to the party.

Distraction. So I’m in combat, and I see one enemy, a presumed spellcaster, hanging back. I cast an illusion of a brick wall in front of him, or a swarm of silent bees around his head. He knows or suspects it’s an illusion. Is my illusion (a 0- or 1-level spell) enough to shut him down for a turn, while he “interacts”? Is casting a fireball beyond where you can see (i.e. on me) interacting with an illusion at him? I don’t think so.

Problems.
* Is this a fair way to shut someone down for a full turn? Is it a more effective way to shut down a specific individual than color spray? Is there any way around this? Can a BBEG spellcaster consistently be occupied by a repeatedly cast cantrip? (which, given the players have multiple actions available to them, could be very powerful).
* Again, what about my allies? Can they get past the swarm of bees unaffected? Apparently. And do incoming arrows from my side create “interaction” to disempower the illusion for the enemy?

There are other issues.
Repeat castings. An enemy disbelieves the illusion. So I cast it again. As a DM, I’d give them at a minimum a bonus to save, but is this even right? What if it’s the same illusion, in the same place? This strategy could work both for both of the basic uses above.

Sensory input. Problematically, it doesn’t seem to matter what senses the illusion affects. As long as sight is affected, it can occupy someone. Silent bees are just as distracting as buzzing ones. This means that the level 2 illusionist ability doesn’t gain anything as a combat use.

Triggers. What prompts someone to investigate an illusion, in or out of combat? For players, an omission in the DM description may be enough, but what about NPCs? Noyhing the playrs do make it easier or harder to determine what happens next. Creativity is not rewarded.

Sounds. Can NPCs get distracted by noise? Does the sound of a lion or call for retreat or the opening chord of A Hard Day’s Night or the sound of someone shouting “Sneak Attack” actually impact things in combat? I think it doesn’t. Or it requires interaction, in which case…?

All of this just feels so sloppy. I don’t like casting these spells, because they require negotiation with the DM, and I don’t like it when players cast them when I DM for the same reason.

Are these problems inevitable? Are there ways to make illusions work smoothly? Why would someone want to be an illusionist?

Help. What do you do in your games to make illusions fun for all?

 

[mellored]

My general rule, fool me once.... (effectively 1/encounter).

Once a creature is fooled by one illusion, they start disbelieving anything out of the ordinary, and once disbelieved it's not effective. Creatures around them also disbelieve. Which is enough to let the player feel like they are doing something, but not auto-win things. I also modify his by an informal Int save, and the inginuity of the player. A clever idea will fool a stupid kobold a second time, but a litch won't be fooled by a simple trick.

Bees, for instance, would be distacting (advantage), until the start of the creatures turn. Then they would notice they are not being stung and ignore them. I also ruled that you need a program illusion (spell level 6), to make a bucket on someone's head, which stays with the creature within the 30' cube. And that minor illusion walls are just cover (+2 AC) to ranged attacks.


Though I did have a fun occasion where an illusionist made a fake fire, and then cast bonfire, which I had a half-orc stand just to prove it was fake.

 

[neogod22]

Here's the problem, sure you can get creative with illusions but, you can't create illusionary cover. At least not with low level spells. The spell does not actually stop anything, so it will just be concealment. Another thing is, you are concentrating on spells that are meant for only distracting effects, not spells that can actually do damage, which is fine of you're trying to distract. When you're low level, yeah these spells might be hard to use in combat, but as you get higher, they will be harder to disbelieve, unless of course you want to create something absurd, or you face something that doesn't care about what's in front of them (i.e. mindless creatures, undead). Really the trick to illusions is to create things that won't make the creatures want to question it. Like for example creating a cloud of fog.

Sent from my VS995 using Tapatalk

 

[ccs]

All of this just feels so sloppy. I don’t like casting these spells, because they require negotiation with the DM, and I don’t like it when players cast them when I DM for the same reason.

Are these problems inevitable? Are there ways to make illusions work smoothly? Why would someone want to be an illusionist?

Help. What do you do in your games to make illusions fun for all?

I bear in mind that I am NOT playing a boardgame, a miniatures wargame, or some computer game. Back & forths about things are an integral part of D&D. The DM must make judgment calls about things that happen during play. This is especially true when dealing with illusions & how PCs/NPCs react to them.

As a Player: I will cast my spell & tell the DM the effect I'm intending to achieve. And then I'll go with whatever ruling is decided upon.
As a DM I listen to what the player is aiming for & try and reach a fair result. Sometimes I already have an idea, other times the player (or even the whole table) takes a moment & discusses it. Sometimes the result will end up forming a standardized way of doing x. Other times it's just a ruling particular to this one instance.

In your ex of making cover: Well, you're presenting the foe a smaller target by hiding behind cover. So it stands to reason they're likely aiming high/wide. Afterall, if all I can see is your head & shoulders I probably won't be shooting at your abs or lower if I don't have a reason to think my shot could hit them....
If you're hit even after the negatives? Well, shot on target & you get tagged wherever is appropriate. No reason to disbelieve.
If you're missed? Then at my table we roll a die. Say a d6. 3+ the shot was too high/wide, no reason to disbelieve.
1-2 = the shot hit your "cover" & is seen passing right through. Now your foe realizes somethings up & sees through the illusion. If he tells his buddies? They can spend a round trying to disbelieve it or directly interact with it (like by shooting their own arrows through it!).

 

[jgsugden]

Things to remember:

* The DM's job is to make the heroes feel like heroes. Interpreting the illusions in ways that allow the PCs to be creative and effective is not a problem - it is giving them the great story they want to tell!

* People see the illusion whether they believe it is an illusion or not unless they successfully investigate it or physically interact with it.

* There are a lot of threads on illusions that go through all of the standard arguments. I suggest digging up some of them if you want to get the discussion you seek a bit faster than waiting for it to repeat here.

 

[Shiroiken]

General Rules
I allow Lore checks as Bonus Actions, so someone could try to determine the spell or effect. This doesn't dispel the illusion, but lets them know if they should interact with it or attempt to disbelieve.

Interacting with an illusion (except Phantasmal Force) is the best way to dispel it, but that's not always an option. The Investigation check is much more reasonable outside of combat, and I think the action part was put in to keep it from being too good in combat.

The more senses you can interact with the less likely they are to think to disbelieve. A swarm of silent bees is obviously an illusion, even if they can't see through it. Likewise a roaring fire without heat.

You can cast the same illusions over and over again, but they're not going to be very effective. If you were to do so, after the second, I'd probably allow the disbelieve check as a free action, just to keep it from being a way to block vision until the target's turn.

The best illusions are immobile, but hazardous. A growth of spiky thorns, an iron/stone wall, a roaring fire (with heat), etc, are all valuable, because they deter creatures from interacting with them. Copying spells that actually exist is a great plan, because intelligent creatures (the ones that are likely to make the check) are actually LESS likely to take the action. This usually only works once, but is great if you combo it with someone who has the actual spell (they interact with it, thinking it an illusion, but then take the effect instead).

Cover
Illusions can't grant cover, only the illusion of cover. Because I use the "if you miss by the cover penalty, you hit the cover" variant, it wouldn't grant any actual bonus. Most creatures, however, might assume you actually have the cover, and choose easier targets. While this helps the caster, it really doesn't help the group much.

Distractions
Remember, that illusions are automatically disbelieved once you interact with it. A swarm of bees around a caster would take no real movement to touch one. Even if the DM imposed that the illusion still blocked vision, they can still easily walk out of the area without penalty.

Sounds can cause distractions, but they require a level of believably. Using Minor Illusion to create an authoritarian voice that calls "halt!" against thieves in a city is going to be more useful than a lion's roar. I'd probably have at least one of the targets spend the action looking for the guards (the equivalent of making the check). Arguably, you could use auditory only illusions as Int saves (which is better IMO).

Illusions can be a lot of fun for those who think quickly on their feet. Sadly, I'm not one of them, so I only use them as a DM (where I have time to plan). As a rule, I suggest rewarding ingenuity, but punishing repetitive tricks.

 

[Imaculata]

One of the things that I tend to do as a DM when ruling on illusions, is that unless the players succeed on a disbelief check, the illusion behaves as one would expect the imaginary thing to do, if it were real. For example, what if there's an illusion of a solid wall? Don't I see my fellow players stepping through the thing? If I throw a rock at it, and yet fail my disbelieve check, doesn't the rock still pass through the illusion?

(Note: I play 3.5, so the specifics on disbelieve checks may differ slightly)

When I rule on these sorts of things, I tell my players that the illusion adapts to the situation. If another player steps through the illusion, the illusion makes it seem like he is still standing in front of the imaginary wall (even though he just stepped through, but thats not what the affected player saw happening). If you throw a rock at the imaginary wall, that counts as interacting with it. But if you then still fail your disbelief check, the rock seems to bounce off as you would expect when throwing a rock at a wall.

I tend to get pretty creative with the mind bending aspects of illusions. An imaginary pit may make you think that you saw your friends just fall to their deaths, or maybe they didn't walk across at all. Imaginary fire will cause things to catch fire... or at least, they will seem to catch fire. You'll feel the heat, and it will even hurt (but you might not take actual damage).

 

[Ralif Redhammer]

I’m not sure there’s any further quantification that can be done short of redoing the spells entirely with an intense amount of granularity (i.e., Create Small Illusory Monster, Create Large Illusory Object, etc.) that I don’t think most people would want in their game. I think there will always be a degree of subjectivity to illusions, and it’s probably a good idea to have a conversation with your DM if you plan on making use of them heavily.

For my part, I love it when players get creative, so I’m cool with illusions. But it’s also not a free pass to do anything, and is also dependent on the spell being used. Illusory wall of fire, sure, that’s fine. Giant red dragon appearing in the sky to breath fire on everyone, well, you better be using one of the higher level illusions. And someone with a greater knowledge of magic is more likely to recognize an illusion at work than Joe Goblin.

 

[jaelis]

Cover. I am in a ranged combat and cast any of these spells to make a defensive barricade, no longer than 5’ wide and 5’ tall. Poof. Maybe I allow myself arrow slits, or a peekaboo window. Do I have 3/4 cover? I think I do, until someone interacts with it. That means they have -5 to hit me.

I would not provide a cover bonus, since an arrow hitting the illusion would go right through it. But (a) the shooter might think you have cover, and thus not attack you, and (b) if you hide behind the illusion then attacks are at disadvantage since they can't see you.

Distraction. So I’m in combat, and I see one enemy, a presumed spellcaster, hanging back. I cast an illusion of a brick wall in front of him, or a swarm of silent bees around his head. He knows or suspects it’s an illusion. Is my illusion (a 0- or 1-level spell) enough to shut him down for a turn, while he “interacts”? Is casting a fireball beyond where you can see (i.e. on me) interacting with an illusion at him? I don’t think so.

I would count the bees as interacting right away, since you would be able to feel a real swarm. The wall could be explored with an "interact with an object" action. So this probably wouldn't shut the caster down.

 

[iserith]

I want to think about illusions.

...

All of this just feels so sloppy. I don’t like casting these spells, because they require negotiation with the DM, and I don’t like it when players cast them when I DM for the same reason.

Are these problems inevitable? Are there ways to make illusions work smoothly? Why would someone want to be an illusionist?

Help. What do you do in your games to make illusions fun for all?

I handle illusions the exact same way I handle every other thing a player describes his or her character as trying to do.

I get from them a goal and approach. I decide if their approach is sufficient to achieve their goal based on the situation and, if it's uncertain, I go to the dice.

As an example from my last session, the PCs were holding off wave after wave of enemies while the city was being assaulted by a large force of monsters. In particular, the PCs had to hold the line so that no monsters could move into position to outflank the wall defenders. The necromancer, some rounds before, had cast Evard's black tentacles to block off part of the street. Up-armored ankylosaurs with well-fortified howdahs on their backs full of goblin archers were making their way down the street to take out the barricade the PCs were defending.

The wizard/monk used a minor illusion to create the image of a big shiny apple amid the tentacles (approach) in a bid to lure one of the dinosaurs into the hazard (goal). I wasn't sure if ankylorsaurs ate apples, so I called for a DC 15 Intelligence check from the wizard/monk as a test of his ability to recall lore about animals. On a success, he would be right and would achieve his goal. On a fail, he would be wrong and would not. He passed and the ankylosaurus went straight for the apple and got tangled up in the tentacles. This saw the goblins all bailing out of the howdah and making a break for it which led to other fun stuff as some of the PCs hunted them down through buildings as they tried to nimbly get around the barricade and into the market while the other PCs focused on stopping the other dinosaurs.