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Death by Illusion...Part 2

Updated: Jan 6, 2020

"Then, methought, the air grew denser, perfumed from an unseen censer swung by seraphim whose foot-falls tinkled on the tufted floor..."



Since my original post, I've been doing sinful, murderous plotting. These things are good for the game!

As you may recall, my main issues with illusions have been where to draw the lines and how to rule on them. It's important to me that illusions (as a system) handle themselves: encouraging creativity while discouraging degenerative play. I also felt uncertain how to determine whether a Spectral Force is REALLY all that much better than a Phantasmal Force. The fly in the ointment stems from the fact that if you declare you are disbelieving, the saving throw is the same for either, right?

Uh, Anthony? Spectral Force allows the caster to MOVE and lasts 3 rounds after concentration ends. That's the definition of BETTER.

Yeah, I know, but doesn't it seem strange that adding sound, smell and thermal to the illusion doesn't actually matter when it comes time to disbelieve?

Well, Anthony, if the DM describes the fire as being hot and crackling and the smoke to be acrid and choking, then THAT'S a benefit. Because if the players ask whether the fire feels hot...

Yeah, but I'm going to interrupt here and I'll tell you why. First, players casting illusions on NPCs remains problematic. Second, whether you describe an illusion to a group of players this way or that, there are mechanical parts to this system that FEEL broken. The initial encounter with an illusion is going to catch the party by surprise. But after that, everyone is stating that they disbelieve everything all the time.

You know the player that does this:

SingedUtraEfficiencyGuy: "Hey, just to let you know, I'm going to be checking for traps every ten feet from now on."

Me: "Sorry, no. You'll have to interject EACH time you want to check for traps and tell me specifically what you are checking: like the floor would be one check. The right wall would be another, then the left, then the door, and so on."

SingedUtraEfficiencyGuy: "Are you serious?"

Me: "Am I ever not serious?"


Illusions have proved worse than checking for traps (since high-school if we're being honest) because it's not just the thief interrupting flow. The entire table becomes a snack-munching choir singing one refrain: "I disbelieve." It starts to sound like this.

At one point I considered allowing each character to disbelieve only once per X rounds but quickly abandoned the notion since, out of fairness, you must allow saves for each illusion assaulting the character; plus Players would quickly work out abuse stratagems: "Who's turn is it to disbelieve this round?"

On the flip side there's also part of me that thinks the illusionist got short shrift b/c it wasn't Gary's baby. It was Dave's. Pure speculation on my part. But is there anyone out there that played AD&D back in the day and, like me, will say that the class felt awkward, unfinished, muddy and difficult to arbitrate. So few spells! And yet, god how they bleed into one another!

How about this:

DM'sFirstEverIllusionistPlayer: "Uhm...I'm going to use Phantasmal Force to uhm...fireball the orcs."

Next Round...

DM'sFirstEverIllusionistPlayer: "Uhm...I'm going to use Improved Phantasmal Force to..fireball orcs."

Next Round...

DM'sFirstEverIllusionistPlayer: "Uhm...I'm going to use Spectral Force to fireball more orcs."

Next Round...

DM'sFirstEverIllusionistPlayer: "Uhm...gosh...I guess I'll use Shadow Magic to fireball orcs!"

(It's AD&D. The encounter contained 120 orcs!) But hey, let's ask some more questions:

  1. How do I determine fairly whether an NPC attempts to disbelieve a PC's illusion?

  2. Should I allow PCs of very high INT the possibility of also disbelieving (without declaration) in order to simulate the Ability Score? (IMO: of all the ability scores, INT is the one that's almost never simulated when it should be and sometimes simulated when it shouldn't).

  3. How do I quickly and efficiently rule on the various illusionist spells in the PHB and also bring abilities like Devil Illusions and Permanent Illusions into the fold?

Is it time to stop asking questions and just tell you what I'm doing? Here's my updated chart from my updated DM screen:

The chart breaks out monster INT categories according to MM2 p6 guidelines with a little bit of slush added by me. I use this for NPCs and monsters. Under special cases, I might also use it for PCs.

The way it works is that if a 1st level PC Illusionist creates a Phantasmal Force "Wall of Stone" to block a passageway, Monsters with 15 (Exceptional) INT have a 10% chance of noticing something funny and attempting to disbelieve. Against the same illusion, monsters with 18 INT have a 90% chance of stating that they disbelieve. You will note that with this chart, Improved Phantasmal Force is significantly better in this regard but that the chart doesn't change the text of the spell in the PHB. Those who state they disbelieve are granted a saving throw vs Spells (which is rolled by the DM). Success = the illusion does not exist for them. Failure = the Wall of Stone is real for them and they cannot resist the illusion even if they physically interact with it later on.

On the other hand, even monsters of 8 (Average) INT, who do not declare their disbelief upon seeing the wall, would get the same DM-rolled saving throw vs Spells if they TOUCHED the illusory wall or interacted with it in some way. Success causes the wall to vanish only for the disbelievers. Failure means the wall IS REAL for them.

If the Illusory wall is cast by an NPC the chart gives you the option to delineate between low-level illusions and high-level illusions: granting secret rolls to PCs of exceptional INT. When and if you do this is going to be a personal choice. At least you have the option.

So, we've covered my system for deciding when NPCs get saving throws vs PC illusions and vice versa. Now it's time tackle point 3: How do I quickly and efficiently rule on the various illusionist spells? What is my touchstone? My baseline?

The problem with #3 is that there are a lot of vectors. Is the illusionist concentrating? Did he make the illusion react to the fighter's sword swing? Given line of sight in this battle, the illusionist can see the cleric who is battling against the illusionist's Dragon Turtle, but the fighter is actually hidden from view, BEHIND the illusory Dragon Turtle. Therefore, the illusionist cannot see when the fighter hits it. Per the spell description, that is grounds for ending the spell. Also it's a muddy ugly thing to check in every battle. Checking LOS from caster to target is tricky enough in a complicated melee with interesting terrain.

PHB p75 Verbatim: "The illusion lasts until struck by an opponent-----unless the spell caster causes the illusion to react appropriately----or until the magic-user ceases concentration upon the spell (due to desire, moving, or successful attack which causes damage)...Creatures not observing the spell effect are immune until they view it."

I have to admit I think the wording is imprecise and yet it is the foundation upon which all other illusions are based. Of course the illusionist will TRY to react appropriately, right? It's clear that if the illusionist moves or is hit by an attack, the spell ends. But the last bit is not clear. If your eyes are closed at the start of the spell, you're golden, right? What about if you close your eyes AFTER having seen the illusion? The fact that I will get different answers from the audience in regards to this question only proves that it's muddy.

Phantasmal Force offers no one might think closing your eyes would make you immune. But with Spectral Force, closing your eyes does not alleviate the sound of claws on stone, or the hot breath of an illusory beast against your face.

On the one hand, we are talking about a level-one illusionist using Phantasmal Force (a third level M-U spell) to DEVASTATING effect presumably against 1st level monsters. The illusory Dragon Turtle bites for 4d8 dmg. And each claw deals 2d6! On the other we are saying that if you close your eyes, you make yourself mostly immune to the 29th level illusionist standing before you. This feels broken.

I'm not going to interpret the spell's area of effect verbatim either. I'm not going to say, "Sorry pal, you can create a very sharp 8-inch toy." Because based on the spell's text and explanatory notes in DMG, we know the AOE should perhaps be read as Eight 1"x1" squares + 1"x1" per level. I'm referencing PHB p75 & DMG p45 if you care. So I want to have very few limitations on what illusions can do. Yes, the young illusionist happens to have seen a real Dragon Turtle and a Fireball both (cf. DMG p45) so tadda! That grotto by the ocean with an ogre and his orc underlings are TOAST. We don't need a fighter b/c the orcs need a 17 to save vs Spells and the ogre needs a 16. Collect loot and level up.

I don't want to go in and change the text of the spells, or mess with their AOE etc. I just want them to be sanely balanced. Through the addition of new illusionist spells and through a few simple procedural rules, I believe I've done that.

Homebrew Disbelieving Rules

  • Saving throws vs Illusion are rolled secretly by the DM.

  • For each illusion encountered, a declaration of disbelief allows a SINGLE saving throw vs Spells. Success = that particular illusion ceases to exist for THAT character. A bonus of +4 is applied only if the character was informed of the illusion PRIOR to the roll.

  • Successfully attacking, touching or physically interacting with the illusion also triggers the SINGLE saving throw rule above. (eg. Prodding an illusory pit triggers the save. Being hit by an illusory fireball triggers the save. Climbing an illusory rope triggers the save, which must then fail in order for the climber to reach the top!)

  • Illusions that successfully deal damage are immediately thereafter dispelled unless stated; though intentionally trying to harm oneself on the illusion as a means of dispelling it will not do so.

I will spend the rest of this post interpreting these rules for you.

Let's start with something obvious that might even have happened in one of your games: return to the illusory stone wall, now cast by an evil illusionist that has thrown it up to block the PCs.

SingedUtraEfficiencyGuy: "Uhm...I'm back after checking for traps. Also I have an 18.50 STR and I disbelieved the illusion so I'll just pull Hank the Ranger through the illusory wall."

Hank: "Oh crap! I close my eyes."

Me: "Closing your eyes protects you only BEFORE you've witnessed the illusion. Hank has already failed his saving throw so for him the wall is ACTUALLY REAL and he believes himself to be merging on a cellular level with the granite or, put another way, that you are straining his tissue through a colander of solid rock. [rolls 6d6] Hank, you take 26 damage. On the upside, this experience also means that the wall ceases to exist because the illusion has dealt damage."

Hank: "Uh...I had 12 hp so I'm totally dead."

Me: "Ok. The rest of you who failed your saves witness UltraEfficiencyGuy drag Hank into the wall. Hank screams and dies but then the wall wavers and disappears. Congratulations. You can now continue down the hall."


The chart also gives you WIS adj for mental Saving Throws. A chicken with Animal INT cannot understand illusions and never needs to roll a saving throw. It will wander right through the illusory wall without noticing it. My basis for this is a Gygax comment I've lost my reference to, wherein he mentions that illusions fail to register with those of extreme-low INT. So the chicken gets off scot-free, meanwhile Thrud the Barbarian who has an INT of 3 must save vs Spells at a penalty of -3 to disbelieve.

Hey Anthony, what about the guy that keeps casting Fireball illusions?

In order to deviate as little as possible from spell descriptions and hew to the spirit of the system, I give the orcs a simple save vs Spells when the Fireball hits them. If they save, the Fireball deals no damage at all because they disbelieved. And of course, if they were wise, they'd get the WIS bonus to that saving throw as well. In the case of Monsters, for simplicity, I assume an INT rating of Genius ALSO applies to WIS and would therefore grant a Mindflayer a +3 or +4 to the save. Should the Flayer fail, however, the fireball IS real (but follows the spell's rules) and if cast by a 1st level Illusionist, would then deal 1d6 dmg. Furthermore the Mindflayer (or orcs) get a second save vs what they believe is now a real Fireball to determine if they take full or half dmg. Let's go further:

LeveledUpIllusionistPlayer: "I use Spectral Force to make it seem like the cup of wine the king has been drinking is poisoned."

Me: "The king is currently interacting with the cup so he automatically gets a save. [rolls d20] He fails and sniffs the cup. Then he seems to notice something off about it...the color...perhaps the taste. As a king, his mind immediately goes to a place that a peasant's mind would never go. Now he gets a save vs Poison. [rolls d20] He fails this as well and begins choking. Foaming at the mouth, eyes bulging, he dies moments later."

LeveledUpIllusionistPlayer: "I want it to be sleep poison."

Me: "I see. But the king is ignorant of poisons. Your illusion promoted a suspicion and paranoia in him. You dictated the nature of the illusion. But I get to decide how the king reacts to it. Therefore he died."

LeveledUpIllusionistPlayer: "But if I would have known that..."

Me: "This is the narrative I'm giving you based on your choices. You have for all intents and purposes poisoned the king. While I must consider alignment implications later, for now the castle guards are on you. They do not seem to understand how you did it, but since you are the only ones in the audience chamber, they assume you are to blame."


Before we go any further, it's time for the disclaimer. There are grognards. If they never took a hiatus from the game, they've been thinking about illusions longer than I have. So absolutely do it your way. But again, purpose of this blog is to help new players or those skeptical of returning to AD&D find their way, and help them adjudicate and balance the system.

By now, you probably understand the procedure I'm following.

  1. If PCs either interact with or express disbelief, they get a save.

  2. Only ONE save is ever allowed.

  3. If the illusion deals damage it is dispelled.

Therefore let's now extrapolate with creatures:

DM'sFirstEverIllusionistPlayer: "Uhm...I'm going to...use Phantasmal Force to uhm...make an ancient red dragon."

Me: "Ok."

DM'sFirstEverIllusionistPlayer: "I want it to breathe fire."

Me: "Ok. But you get eight 10'x10' squares + one 10' square per level. You're level 1 so you get 9 squares. The dragon occupies four of them. That means his breath weapon is going to be very short or very narrow."

[we declare other actions and roll initiative]

Me: "Right, so your illusion goes off on segment 1. The dragon appears suddenly in front of everyone, which is preposterous so the orcs save vs Spells at +4. [rolls dice] Four orcs disbelieve. The other 6 think the dragon is real."

DM'sFirstEverIllusionistPlayer: "Well, since it can't breathe very far can it just attack this round instead? I'll have the dragon whip the orcs with its tail?

Me: "Sure. Your side won initiative and you still have several segments to act so go ahead and attack with the Dragon." [bestows dragon THAC0 and Damage Dice on the Player...if the dragon had breathed on the fooled orcs, they would have saved vs Breath Weapon and then probably died...the Player rolls dice.] "You hit, roll damage." [the Player beams and rolls a bunch of dice] "Ok, those orcs are dead, but your illusion dealt damage so now it's dispelled."


Depending on the situation, I might rule that the Dragon's bite damage (at the beginning of the round) dispels the illusion and that the claw/claw portion of the routine (which would happen later) never gets to land. Or, under a surprise situation, I might allow all three dragon attacks to land before the illusion crumbles.

It is my opinion that illusions should not be allowed to continue dealing damage even if the illusionist maintains concentration. Once the pit is fallen into and causes damage (to those that fell simultaneously if appropriate) it then also disappears. If the pit is only trapping creatures (without dealing damage) then it may persist for as long as concentration is maintained--or slightly longer in the case of Spectral Force

This judgement on my part will certainly contradict the opinions of some, but I maintain that the rule is fair; scales logically toward Shadow Monsters and Shadow Magic; establishes sane boundaries/balance and encourages creativity. A one-shot serving of damage may now be less appealing than a cage that neutralizes a whole group of fighters with clubs.

Shadow Monsters and Shadow Magic are now a bit more logical...since these illusions can do damage even if they are disbelieved and, in the case of Shadow Monsters, can continue fighting and dealing damage round after round.

What then of Programmed Illusion and Permanent Illusion?

These are some of the highest level illusions available and as such I allow them to persist: a lava pool dealing damage round after round and a Horned Devil likewise able to attack over and over again. These are the only illusions with true persistence, IMO. But disbelief, of course, would still cancel them for the disbeliever----though his compatriots might go on burning or fighting indefinitely until they escape or leave the area.

When it comes to creature abilities (cf. Devils) to generate illusions, it is my personal opinion that such illusions are either of the permanent or programmed variety above per PHB p99. Such illusions would, however, likely vanish when the creature that created them is slain.

My recent delve into illusionists and illusions has prompted me to compile and in some cases create new spells. In the past I've often thought of illusions in a purely negative or harmful way. But now I'm considering illusory floors over real pits. If you make your saving throw against the illusion, you fall to your death. Illusory ropes, windows and so on offer more potential fun. Beneficial illusions that hold genuine threats at bay have the added devilish fun of becoming MORE difficult to avoid for higher level characters. And beneficial illusions that offer actual boons likewise become harder to take advantage of. I find this deviously exciting.

AdvancedIllusionPlayer: "I use Permanent Illusion to place gills on Presto, the Magician. If he fails his saving throw, will he be able to breathe under water from now on?"

Me: "Shit."

Because illusions are so powerful, I've settled on the notion that establishing an Achilles heel for illusionists is essential and undead (and other "mindless" monsters) help serve this critical role. As such, illusions that affect undead are not something you'll find in my game.

I hope this was useful and not just a rehash. I've been sinking a lot of thought into simplifying rules for illusions and trying to firm up how illusions can take care of themselves without resorting to a never-ending cascade of fiat rulings. Obviously you will want and need fiat sometimes (as in the case of Presto's gills) but you also want a reliable framework within which the majority of illusions can function without unbalancing the game.

As always, your thoughts are welcome.

Peace, Merry Christmas,

and happy gaming

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