Can an illusion of being larger or smaller affect odds of being hit?

Question

Veil says

You can make the subjects appear to be anything you wish. The subjects look, feel, and smell just like the creatures the spell makes them resemble.

Let's say I make myself look like an ant. Assuming someone hasn't interacted and disbelieved yet, are there any penalties for attacking someone who looks so different?

What if I made myself look like a gargantuan dragon?

In the former case, it seems my foe might have a tough time figuring out where exactly to strike (and certainly couldn't benefit from precision). In the latter is seems that a foe would likely swing at a square I'm not in, at least at first.

Is there any Pathfinder rules text (or FAQs or whatnot) that suggests this could make one harder to hit? Or to explicitly state that it doesn't affect one's AC and/or provide a miss chance?

Answer 1

The spell veil, so far as I can tell, is present in Pathfinder absent developer commentary, either directly from a company representative or indirectly in a FAQ. The spell creates confusion on this topic and others that the game seems unwilling to address. Paizo messageboard threads 2012, 2013, 2014, 2015, and 2016, for instance, leave the nuts and bolts of the veil spell up to the GM.

Further, despite the veil spell having been taken straight from Pathfinder's antecedent dnd-3.5e (see here), the Giant in the Playground forums, for example, make little mention of the spell. (However, results are occluded by the far more popular discussion of the prestige class initiate of the Sevenfold Veil.) Even Skip Williams's 4-part Rules of the Game Web columns "All About Illusions" for that game only barely touches on glamers, reserving most of its text for the more popular figments.

In other words, like many spells of the illusion school, how the veil spell really works seems to be in the GM's hands. Just hope that the GM keeps in mind that the spell is typically a 6th-level spell that's, in essence, an advanced and really good, high-powered, multitarget, can-be-used-offensively version of the 1st-level spell disguise self.

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War story and house rules

Note: While the question didn't ask for house rules in case no official rules were available, I've seen the spell in play and had the opportunity to consider its long-terms effects. If uninterested in how this GM would rule, please, by all means, ignore this.

This GM has had in a dnd-3.5e campaign a player whose PC had access to the veil spell. The PC had access to the spell from levels 12 through 20 and employed the spell—I think—maybe three times. On the only occasion I remember that the spell was used to change the appearance of the PCs to creatures of a different size category, the PC disguised the party as beholders to lay the blame for a village's destruction at the approaching beholder army's metaphorical feet. The disguised PCs decimated the town… that was inhabited by low-level dudes who stood no chance of landing a blow and only an outside chance of detecting the ruse. The PC's player didn't press me on determining if the veil spell provided combat modifiers due to perceived size.

However, had the player pressed me for combat modifiers or the spell had seen more frequent use as a combat buff, this GM would've likely have the veil spell (and other similar spells) grant a size bonus to AC using a table like this:

               -----------PERCEIVED SIZE----------
ACTUAL SIZE  ||  F   D   T   S   M   L   H   G   C
Fine         || +0  +1  +2  +4  +8  +8  +8  +8  +8
Diminutive   || +1  +0  +1  +2  +4  +8  +8  +8  +8
Tiny         || +2  +1  +0  +1  +2  +4  +8  +8  +8
Small        || +4  +2  +1  +0  +1  +2  +4  +8  +8
Medium       || +8  +4  +2  +1  +0  +1  +2  +4  +8
Large        || +8  +8  +4  +2  +1  +0  +1  +2  +4
Huge         || +8  +8  +8  +4  +2  +1  +0  +1  +2
Gargantuan   || +8  +8  +8  +8  +4  +2  +1  +0  +1
Colossal     || +8  +8  +8  +8  +8  +4  +2  +1  +0

This table takes the absolute value of the difference between the creature's actual size and its perceived size and converts that difference into a size bonus to Armor Class (see here on Creature Size for how these numbers were attained). (While it's possible that a creature that's bigger on the outside—or smaller on the inside—instead should receive a miss chance, miss chances come with baggage that a simpler size bonus to AC avoids.) For example, a Medium human that uses the veil spell to take the appearance of a Gargantuan dragon receives a +4 size bonus to AC. This bonus would be ignored by foes that can see through the illusion, of course.

Answer 2

It does affect the odds of being hit

Because the target does not know your exact location if your illusory size changes. No, you won't gain any bonus to AC (though that is a good house rule), but a creature that fails their will saving throw cannot tell whether the illusion is real or not, so they treat it as real.

Veil is a glamer effect, very much like Invisibility:

Glamer: A glamer spell changes a subject’s sensory qualities, making it look, feel, taste, smell, or sound like something else, or even seem to disappear.

And these are exactly all sensory qualities affected by Veil (except for taste and sound):

The subjects look, feel, and smell just like the creatures the spell makes them resemble.

So if you create a veil of a dragon, you will look larger, will feel like a dragon ( the texture of skin, the sharpness of teeth, the temperature of your breath, etc), and will smell like a dragon. But you will not taste like one, nor sound like one (you might need to cast Ghost Sound for that).

On Invisibility, the effect is a visual glamer, it makes it appear as if you were not there, but in reality you are there. The reality is not changed by a glamer, only the perception of others about it.

The Ultimate Intrigue brings several clarifications about illusions (page 158), especially on the difference between the subschools of illusion:

Phantasms directly assail a creature’s mind, so the creature automatically and immediately receives a saving throw to disbelieve a phantasm. Figments and glamers, however, have the more difficult-to-adjudicate rule that creatures receive a saving throw to disbelieve only if they “interact” with the illusion.

[...]

For a glamer, interacting generally works the same as for a figment, except that the interaction must be limited to something the glamer affects. For instance, grabbing a creature’s ear would be an interaction for a human using disguise self to appear as an elf, but not for someone using a glamer to change his hair color. Similarly, visually studying someone would not grant a save against a glamer that purely changed her voice.

Those who interact with the subjects can attempt Will disbelief saves to see through the glamer, but Spell Resistance doesn’t help.

Personally, what I do those situations when GM'ing is to grab the statblock of that creature and use it as written, because those who believe the creature is real should treat it as real, including AC, saving throws, hit points, attack bonuses and damage dice. Unless, of course, a situation shows up where one of the non-illusory senses would allow a second will saving throw, like the half-orc biting the tail of our illusionary dragon ("I know the taste of dragons, and this is no dragon!").

Now, about the chances of being hit. If you create an illusory glamer of a larger-sized creature, the illusion will fill spaces (like 20 feet) that are not actually yours (say 5 feet). What happens when an enemy attacks one of those squares?

Well, we have to first ask: "They have saved against the illusion?"

• Yes: Then they realize they attacked something illusory and a translucent image of a dragon appears, releaving the target of our Veil.
• No: Then they believe they are fighting against a real creature, and if their attack did hit the dragon's AC, they believe they hit and probably damaged this dragon.

PS: If you open the bestiary on the dragon's page during gameplay, your players will surely believe the dragon is real, or you wouldn't be looking up the creature.

If the enemy attacked a square where they believe there is a dragon, but found your character (hidden through the veil), then it should be treated no different than the full concealment granted by Invisibility. Afterall, they did not know you were there and attacked the space where your character is located, even if they believe they were attacking a dragon. And this certainly should allow a second saving throw, as the feel of whatever was hit is different from one creature (a dragon's leg) to another (a human in a dress), but I can tell you this likely will depend on your GM.

If the caster casts the veil of a smaller creature, then all those who do not interact or fail their saving throws should believe they are looking at a smaller creature, be it an ant or a dog. Those who interact will be allowed saves if the glamer does not affect one of those senses like a dog talking instead of barking. If the veil creates the illusion of an ant, well, you just used up a 6th level slot to duplicate the effects of a 2nd level spell. By that level, the caster already has access to several spells that creature semi-real illusions.

As such, the veil of an ant would grant the target 50% concealment, if the attacker actually knows which square to attack (requiring Perception checks), just like if the target was invisible.