(3.5) Stacking Miss chances

[koeldflare]

Like the title implies, I'm wondering how certain spells that grant miss chances work with one another. Specifically I'm looking into the stacking effects of Displacement, Ghostform and Greater Mirror Image.

As a side note: is there any other spells that would stack with this combination? My character won't have a high AC so I'm looking into getting as many miss chances as possible.

[Curmudgeon]

(Greater) Mirror Image provides illusory doubles, but they go poof when struck. No other magical miss chances affect these doubles. Roll randomly to see whether a double or your person is targeted. Ghostform and Displacement stack on your person, though. Apply each miss chance sequentially.

[Ravens_cry]

I think Blur does, at least with Mirror Image, as it's purely a visual effect. By stack, I mean your doubles also have a 20% miss chance, even if targeted.

[koeldflare]

What I mean by stacking miss chances is having many effects that give miss chances, that someone who (if they were to attack me), they would have to roll miss chance after miss chance, hopefully ensuring me an eventual miss.

[PairO'Dice Lost]

What I mean by stacking miss chances is having many effects that give miss chances, that someone who (if they were to attack me), they would have to roll miss chance after miss chance, hopefully ensuring me an eventual miss.

Yes, they all apply; there's no "concealment bonus" or other reason the stacking rules would disallow it. You can either roll all of them sequentially or compute a single probability to make it faster, as long as you do the calculations right, but either way the percentages stack purely mathematically.

[Irreverent Fool]

I think Blur does, at least with Mirror Image, as it's purely a visual effect. By stack, I mean your doubles also have a 20% miss chance, even if targeted.

This is incorrect. Blur affects creatures only. The illusions created by mirror image are not creatures but may be attacked as such. Curmudgeon has it right, as usual.

This is a common conception among players for the reason you stated. "It's purely visual". Granted, if you follow that route, displacement applies too. However, mirror image at no point says that the visual effects of spells on you has any effect on chance to hit the illusions with the exception of spells that render you invisible to the attacker.

But to answer the original question: Yes. Each miss chance is rolled separately. Mirror images just get checked first and if an image is targeted, it doesn't get any of your buffs.

obnoxious
sig

[Random832]

Note that multiple miss chances are mathematically equivalent to a single miss chance equal to 1-∏(1-x), i.e. take the inverse of each miss chance [80 for 20, 70 for 30], multiply them all together [as percentages, i.e. 80%×70% = 56%, not 5600], and then take the inverse of the result [56% becomes 44%]

[Keshay]

This is incorrect. Blur affects creatures only. The illusions created by mirror image are not creatures but may be attacked as such. Curmudgeon has it right, as usual.

This is a common conception among players for the reason you stated. "It's purely visual". Granted, if you follow that route, displacement applies too. However, mirror image at no point says that the visual effects of spells on you has any effect on chance to hit the illusions with the exception of spells that render you invisible to the attacker.

But to answer the original question: Yes. Each miss chance is rolled separately. Mirror images just get checked first and if an image is targeted, it doesn't get any of your buffs.

I think you're missing the point here, Blur or any other illusion would not be effecting the Mirror Images but the caster himself. Mirror Image states that:

"Enemies attempting to attack you or cast spells at you must select from among indistinguishable targets."

Meaning that the doubles look exactly like you. There is no caveat that if your appearance changes during the duration of Mirror Image that the doubless appearances do not change, they are always identical to the casters current appearance.

Blur's description states:

"The subject’s outline appears blurred, shifting and wavering. This distortion grants the subject concealment (20% miss chance)."

It specifically states that the visual distortion causes the miss chance. Since Mirror Image makes the doubles indistinguishable from the caster, this means the doubles also all have the save blurred outline, and therefore a miss chance. Otherwise, you'd just have the enemies targeting the blurry one, which would be contrary to the explicit description of Mirror Image that states the caster is indistinguishable from the doubles.

If, however, the miss chance was due to the character being partly incorporeal, then the Mirror Images would not get a miss%, due to the effect not being due to a visual effect. In this respect the distinction between Blur being a visual effect is a relevant factor in granting miss%.

[ericgrau]

The problem with stacking most of these spells is that by the time you finish casting them the combat is over. I'd peg yourself with a greater invisibility and be done with it.

[Myrmex]

(Greater) Mirror Image provides illusory doubles, but they go poof when struck. No other magical miss chances affect these doubles. Roll randomly to see whether a double or your person is targeted. Ghostform and Displacement stack on your person, though. Apply each miss chance sequentially.

Wouldn't some sort of obscuring affect, like fog, affect them? They are, after all, targets with AC.

[Random832]

The problem with stacking most of these spells is that by the time you finish casting them the combat is over. I'd peg yourself with a greater invisibility and be done with it.

The idea for most of these exercises is that they're mostly relevant when you're powerful enough to be able to do all of these before combat or in the first round

[PhoenixRivers]

Greater Blink is probably one of the most useful spells for this. Add in Mirror Image, and you'll have a rather potent defense...

Because in this instance, the Mirror images blink too.

Mirror image is <Personal>, with a target of You. That means wherever you are, so to is the effect.

Greater Blink sends you to the ethereal plane, and, when you're there, the Mirror images are too.

So, in effect, people can miss your mirror images.

[ericgrau]

I think there was a FAQ entry on mirror image and blur. IIRC since blur is a visual effect it affects the images as well. EDIT: Yeup. Displacement works too, for the same reason.

[Myrmex]

Greater Blink is probably one of the most useful spells for this. Add in Mirror Image, and you'll have a rather potent defense...

Because in this instance, the Mirror images blink too.

Mirror image is <Personal>, with a target of You. That means wherever you are, so to is the effect.

Greater Blink sends you to the ethereal plane, and, when you're there, the Mirror images are too.

So, in effect, people can miss your mirror images.

It's actually Personal; see text. It seems that once the spell is cast, they are no longer a personal spell on you, as they can be up to 5 from at least one other image.

[Tyndmyr]

I've used blink + mirror image. We ended up ruling that it works on the mirrors, since they follow you, and you are blinking to the ethereal plane. They don't get the advantages of buffs on you, but they do get bonuses conferred by visibility/location.

[Person_Man]

I'm aware that it's a house rule, but when I DM I only allow the highest miss chance to apply. My reasoning is that other similar magical effects don't stack (named bonuses, Enlarge Person and Expansion, etc) and, more importantly, full casters (the most powerful group) tend to abuse it the most.

Koeldflare, I personally know nothing about your DM or your gaming group, but I would suggest that you be mindful about making yourself nearly impossible to be hit unless you happen to be fighting the final BBEG of your campaign. Like other RAW but potentially game breaking rules (touch attacks, Greater Invisibility, Polymorph, etc) it's best to use them rarely, if at all.

[Reaper_Monkey]

This is why Area of Effects were invented, I hope your stacking reflex saves too

[Fluffles]

This is why Area of Effects were invented, I hope your stacking reflex saves too

Nah, I've got evasion for that

[Reaper_Monkey]

Nah, I've got evasion for that

Touché. Very well... this calls for the age old crushing room! Nothing can evade a ceiling !

[Fluffles]

I can. I'm a ghost

[Curmudgeon]

Blur's description states:

"The subject’s outline appears blurred, shifting and wavering. This distortion grants the subject concealment (20% miss chance)."

It specifically states that the visual distortion causes the miss chance. Since Mirror Image makes the doubles indistinguishable from the caster, this means the doubles also all have the save blurred outline, and therefore a miss chance.

Blur
Illusion (Glamer)
...
Target: Creature touched

Yes, the Mirror Images are blurry, too, because that spell's description requires it. But that doesn't give the images a miss chance, because those images are not creatures. Blur only gives a creature a miss chance. Anything else would be exceeding the written rules.

If you need more than the RAW to work with, try this. Blurry Mirror Images aren't any harder to make some sort of weapon contact with, and that's all that's necessary to make them go poof. Blur make it harder to land a solid blow on an actual creature, where it could glance off armor or be dodged -- neither of which could happen with a Mirror Image.

The figments mimic your actions, pretending to cast spells when you cast a spell, drink potions when you drink a potion, levitate when you levitate, and so on.
...
Figments seem to react normally to area spells (such as looking like they’re burned or dead after being hit by a fireball).

These figments have no capacity to try to dodge weapon blows.

[Eldariel]

Touché. Very well... this calls for the age old crushing room! Nothing can evade a ceiling !

I block the ground!

[Keshay]

Yes, the Mirror Images are blurry, too, because that spell's description requires it. But that doesn't give the images a miss chance, because those images are not creatures. Blur only gives a creature a miss chance. Anything else would be exceeding the written rules.

If you need more than the RAW to work with, try this. Blurry Mirror Images aren't any harder to make some sort of weapon contact with, and that's all that's necessary to make them go poof. Blur make it harder to land a solid blow on an actual creature, where it could glance off armor or be dodged -- neither of which could happen with a Mirror Image. These figments have no capacity to try to dodge weapon blows.

Ignoring the relevant portion of an argument does nothing to refute it. It is specifically stated that the visual distortion generated by Blur is what grants the miss chance. It is specifically stated that the Mirror Images can not be differentiated from the caster by vision or hearing, therefore the images get a miss chance since the purely visual effect of Blur must be reflected in the appearance of the doubles in order for the spell description to be accurate. It does not matter that the Blur does not target the doubles, in this case the miss chance would be an effect of Mirror Image, not Blur.

Your argument is akin to saying that a Mirror Image would not reflect any changes made to the caster's appearance due to the casting of Alter Self, which certainly is not a reasonable argument.

And yes, blurry mirror images are harder to make weapon contact with, Blur states that the miss chance is granted by the visual distortion, which is then translated to the doubles. Neither spell mentions active attempts to dodge or Armor Class as being a constituent portion of the miss chance, so the abiltiy to dodge weapon blows is totally irrelevant to the discussion.

[Natael]

What are some of the best ways to get some miss chances loaded up onto a melee character via (non-custom) magic items?

[Glimbur]

What are some of the best ways to get some miss chances loaded up onto a melee character via (non-custom) magic items?

Minor Cloak of Displacement is like Blur all day, and arguably better than the Greater Cloak of Displacement because the greater one needs activation. It's core.

[Keshay]

Potions of Blur and Displacement will work too. If you have UMD or a friendly caster, a Wand of Greater Invisibility will do wonders for you.

[Sinfire Titan]

Touché. Very well... this calls for the age old crushing room! Nothing can evade a ceiling !

Ha! There's so many counters to that trap that you may as well throw plush dolls at a brick wall.

[Curmudgeon]

And yes, blurry mirror images are harder to make weapon contact with, Blur states that the miss chance is granted by the visual distortion, which is then translated to the doubles.

I won't try to refute your argument on the basis of the logic of different visual effects, because that isn't relevant here. The point that matters is that Blur only provides a miss chance to a creature, not a figment. The visual effect, a factor of Mirror Image, isn't pertinent to the restriction in the Blur spell's target. You can't get a miss chance from Blur for an invalid target, and Mirror Image doesn't provide a 1/n miss chance and an additional visual effect miss chance, because that's not afforded by the rules.

You can describe the visual effects any way you like. The miss chances do not stack if you obey the limits on each spell's capabilities.

[Paulus]

I won't try to refute your argument on the basis of the logic of different visual effects, because that isn't relevant here. The point that matters is that Blur only provides a miss chance to a creature, not a figment. The visual effect, a factor of Mirror Image, isn't pertinent to the restriction in the Blur spell's target. You can't get a miss chance from Blur for an invalid target, and Mirror Image doesn't provide a 1/n miss chance and an additional visual effect miss chance, because that's not afforded by the rules.

You can describe the visual effects any way you like. The miss chances do not stack if you obey the limits on each spell's capabilities.

This is quite literally one of the oddest arguments I've seen.

Basically you are both right. Blur works because it blurs the character. Mirror image works because it creates duplicates of the original which look exactly alike. So if the individual used mirror image and blur, ... logically the original would be blurred and the mirror images would be too, since it would be illogical for the mirror images not to blur because then it would be pointless to be mirror images. Therefore, they should work together.

On the other hand, mirror images blurred or not, when struck by a weapon will disappear and no amount of blurring them should make a difference because they can be just as easily hit. Because it was intended as such that mirror image only allowed you to have doubles that dissipated when hit, which makes the miss chance, removing a copy each time- that is, auto hit them instead of hitting you- to make the spell at least fair on SOME level. After all, if the images can be missed to, most foes would stand even less of a chance. Therefore, it must work illogically in the name of balance. Or so it is intended, and is written.

Therefore, The images do indeed blur along with the original thereby not distinguishing the original from the copies, yet the rules say blur only works on a creature and will not work on a figment. Thus it only works on you but it LOOKS like it works on the mirror images, but they receive no miss chance because it was not intended as such and therefore the spell remains balanced. Therefore when a create strikes at you and misses purely by the greater miss chance with the stacking chances of blur and mirror image, a mirror image dissipates because that is what makes it a miss. They hit one of them instead of you, regardless if the blur helped or not. You still loose a mirror image, are still blurred, so the miss chances and visualizations stack but the mechanics remain the same, thus it is not a total stacking but one that still works together. Thus, you are BOTH correct, yet on different sides. This works and that works. As written as intended.

[Keshay]

I won't try to refute your argument on the basis of the logic of different visual effects, because that isn't relevant here. The point that matters is that Blur only provides a miss chance to a creature, not a figment. The visual effect, a factor of Mirror Image, isn't pertinent to the restriction in the Blur spell's target. You can't get a miss chance from Blur for an invalid target, and Mirror Image doesn't provide a 1/n miss chance and an additional visual effect miss chance, because that's not afforded by the rules.

You can describe the visual effects any way you like. The miss chances do not stack if you obey the limits on each spell's capabilities.

I respect your strict interpretation of the rules as written, but as usual find the RAW to be incomplete and inadequate to describe all circumstances that may arise. In these cases a logical conclusion is acceptable to me and those I have played with. I agree to disagree.

/edit: AHHA! I see now. We have it backwards. You all are thinking that the miss chance is done first, that monsters always try to attack just the actual target, and that the images are an ablative kind of shield to be gotten through... That's not the case. An enemy has to choose which image to attack, hit its AC, then overcome the miss chance. Not, try to attack the PC, overcome the miss%, overcome AC, then overcome the MI.

Miss% is applied after AC, not the other way around.