[3.5] Stacking miss chances.

[unre9istered]

Just noticed this in the rules compendium for Incorporeal:

If a creature receives miss chances from multiple sources, such as from being incorporeal and having concealment, they don’t stack. Only the highest miss chance applies.

This means blur and blink don't stack. Given that mirror image doesn't work by providing a miss chance it would definitely stack with blink at least. All the images would act like they are blinking also.

Was this generally known? I've seen stacking miss chances used several times as a way of having mages survive in combat in various comments here.

[Tehnar]

I would say its pretty unknown. I own the Rules Compendium and didn't notice it, though I did rule that 50% miss chance is as high as you get.

[Dr Bwaa]

This has come up before; my personal view on it is that it makes me sad The real question is how Mirror Image interacts with the others (specifically Blink and Displacement). I've always ruled that Mirror Image stacks with all the others, but the others don't stack at all (since MI gives you multiple selves in completely different squares, whereas the others simply give miss chance based on you being someplace else within your own square (or your square on the ethereal plane)). That is, Mirror Image stacks with Displacement because first your enemies have to target the right image, and then they have to actually hit you, since the real you is still represented as being a little off from where you actually are (but they're targeting the right square, at least).

EDIT @V: When I say stacking, I mean what you said. First, you roll to see if you hit the right person. Then, you roll to see if you actually hit that person.

[Fiery Diamond]

Yeah, pretty unknown. The way I've usually seen it ruled (on this site and in real life) is that instead of "stacking" they apply one after another.

[Lycanthromancer]

The Rules Compendium is flat-out wrong. One effect forces a miss due to them hitting where they think you are, but really aren't, where another forces a miss due to not actually being on the same plane at all.

It's wrong in the same reason that the ToB errata is wrong; it's stupid and wrong.

[Eldariel]

It also disagrees with the "Rules of the Game"-articles, among others, and PHB and DMG. It could be considered an "update", but if so, it's a retarded one. Incorporeal Miss Chance isn't about being in another plane (that'd be flat-out unhittable except in few, very specific cases like Manifesting Ghosts).

It's about being Incorporeal, or a completely metaphysical entity. There's a chance magic works 'cause, well, magic has the possibility of being able to bite into the essence of the creature, but there's also the chance it passes through inefficiently, from where the miss chance comes.

[Sophismata]

The Rules Compendium is flat-out wrong.

This is often the case, mind you. Rules Compendium has no clue what's what half the time.

It's wrong in the same reason that the ToB errata is wrong; it's stupid and wrong.

I thought the only ToB errata was for the Complete Mage..?

[Lycanthromancer]

I thought the only ToB errata was for the Complete Mage..?

This in no way contradicts my viewpoint of it being 'stupid' and 'wrong', and, in fact, reinforces it.

[Runestar]

I agree that miss chances normally should not exceed 50% as that is what is given by being invisible, and I don't think you can really get any more invisible than that.

I suspect the RC ruling is simply to streamline the rules, else things may get complex when you start claiming that miss chances may stem from a variety of reasons and try to stack them.

I doesn't make sense, but it does not bog down the game either.

[Person_Man]

In my games, only the highest miss chance applies. They do not stack, and they are not checked concurrently one after the other. My reasoning:
High level players who use multiple miss chances are ridiculously difficult to hit with anything other then an area of effect spell, and by then they also have Save boosting items and a Ring of Evasion. I have no problem with my players being tough and powerful, but every combat shouldn't be a cake walk. Conversely, enemies who who use multiple miss chances are extremely frustrating for the players to fight. I want players to have fun (most of the time, anyway). Miss chances can also slow down game play dramatically.

[Douglas]

In my games, only the highest miss chance applies. They do not stack, and they are not checked concurrently one after the other. My reasoning:
High level players who use multiple miss chances are ridiculously difficult to hit with anything other then an area of effect spell, and by then they also have Save boosting items and a Ring of Evasion. I have no problem with my players being tough and powerful, but every combat shouldn't be a cake walk. Conversely, enemies who who use multiple miss chances are extremely frustrating for the players to fight. I want players to have fun (most of the time, anyway). Miss chances can also slow down game play dramatically.

My answer to this if I were running a game at the moment would be that just about all miss chances have counters. Both players and their opponents would be expected to have and use the counters, and if they don't then they deserve what they get.

[Person_Man]

My answer to this if I were running a game at the moment would be that just about all miss chances have counters. Both players and their opponents would be expected to have and use the counters, and if they don't then they deserve what they get.

You are correct that miss chances do have counters (though there are probably a few Extraordinary miss chances out there that do not). But does allowing multiple miss chances in your game make them more enjoyable for you or your players? Do they "deserve" to be horribly underpowered if they choose to play a build with no miss chance, while another party member is virtually unhittable because he has 3? Do they deserve to be "taxed" on their feats or abilities (ie, melee builds must take Pierce Magical Concealment in order to have a chance to hit casters, and/or someone in the party MUST be a full caster that learns Greater Dispel Magic).

There are plenty of example of this in 3.5 - Polymorph, Divine Metamagic, etc. I'm not arguing that they should be removed from the game. I'm just saying that it doesn't add anything to the game to allow to allow players or enemies to abuse them.

[Kaiyanwang]

Yeah, pretty unknown. The way I've usually seen it ruled (on this site and in real life) is that instead of "stacking" they apply one after another.

Mee too. It makes more sense by a logical standpoint (see what lycanthromancer said).

If an high level enemy manages to stack them, there are ways to true see (spell, demons) ghost touch (enchants on weapons, jade) and so on..

EDIT: I see other people raised the point..

[Ernir]

I... actually like this rule. Because it makes sense? Nah. But it reduces the bother that is rolling for miss chance multiple times, and nerfs one of the mages' trump cards (easy access to multiple miss chances). Fine by me.

[Emmerask]

Well it doesn´t make sense whatsoever but seeing that it is a raw caster nerf I´m all for it ^^

[Lycanthromancer]

In a very literal sense, no, miss chances don't stack. And several (such as etherealness + blur + mirror image) don't overlap, either.

They're checked in sequence, and if any of them fail, they all do. It's like saying that touch attacks, SR, and saving throws don't stack, and they don't. But if the effect in question requires you to bypass all three, then you have to bypass all three (or fail).

Same thing here.

[Glimbur]

Say I've got Mirror Image, Blink, and Displacement.

If you swing at me, you've got 50% chance of missing from Displacement(or from blink, but they overlap) plus the miss chance from Mirror Image.

If you swing with a magic weapon, you still have 50% chance of missing due to Displacement plus the miss chance from Mirror Image.

If you have True Seeing and a normal weapon, you have a 20% chance of missing due to Blink.

If you have True Seeing and you're using a Force effect or some other way of hitting the Ethereal (Ghost Touch won't do it, Ethereal != Incorporeal), then you don't have a miss chance.

Any disagreement?

[Eloel]

Say I've got Mirror Image, Blink, and Displacement.

If you swing at me, you've got 50% chance of missing from Displacement(or from blink, but they overlap) plus the miss chance from Mirror Image.

If you swing with a magic weapon, you still have 50% chance of missing due to Displacement plus the miss chance from Mirror Image.

If you have True Seeing and a normal weapon, you have a 20% chance of missing due to Blink.

If you have True Seeing and you're using a Force effect or some other way of hitting the Ethereal (Ghost Touch won't do it, Ethereal != Incorporeal), then you don't have a miss chance.

Any disagreement?

I disagree.

With Displacement + Blink + Mirror Image;

If you're swinging for me mundanely, you have a 1/(images+1) chance of swinging AT me due to Mirror Image. That part is not discussable.
Then, you have a 50% chance of actually hitting where I am, thanks to displacement.
On top of that, there's a 20% chance that I am not on the plane you're swinging on when the weapon is supposed to hit me (Blink).

Assuming 3 images, that's a 10% chance of actually hitting me.

[unre9istered]

Then, you have a 50% chance of actually hitting where I am, thanks to displacement.
On top of that, there's a 20% chance that I am not on the plane you're swinging on when the weapon is supposed to hit me (Blink).

The 50% from displacement doesn't stack with the 20% from blink. The RAW is if you have multiple sources of miss chance you only use the highest. Kind of like how if you have damage reduction 10/magic and 2/- you only use one or the other even if they are from different sources. The 10/magic will apply to nonmagic and the 2/- would apply to magic weapons.

[Eloel]

The 50% from displacement doesn't stack with the 20% from blink. The RAW is if you have multiple sources of miss chance you only use the highest. Kind of like how if you have damage reduction 10/magic and 2/- you only use one or the other even if they are from different sources. The 10/magic will apply to nonmagic and the 2/- would apply to magic weapons.

I thought we were going for RAMS? Isn't that why we're discussing?

[unre9istered]

I thought Glimbur's question was meant to be by RAW.

BTW Glimbur, by my reading you're correct.

[Riffington]

I thought we were going for RAMS? Isn't that why we're discussing?

Surely RAMS, no combination should be able to give a better miss chance than "I close my eyes"?

[Eloel]

Surely RAMS, no combination should be able to give a better miss chance than "I close my eyes"?

Your miss chance for sight is 50% - the 'I close my eyes' thing.

Then there's the etherealness bit of the blinky guy. When you attack (eyes closed, whatever), there's a 20% chance he isn't there.
How you hit him when he isn't there is beyond me.

[Eldariel]

Actually, it's not really a "miss chance" in the same way concealment-based effects. It's a chance to miss 'cause you are on another plane! Those two are completely unrelated

See this and this on the subject. But basically, Incorporeal "Miss Chance" is there because you aren't actually hitting anything but air and the only way for you to influence a bodiless creature's existence is if your magic can impact its essence. Ethereal "Miss Chance" exists because you've got a chance to be on another friggin' plane. GL hitting something not there.

And Concealment "Miss Chance", which is the actual miss chance which does not stack, happens 'cause you can't see what you're hitting and thus have some trouble aiming properly. All 3 of those stack just fine (only one of those is an actual miss chance; the others are chance of your attack having any effect on the arcane creature you're hitting, and the chance of your opponent being on the plane you're attacking), if something claims something to the contrary it's flat-out wrong and I think that's the case with Rules Compendium.


And honestly, don't want to roll that much? Miss Chance for 50%+20% = 60%. Miss Chance for 50%+50% = 75%. You're fine with one die regardless of what's going on. Of course, if someone has Blind-Fight they'll have to roll separately if concealment is one of the miss chances being dealt with here. But as they took a feat that doubles their rolling anyways, they are apparently fine with rolling lots of dice and thus it becomes a non-issue either way.

[ericgrau]

It's not just the rules compendium, I've seen it in the SRD before. I didn't realize it wasn't common knowledge. Now it's a matter of whether or not I'm too lazy to find it again, or if someone else will.

EDIT: Ah, this was easy to find, though perhaps only a partial answer:

Concealment Miss Chance
Concealment gives the subject of a successful attack a 20% chance that the attacker missed because of the concealment. If the attacker hits, the defender must make a miss chance percentile roll to avoid being struck. Multiple concealment conditions do not stack.

[2xMachina]

That just says Concealment Miss Chance right?

So, your Blur does not stack with Displacement. But stacks with Mirror Image (since not miss chance).

Blink is also not concealment miss chance, unless they're capable of hitting ethereal anyway. It's just Miss Chance, not from concealment.

(Or you want to be complex... 30% miss chance is due to plane shifting, 20% is due to concealment. 20% doesn't stack, the 30% does.)

EDIT: Actually, with how stacking works, 'not there' miss chance is 3/8.

[Riffington]

Your miss chance for sight is 50% - the 'I close my eyes' thing.

Then there's the etherealness bit of the blinky guy. When you attack (eyes closed, whatever), there's a 20% chance he isn't there.
How you hit him when he isn't there is beyond me.

I thought we were talking about displacement and mirror image, which the attacker should be able to sum to 50%.
Blink is a very special case: best to go with RAW on it.
(RAMS, it should screw up the caster's attacks/defenses much more than it does by RAW. After all, if they're swinging at you, 50% of the time you aren't there at the moment of impact. But during many such blows, you materialize while the sword is in your head, moving you 5', doing d6, and provoking an attack of opportunity. And plenty of time, the sword just bypasses the arm you throw up to block it, but hits your head solidly. Calculating all that out is madness, and very bad for the caster. Far fairer to just play it by the rules)

[2xMachina]

I always thought that should you materialize while the sword is where your head should be, you just take the hit.

Calcy thing...

We know for sure 20% miss chance is from concealment (stated). You get 50% miss chance in total. Thus, 80% of the time, when concealment doesn't help, you STILL miss a % of the time due to not being there. This would be 3/8 chance to give you a total of 50% miss chance.

So, displacement + mirror + blink should make you roll for mirror image if you spread them out (pick the right square), then displacement (is it really there? 50%), then blink's (not there now 3/8).

I think Mirror image lets you have the images on different 5" square too (just within 5" of 1 image). So, even if you close your eyes, you still have to pick the right square, then 50%, the blink.

[Riffington]

I I think Mirror image lets you have the images on different 5" square too (just within 5" of 1 image). So, even if you close your eyes, you still have to pick the right square, then 50%

Closing your eyes defeats mirror image per spell text.

[ericgrau]

Another note on blink:

If the attack is capable of striking ethereal creatures, the miss chance is only 20% (for concealment).

If the attacker can see invisible creatures, the miss chance is also only 20%. (For an attacker who can both see and strike ethereal creatures, there is no miss chance.) Likewise, your own attacks have a 20% miss chance, since you sometimes go ethereal just as you are about to strike.

It seems the miss chance from blink is part concealment and part etherealness. IMO combining blink with displacement would net a 50% miss chance plus - if we ignore rules compendium and assume only concealment doesn't stack - another 20% miss chance not 50%.

I think Mirror image lets you have the images on different 5" square too (just within 5" of 1 image). So, even if you close your eyes, you still have to pick the right square, then 50%, the blink.

Closing your eyes defeats mirror image per spell text.

Wow, that's a really easy counter if you have a good listen modifier. It's a DC 20 to find someone's square whenever he attacks or casts or etc. I'll have to remember that one. Especially if I make a blindfighting character or monster. The 50% is from blindness, btw, and still applies. Or essentially 25% with blindfight.