Spells and Miss Chance

[dutorn]

If I cast Blur, Darkness, and Obscuring Mist is my miss chance 60%? Or is it three rolls of 20% miss chance per each attack? Assume no darkvision or true seeing or any of that stuff that negates these spells.

 

[Zurai]

3 rolls of 20%, or if your DM wanted to lessen the rolling, 1 roll of 49% miss chance.

 

[dutorn]

What's the equation to get 49%

 

[Wolfwood2]

What's the equation to get 49%

Each condition grants an 80% chance of success.

.8 x .8 x .8 = 0.512 (51.2%) chance of success, which means a 48.8% chance of failure. Round up to 49%.

 

[werk]

They are all concealment bonuses, and I'd say that concealment stacks.

OOPS!

"Multiple concealment conditions do not stack."

so 20% then. If you want to totally disregard that rule, then 50% in total concealment.

 

[gunderval]

Don't stack

Cumulative miss chances don't stack, so I think that 20%, the same way 6 +1 morale bonuses are +1. Simple and works against power gaming.

See the rules on concealment and cover in combat section of PHB etc.

 

[Zurai]

"Multiple concealment conditions do not stack."

Good find. 1 roll of 20% it is then!

 

[LonePaladin]

It's important to note that all three of those spells produce the same miss chance in different ways. Darkness simply turns the existing lighting conditions to shadowy, but can be foiled with a high-enough level light spell or the 'see in darkness' ability (which, IIRC, some demons have). Blur is an illusionary effect, which can be foiled by true seeing, or other means of seeing through illusions. Obscuring mist is the hardest to get past, because it blocks sight through physical means. You generally have to produce a strong wind to get rid of it.

Having all three of these generally means that any creature that relies on sight has to deal with the fact that you're harder to see.

 

[Hypersmurf]

Note that it is possible to stack multiple percentage chances to avoid damage, as long as only one of them derives from concealment - for example, a wraith in the middle of Obscuring Mist would receive a 20% miss chance, and also a 50% chance to avoid damage from an corporeal source, for an effective 60% chance of being unaffected by an attack.

The Blink miss chance is an interesting one, since it appears to be sometimes derived from concealment (for example, if the opponent can strike ethereal creatures), and sometimes not.

Unless the opponent can strike ethereal creatures, it would seem that Blink would stack with concealment and also with incorporeality - there's a 50% chance you're on another plane, and if you aren't, there's a 50% chance the attack passes right through you, and there's also a 20% chance that they just swing at the wrong spot anyway...

-Hyp.