Darkness and Blinding

[Kingsnake]

Are creatures in a completely dark area considered blinded? That is, do they suffer the full effects? Say I'm bound to Tenebrous, and I use his vestigial powers to radiate a Deeper Darkness SLA, which I can still see through. Is the thug I'm fighting denied his dex bonus to AC? The PHB says that complete darkness grants full concealment, and the fact that it's listed separately from blinding indicates (to me, at least) that they're meant to be handled differently, but being unable to see is exactly what blindness is. I'm not certain, so I turn to you folks. Is there a definitive answer here?

[Troacctid]

They're not blinded per se, because they can still see outside of the darkness, unless it's magical darkness created by an effect that specifically says otherwise. For example, if you are in a completely dark theater and someone shines a spotlight onto an actor on the stage, you can see them, even though you yourself are currently in an area of total darkness. (This is not in the core rules, but it is clarified in the Rules Compendium.)

However, for the purposes of seeing inside the darkness, yes, they are essentially blinded with respect to you, as you will be considered invisible to them, which gives you a +2 bonus to your attacks and allows you to ignore their Dexterity bonus to AC.

[Umbranar]

In magical Darkness and even Deeper Darkness you merely get 20% concealment:

From the srd (darkness):

"This spell causes an object to radiate shadowy illumination out to a 20-foot radius. All creatures in the area gain concealment (20% miss chance)."

From the srd (deeper darkness):

"This spell functions like darkness, except that the object radiates shadowy illumination in a 60-foot radius and the darkness lasts longer."

So if there is light outside the darkness people can see you just fine but just blurry (20% miss chance).
As I understand it if there is no outside light source everyone gets "blinded" anyway by the natural darkness but creatures with Darkvision can see just fine albeit with a 20% miss chance as the area still has shadowy illumination.

The vestige power of Tenebrous lacks the crucial text that you can not hide in this darkness so with a descent hide you can hide in the darkness (but not while being observed).

[Segev]

One of the genuine dysfunctions in the rules is that there is no conditional language on the darkness line of spells. They "radiate shadowy illumination" that sets the light level. It does not say "reduces to" nor present any language which would indicate that it fails to have the same effect in natural darkness. Therefore, by the RAW, it does, in fact, make it easier to see for creatures without Darkvision if the area was otherwise darker than "shadowy illumination."

It is perfectly reasonable to house-rule otherwise, of course. The idea that darkness makes natural pitch darkness brighter is a bit silly, and it hurts nothing to change it.

[Kingsnake]

In magical Darkness and even Deeper Darkness you merely get 20% concealment:

From the srd (darkness):

"This spell causes an object to radiate shadowy illumination out to a 20-foot radius. All creatures in the area gain concealment (20% miss chance)."

From the srd (deeper darkness):

"This spell functions like darkness, except that the object radiates shadowy illumination in a 60-foot radius and the darkness lasts longer."

So if there is light outside the darkness people can see you just fine but just blurry (20% miss chance).
As I understand it if there is no outside light source everyone gets "blinded" anyway by the natural darkness but creatures with Darkvision can see just fine albeit with a 20% miss chance as the area still has shadowy illumination.

The vestige power of Tenebrous lacks the crucial text that you can not hide in this darkness so with a descent hide you can hide in the darkness (but not while being observed).
A translation error; my group, like so many others, is effectively running 3.25, and I only have the third edition PHB, in which the Darkness line of spells was much more effective, radiating actual darkness, as opposed to simply shadow.

But it does radiate shadow; functionally, anyway. If "Normal lights" "are incapable of brightening the area", then it wouldn't matter if there was light outside the spell's area of effect (unless it came from a higher level spell); light doesn't work differently depending on where the source is.

[Troacctid]

But it does radiate shadow; functionally, anyway. If "Normal lights" "are incapable of brightening the area", then it wouldn't matter if there was light outside the spell's area of effect (unless it came from a higher level spell); light doesn't work differently depending on where the source is.

Since it is an area of shadowy illumination, it itself is a light source, as bright as a candle. It just happens to also reduce the illumination level to candlelight-equivalent, even if the prevailing conditions would be brighter. Of course, if you're for whatever reason using the more powerful 3.0 version of Deeper Darkness, then it's more powerful, obviously. I'm not sure I'd recommend that--Tenebrous is balanced around the 3.5 version, so you'd be making him a lot stronger compared to other vestiges of the same level.

The location of the light source is certainly relevant, BTW, as light sources have a limited range; a light that's too far away is useless.