Total Concealment clarifications

[Jair Barik]

Okay, so a creature with total concealment can be attacked by ranged or close combat attacks if they are targeted at the square the creature is in but these have a 50% chance to miss. I get that much, but I need some clarifications for some other aspects of it.

As I understand it if a spell has an area descriptor then it effects creatures with total concealment normally but if it has a targetted descriptor (confusion, magic missile) then it can't be used against a creature with total concealment, a ray can though as it isn't targetted it is a ray (miss chance still applies).

If the creature is invisible then spot checks can be made to see them but not if they just have total concealment right?
So what about Shadow dragons (Dracomnicon) and Spore bats (FF)? They have extraordinary/supernatural total concealment in any light conditions other than daylight. So does this mean they are effectively invisible but cannot be seen with a spot check? True seeing doesn't look like it would work as it doesn't pierce concealment. Now in the case of the shadow dragon that is dangerous but not impossible. A daylight spell will see it off and even without that you can still hear it and its size should help with targetting a square that it is filling but the sporebat is silent. Auto passing move silently checks as far as I can tell and only taking up a 5ft square. Now it has an awful save DC on its ability and weak attacks for its CR but without daylight it seems the only way to deal with it reliably is retreat. You can't locate it very easily so beyond spamming AoE's everywhere I can't see how you fight the things.

Is there something I'm missing here?

[Gwendol]

As far as I understand, no. Can't you use blindsight, scent, etc to detect it though? Use as trigger to cast daylight.

[Yuki Akuma]

You can see someone who has total concealment who is actively hiding with a spot check.

Usually, you can only hide if you have total concealment.

[Gwendol]

Let's see what the SRD has to say:

Concealment
To determine whether your target has concealment from your ranged attack, choose a corner of your square. If any line from this corner to any corner of the target’s square passes through a square or border that provides concealment, the target has concealment.

When making a melee attack against an adjacent target, your target has concealment if his space is entirely within an effect that grants concealment. When making a melee attack against a target that isn’t adjacent to you use the rules for determining concealment from ranged attacks.

In addition, some magical effects provide concealment against all attacks, regardless of whether any intervening concealment exists.

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.

Concealment and Hide Checks
You can use concealment to make a Hide check. Without concealment, you usually need cover to make a Hide check.

Total Concealment
If you have line of effect to a target but not line of sight he is considered to have total concealment from you. You can’t attack an opponent that has total concealment, though you can attack into a square that you think he occupies. A successful attack into a square occupied by an enemy with total concealment has a 50% miss chance (instead of the normal 20% miss chance for an opponent with concealment).

You can’t execute an attack of opportunity against an opponent with total concealment, even if you know what square or squares the opponent occupies.

So no, you don't need total concealement to hide; only concealement. And no, you don't necessarily spot creatures with total concealement, since you don't have line of sight (exceptions apply, such as for invisibility).

[kabreras]

IIRC Magic missile hit you, whatever your concealment is.

[2xMachina]

If you can target. I think Total concealment removes LoS, so you can't target.

[Curmudgeon]

You can see someone who has total concealment who is actively hiding with a spot check.

Usually, you can only hide if you have total concealment.
You're mixing up concealment (satisfies one of the two requirements to Hide) with total concealment (makes it impossible to have line of sight, so no Hide check is needed).

See the rules about concealment here (http://www.d20srd.org/srd/combat/combatModifiers.htm#concealment); also see the Hide skill rules here (http://www.d20srd.org/srd/skills/hide.htm).