Blindsense and See Invisibility

[carrdrivesyou]

Say I have a character with both a constant See Invis as well as 30ft blindsense, does that character automatically know when someone is within 30ft of them? Do I need to make spot checks? Do rogues and other sneaky types still need to make their move silent/hide checks to get the drop on me?

[Aracor]

You automatically penetrate MOST forms of stealth in that case. If the sneaky character has the Darkstalker feat, then you still need to roll as per normal. There are also a few obscure forms of invisibility and/or stealth that can get around your abilities.

[Paragon]

Blindsense say "The creature usually does not need to make Spot or Listen checks to pinpoint the location of a creature within range of its blindsense ability, provided that it has line of effect to that creature"

First case scenario : you automatically detect people mundanely hiding if you have line of effect to them (like those Hide in Plain Sight) but do not "see" them meaning you get the usual penalties associated with total concealment.

Second case : you also automatically detect invisible people but those ones you can actually "see" thanks to See Invisibility so you do not need to roll a Spot of Listen (usually) and just downright see them. They can't use their sole "being invisible" trick to hide from you.

Last case scenario, ethereal people avoid your blindsense since they're on another plane, but you can still see them thanks to See Invisibility. Meaning if ethereal people hide from you using HiPS for instance, you do not detect them and do need to roll a Spot check vs their Hide check.

And don't forget about Darkstalker feat that makes you need to roll Spot/Listen against those that possess it anyways.

[Biggus]

Usually you'll know automatically when someone is there, but there are ways round them.

Blindsense will normally tell you somebody is within 30ft of you, but if the enemy has the Darkstalker feat (Lords of Madness p.179) you have to make Spot and Listen checks as normal.

See Invisibility is defeated by the spell Superior Invisibility (Spell Compendium p.125).

Also, note that blindsense still leaves you with a 50% miss chance against an opponent if you fail your Spot check against them.

Edit: bah, double ninja'd on the Darkstalker part.

[Tzardok]

Blindsense can't sense incorporeal creatures. You won't notice an incorporeal creature that's actively hiding.

[Biggus]

Blindsense can't sense incorporeal creatures.

Can't it? Where does it say that?

[Tzardok]

Can't it? Where does it say that?

In the SRD.


An incorporeal creature moves silently and cannot be heard with Listen checks if it doesn’t wish to be. [...] Nonvisual senses, such as scent and blindsight, are either ineffective or only partly effective with regard to incorporeal creatures.

[Troacctid]

Blindsense also doesn't detect mundane disguises. This could potentially cause you to misidentify a creature. In some cases, that can be just as bad as not spotting them—imagine a stone golem standing perfectly still to mimic a statue, for example.

[Biggus]

In the SRD.

That says it's "either ineffective or only partly effective". What's your basis for concluding it's in the "ineffective" part, not the "partly effective" part?

[Tzardok]

Of course we can't be quite sure unless we know what sensations the blindsense exactly perceives, but as the usual examples given for blindsight we have "sensitivity to vibrations, acute scent, keen hearing, or echolocation" or a combination thereof. Keen hearing doesn't work unless the incorporeal creature allows it. Incorporeal creatures don't have a smell unless specifically noted, so that one is out. Echolocation would just go through it as it's not solid, nor any kind of matter at all. And vibrations, well, guess what incorporeal creatures don't cause if they touch anything?

Furthermore, blindsense is already given as a weaker form of blindsight, so I'm not sure what "partial functioning" would even look like. Therefore I'll assume that blindsense won't work on a random incorporeal creature unless either the blindsense's or the creature's fluff or mechanics say something else.