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Fouredged Sword
2010-06-17, 04:10 PM
Ok, a sleeping ashworm has blindsense 60ft. Ok, so it is sleeping underground and guarding a set of camels just over it's head. Would there be a check to see if anything was sneaking up on the camels? Blindsense states that there is normaly no check for detecting a creature, but is doing so while asleep underground normal?

Shhalahr Windrider
2010-06-17, 05:15 PM
Unless a description says otherwise, it’s probably best to assume most don’t function to full capacity when a creature is asleep. If the creature’s blindsense is sound-based, though, they should be able to make any appropriate Listen checks, though, as one can usually still make a Listen check and be woken up by a sufficiently loud noise.

Ernir
2010-06-17, 05:58 PM
There's really no off-button on most senses. There's a -10 penalty on listen checks when you're asleep (and sight-based spot checks autofail because your eyes are closed), but since there are no checks involved when something enters your Blindsense range, you just notice it.

I imagine it's fantastically annoying trying to fall asleep when you have this stuff on 24/7, actually...

Shhalahr Windrider
2010-06-17, 06:10 PM
I imagine it's fantastically annoying trying to fall asleep when you have this stuff on 24/7, actually...
Which is why it makes sense that there would be at least reduced sensitivity in a given sense while asleep.

Keep in mind that there are no checks for smell or touch in D&D, either, yet it still takes a bit of effort to wake someone with one of those senses.

Jack_Simth
2010-06-17, 06:41 PM
Relevant Link (http://www.d20srd.org/srd/specialAbilities.htm#blindsightAndBlindsense)

Blindsight And Blindsense

Some creatures have blindsight, the extraordinary ability to use a nonvisual sense (or a combination of such senses) to operate effectively without vision. Such sense may include sensitivity to vibrations, acute scent, keen hearing, or echolocation. This ability makes invisibility and concealment (even magical darkness) irrelevant to the creature (though it still can’t see ethereal creatures and must have line of effect to a creature or object to discern that creature or object). This ability operates out to a range specified in the creature description.

The creature usually does not need to make Spot or Listen checks to notice creatures within range of its blindsight ability. Unless noted otherwise, blindsight is continuous, and the creature need do nothing to use it. Some forms of blindsight, however, must be triggered as a free action. If so, this is noted in the creature’s description. If a creature must trigger its blindsight ability, the creature gains the benefits of blindsight only during its turn.

* Blindsight never allows a creature to distinguish color or visual contrast. A creature cannot read with blindsight.
* Blindsight does not subject a creature to gaze attacks (even though darkvision does).
* Blinding attacks do not penalize creatures using blindsight.
* Deafening attacks thwart blindsight if it relies on hearing.
* Blindsight works underwater but not in a vacuum.
* Blindsight negates displacement and blur effects.

Blindsense

Other creatures have blindsense, a lesser ability that lets the creature notice things it cannot see, but without the precision of blindsight. The creature with blindsense usually does not need to make Spot or Listen checks to notice and locate creatures within range of its blindsense ability, provided that it has line of effect to that creature. Any opponent the creature cannot see has total concealment (50% miss chance) against the creature with blindsense, and the blindsensing creature still has the normal miss chance when attacking foes that have concealment. Visibility still affects the movement of a creature with blindsense. A creature with blindsense is still denied its Dexterity bonus to Armor Class against attacks from creatures it cannot see. (Emphasis added)

Both Blindsight and Blindsense require line of effect. If you're underground, no, you don't get to see them sneaking up on you, because you do not have line of effect.

However, nothing in the rules prevents the critter from it's normal use of Listen to waken (other than the rather large penalty for being asleep and listening through barriers).

KillianHawkeye
2010-06-17, 06:47 PM
^ Ashworms actually have Tremorsense, not Blindsense.

Jack_Simth
2010-06-17, 06:56 PM
^ Ashworms actually have Tremorsense, not Blindsense.
Oh. Tremorsense (http://www.d20srd.org/srd/specialAbilities.htm#tremorsense) doesn't have LoE clauses. So the Ashworm will want to go down far enough that the surface is not within it's tremorsense range to get a good night's sleep. Otherwise, it automatically detects those sneaking up on the camels. Now, whether detecting something and that detected something waking the sleeping critter are different matters. But the DM is well within his rights to say "the people stealthily walking up to the camels are immediately noticed by the Ashworm when they come within sixty feet" unless they've got Darkstalker, some way to avoid the ground, or similar.