Blindsight

[Eltern]

Questions about blindsight:
If someone has blindsight, is there -any- reason to have tremorsense or scent? I realize scent can be used with tracking, but other than that...

Does tremorsense or scent cover some ascpect of "sensing" that blindsight does not?

I've been told that blindsight only works on a "line of effect" (not sight) basis, but I haven't seen that in any books. I thought that blindsight was basically a mesh of scent, tremorsense, and good ears. If it's sound based, then hearing through walls would work, but it would be hampered (DC for listen checks go way up with stone walls). Unfourtanetly we have no real rules for this, I don't think, because blindsight is just supposed to "work" and there's no rules for rolling listening checks. In fact, what do you do if a sneaky rogue goes in your blindsight radius? Do you hear him, or no? Depends on how good he is?

The Grimlock explicitly works on both sound and scent...

Eltern

 

[Steve Jung]

Blindsense (Ex): Using nonvisual senses, such as acute smell or hearing, a creature with blindsense notices things it cannot see. 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. Any opponent the creature cannot see still has total concealment against the creature with blindsense, and the 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.

Blindsight (Ex): This ability is similar to blindsense, but is far more discerning. Using nonvisual senses, such as sensitivity to vibrations, keen smell, acute hearing, or echolocation, a creature with blindsight maneuvers and fights as well as a sighted creature. Invisibility, darkness, and most kinds of concealment are irrelevant, though the creature must have line of effect to a creature or object to discern that creature or object. The ability’s range is specified in the creature’s descriptive text. The creature usually does not need to make Spot or Listen checks to notice creatures within range of its blindsight ability.

Scent (Ex): This special quality allows a creature to detect approaching enemies, sniff out hidden foes, and track by sense of smell. Creatures with the scent ability can identify familiar odors just as humans do familiar sights.
The creature can detect opponents within 30 feet by sense of smell. If the opponent is upwind, the range increases to 60 feet; if downwind, it drops to 15 feet. Strong scents, such as smoke or rotting garbage, can be detected at twice the ranges noted above. Overpowering scents, such as skunk musk or troglodyte stench, can be detected at triple normal range.
When a creature detects a scent, the exact location of the source is not revealed—only its presence somewhere within range.
Whenever the creature comes within 5 feet of the source, the creature pinpoints the source’s location.

Tremorsense (Ex): A creature with tremorsense is sensitive to vibrations in the ground and can automatically pinpoint the location of anything that is in contact with the ground. Aquatic creatures with tremorsense can also sense the location of creatures moving through water.

Emphasis mine. Blindsight appears to be the best. Tremorsense won't work on flying creatures and scent can't give the user a location until the source is within 5 feet.

 

[Eltern]

Just for my information, what encompases "usually" for usually not needing to make Spot/Listen checks? Would something like anyone who's making a move silently check under 20 is automatically seen, all else you need to make a listen check?

30?

40?

Spot obviously will never happen, as it's visual based and this property just bypasses that, so...Never make Spot checks

Eltern

 

[Steve Jung]

Just for my information, what encompases "usually" for usually not needing to make Spot/Listen checks? Would something like anyone who's making a move silently check under 20 is automatically seen, all else you need to make a listen check?

30?

40?

Spot obviously will never happen, as it's visual based and this property just bypasses that, so...Never make Spot checks

Eltern

I don't know. The descriptions for Spot and Listen don't mention anything.

 

[jgsugden]

If a creature is behind a door, blindsense/blindsight is useless. Tremorsense has no problem locating the target. Scent may or may not be able to locate the target, at the DMs option.

If a creature is approaching from underground, scent and blindsense/blindsight are useless, but tremorsense should locate that creature.

 

[LoneWolf23]

Not exactly an answer, but another thought: It would make sense to seperate Blindsight into sub-categories based on the sense used for it, such as Blindsight (Hearing), or Blindsight (Scent). Then, you state that each category is vulnerable to a type of attack. Blindsight (Hearing) could be disrupted by sound-based magic for exemple, and Sonic attacks could damage it.

 

[Eltern]

If a creature is behind a door, blindsense/blindsight is useless. Tremorsense has no problem locating the target. Scent may or may not be able to locate the target, at the DMs option.

If a creature is approaching from underground, scent and blindsense/blindsight are useless, but tremorsense should locate that creature.

If you have blindsight that's based on tremors and/or scent though, then you would notice them.

Eltern