Blindsight question

[GrassyKnoll]

Sorry if this has been asked before, I had a look, but I am not a member to use the search function

How does Blindsight (the spell) work with regard to attacks such as sneak attacks from Rogues? If someone outside of the 30' radius comes into the area of the spell (assume they can move quicker, or a double move), is the Blindsighted person now aware of a possible attack and therefore not dennied their dex and thus not sneak attacked? Or do they become aware of the fact that they are being attacked, but can do nothing until there round?

Thanks, and if possible, an explanation will be excellent rather than a simple yes or no

 

[kreynolds]

If someone outside of the 30' radius comes into the area of the spell (assume they can move quicker, or a double move), is the Blindsighted person now aware of a possible attack and therefore not dennied their dex and thus not sneak attacked?

Yes, they are aware. Generally, blindsight allows the creature to automatically sense the location of creatures within the area. As soon as the rogue steps within the 30 foot radius, the creature knows the rogue is there. Blindsight does not, however, negate flanking.