Blind creatures lack the usual LoS mechanics. Instead a given creature may have other ways, mundane or magical to navigate the dungeon.
SONAR - Lurkers have sight near sources of noise, with a larger noise granting a correspondingly larger sight radius, this sight radius diminishes as the noise dissipates
Lurker sight is not blocked by clouds
Lurkers can shout to see briefly
Lurkers following Qazlal can see pretty well
Lurkers are unaffected by both darkness and haloes
Creatures nearby that are not within the range of a source of noise are treated as invisible to the player
Lurkers (Example Race):
Lurkers are a race of blind quadrupedal reptilian creatures with spear-like limbs and massive jaws. They navigate using sonar.
Lurkers make good Monks, Enchanters, Transmuters, and Earth Elementalists.
10 Str, 5 Int, 10 Dex
EXP +1
HP +2
MP 0
MR +5
Lurkers are blind
SONAR
Lurkers can not wear armour
Lurkers have no thumbs and can not manipulate items
Lurkers can constrict a creature with unarmed attacks (By impaling them on their arms)
Lurkers can use 'v' to reach like polearm users; creatures struck this way may be impaled and brought in close, constricting them
Lurkers can attempt to swallow a constricted creature, this is easier against smaller creatures and takes some time, but restores nourishment
Lurkers' scales are resistant to fire, ice, and electricity, and Provide some AC. These scales grow more resistant as the Lurker grows in level
Aptitudes
Fighting +1
Unarmed +2
Dodge +1
Stealth +2
Invoc +2
Evoc -3
Spellcasting -1
Conjur -2
Hexes +2
Charm 0
Summon -2
Necro +1
Transloc -2
Transmu +1
Fire -1
Ice -1
Air +1
Earth +3
Pois 0