Player's Handbook[]
A character with blind-fighting is skilled at fighting in conditions of poor or no light (but this proficiency does not allow spell use). In total darkness, the character suffers only a -2 penalty to his attack roll (as compared to a -4 penalty without this proficiency). Under starlight or moonlight, the character incurs only a -1 penalty. The character suffers no penalties to his AC because of darkness.
Furthermore, the character retains special abilities that would normally be lost in darkness, although the effectiveness of these are reduced by one-half (proficiency checks are made at half the normal score, etc.). This proficiency is effective only against opponents or threats within melee distance of the character. Blind-fighting does not grant any special protection from missile fire or anything outside the immediate range of the character's melee weapon. Thus, AC penalties remain for missile fire. (By the time the character hears the whoosh of the arrow, for example, it is too late for him to react.)
While moving in darkness, the character suffers only half the normal movement penalty of those without this proficiency.
Furthermore, this skill aids the character when dealing with invisible creatures, reducing the attack penalty to -2. However, it does not enable the character to discover invisible creatures; he has only a general idea of their location and cannot target them exactly.
Player's Option: Skills & Powers[]
This allows characters to ignore many of the problems inherent in fighting without being able to see. In total darkness, the character suffers –2 (not –4) to attack rolls, and suffers no penalties to AC versus melee attacks. In starlight or moonlight, the character suffers only a –1 penalty to attack rolls.
When moving in darkness, the character is allowed to make a proficiency check at the beginning of a round; success means no movement penalties are assessed because of the darkness, while failure means the normal penalty applies.
When in combat with an invisible creature, the character with blind-fighting proficiency suffers only a –2 to attack rolls, but gains no benefit toward discovering the creature.
The Complete Book of Dwarves[]
Blind-fighting is cheaper for dwarves; they only gain the benefit when fighting invisible opponents. Their inherent infravision allows them to fight effectively, even in total darkness.
The Complete Book of Humanoids[]
See the Player's Handbook for full details on this proficiency. In general terms, this proficiency reduces the penalty for fighting while blinded from -4 to -2. It similarly reduces the penalty for fighting invisible opponents. Because many humanoids have infravision, this proficiency is not usually as useful for humanoids as it is for humans.