A character with this proficiency has trained
himself to respond to sound, smell, and touch stimuli, and thus is
less hampered by completely dark conditions than normal characters
are. Blind-fighting proficiency is available to all character
races, but is obviously most useful to those not possessing infravision.
This proficiency can be used whenever a character cannot
see, whether the reason is darkness, a blindfold, or some
kind of natural or magical blindness.

A character with blind-fighting proficiency suffers only a -2 on
all attack and damage rolls, and saving throws, instead of the
standard -4. Such characters suffer no penalties to their Armor
Class because of darkness, and retain special abilities that would
normally be lost in darkness. Thus, a thief with blind-fighting proficiency
could still score extra damage for a backstab in the dark,
and likewise, a ranger would still inflict extra damage on giantclass
creatures.

In addition, the chance of the character stumbling over a dropoff
or falling from a sheer surface because of darkness is reduced
to half that of a nonproficient character (i.e., the Dexterity reduction
is only 1, and the Climbing Rating penalty is only -5%).

Q: Does the blind-fighting proficiency
aid a character when fighting invisible
creatures?

A: Yes, indeed. The blind-fighting proficiency's bonuses
(only -2 to attack, damage,
and saving rolls, no AC penalty, and retention
of special abilities) apply in any situation
in which a character cannot see his
opponent. This includes darkness, blindness,
and all magical effects that render
the opponent unable to be seen.
(118.58)

Blind-fighting: A character with this proficiency is less hampered
by the absence of daylight than are characters who do not
possess this skill. His penalty on attack and damage rolls in total
darkness is only -2 instead of -4; in natural darkness, his penalty
is only - 1 instead of -3; and in any conditions of brighter illumination
he suffers no penalties. (See the text on “Fighting in
Poor Visibility” in the section on Combat Rules for Wilderness
Play.) A character with proficiency in blind-fighting suffers no
penalty to armor class because of lack of illumination (he is just
as hard to hit as he would be in daylight), and he retains special
abilities and other proficiencies that would otherwise be lost in
darkness. For instance, a character with blind-fighting proficiency
and proficiency in direction sense would still be able to
find his way around during a long journey in the dark (assuming
that the Proficiency Check for direction sense is successful); a
character with proficiency in tracking and in blind-fighting would
still be able to follow a trail in total or natural darkness.
This proficiency also reduces the character’s chance of stumbling
or falling over an obstacle in his path during total or natural
darkness, the chance of tumbling into a pit or over a cliff, and the
chance of slipping and falling while climbing. In all such cases,
the chance of an adverse occurrence is half that of a character
without this proficiency.

Exceptions: Proficiency in blind-fighting does not impart the
ability to see across long distances in the dark; the improved visual
acuity granted by this skill only pertains to short-range uses of
vision such as for tracking, in melee combat, and in the use of the
fire-building proficiency. It does not enable the character to see
out to the maximum range of visibility that would otherwise apply
in daylight conditions, or to perform any skill or function that necessarily
involves long-range vision.