Facing

One of eight possible directions a character can face, corresponding to each of the sides and corners of a square. This determines which squares a character threatens, and from which squares a character is most vulnerable.

Types of Squares
There are three types of squares: Threatened Squares, Neutral Squares, and Blind Squares.

Threatened Square
Threatened squares (represented by  the  green "T"s  ) are squares whose occupants can be attacked by a character. In addition, a character applies their full guard bonus against characters in these squares.

Shielded Squares
Shielded squares (represented by the blue "S"s and magenta magenta "S"s, for a shield worn on the left hand and right hand, respectively), are squares whose occupants a character may not attack, but may apply their shield bonus against.

Blind Square
The Blind square (represented by the red "B" ) is the most beneficial square to an enemy, and the most dangerous to a character. A character may not attack or guard against characters occupying this square, and any action they take other than turning provokes an attack of opportunity. In addition, characters attacking  from  a character's blind square gain the following benefits:
 * They gain a +5 on all attack's rolls against the character
 * Their critical protection is treated as 2 lower (a 19-20 range becomes 17-20, and a 17-20 range becomes 15-20).
 * A successful attack deals an additional 1d6 points of damage.

Neutral Squares
A neutral square is any square that doesn't fall into the first two categories. A character may not attack a character occupying one of these squares. However, they may still guard against them, albeit at a -2 penalty.