Dark-squared bishop

A dark-squared bishop is the bishop whose movement is confined to dark squares. Because every move follows a diagonal, it always finishes on the same square color from which it began.

In the standard starting position, White's dark-squared bishop is on c1, the square in vertical column c and horizontal row 1, and Black's is on f8, column f of row 8. “Dark-squared” refers to the set of squares the bishop can use, not to the bishop belonging to Black.

It can directly attack, defend, or occupy only the thirty-two dark squares. It can never act directly on a light square, although it can cooperate with other pieces that control one. Its activity depends on open dark-square diagonals and useful targets along them. It is a minor piece, the category formed by bishops and knights.

Promotion transforms a pawn when it reaches the farthest row. If the player chooses a bishop on a dark promotion square, a new dark-squared bishop appears. A player can therefore have more than one.