Dark square

A dark square is one of the 32 darker squares on the eight-by-eight board. Dark squares alternate with light squares across every horizontal row and vertical column. The name marks a stable visual category even when a board uses brown, green, blue, or another shade instead of black.

With the chess set oriented correctly, each player's near-left corner is dark and the near-right corner is light. If the near-right corner is dark, the physical board has been rotated by a quarter turn.

Bishops never change square color because every diagonal move takes them to another square of the same color. Each side therefore begins with one dark-squared bishop and one light-squared bishop. Other pieces do not share this general restriction.