Promotion is when a pawn reaches the last rank of the board (8th rank for White, 1st rank for Black) and is transformed into another piece.

Rules

• A pawn can be promoted to a queen, rook, bishop, or knight.
• It is usually promoted to a queen (the strongest piece).
• Underpromotion: Sometimes promoting to a knight instead of a queen can be more advantageous (for example, to create a knight fork).