Pawn promotion
Stockfish 16.1 · runs in your browserFirst drag the pawn from a7 to the empty b8 square. The board refuses a diagonal move without a capture. Then play a8=Q+.
Play on the board, or use Type a move below it.
Play a move by typing it, like e4, Nf3 or e7e8q, then press Enter.
Commentary
Move a piece, paste a position, or press the button.
Best move
A pawn reaching the last rank must become a queen, rook, bishop or knight of the same colour. It need not become a previously captured piece. The new piece takes effect immediately, so promotion can give check or checkmate.
Try the moves
Choose an example, play the suggested move, then reset to compare another legal move.
A pawn promotes when it moves to the farthest rank: White's eighth rank or Black's first. The pawn must become a queen, rook, bishop or knight of its own color as part of that move. You cannot leave it as a pawn, choose a king, or delay the choice until a later turn. The new piece takes effect immediately, so its arrival can give check. It does not have to replace a piece you lost earlier; a player may have more than one queen.
On both boards the white pawn stands on a7. First try dragging it diagonally from a7 to b8. That empty square offers no piece to capture, so the board refuses the pawn move. On the queen board, play a8=Q+ and inspect the queen giving check from a8. Reset and choose the knight example, a8=N. The two results start from the same position, yet the new pieces attack different squares. A knight promotion is called an underpromotion because it chooses a piece other than a queen.
Most players choose a queen because it usually offers the most power, but a knight's jump can create a check or tactic the queen cannot. Sometimes promoting to a stronger piece can leave the opponent with no legal move and no check, causing stalemate; choosing a rook or knight can avoid that in a suitable position. This board does not claim such a tactic here. When your pawn reaches the last rank in a real game, check captures on that square, your king's safety, and the immediate effect of each possible new piece before choosing.
Rules and examples
FIDE Laws of Chess, Articles 3.7.3.3 to 3.7.3.5, define the choice and its immediate effect.
Rules: FIDE Laws of Chess, effective 1 January 2023. https://handbook.fide.com/chapter/E012023
Rule replay: python-chess 1.11.2 (GPL-3.0-or-later). The shared browser engine retains its Stockfish GPL-3.0 notice. No engine score is claimed by these demonstrations.
Read the rulesA move on the board
7k/P7/8/8/8/8/8/4K3 w - - 0 1
Q6k/8/8/8/8/8/8/4K3 b - - 0 1
- a8=Q+The pawn reaches a8 and becomes a queen, giving check.
The pawn reaches a8 and becomes a queen, giving check.
Original teaching example replayed with python-chess 1.11.2, 2026-10-23.
Analysis runs on Stockfish 16.1 in your browser, compiled to WebAssembly by stockfish.js. Stockfish is free software under the GNU General Public License v3; its source code is on GitHub.