5. Rules of Play
How the Pieces Move
- Bishop: any number of squares along a diagonal, without leaping over another piece (Art. 3.2)
- Rook: any number of squares along a rank or file, without leaping (Art. 3.3)
- Queen: any number of squares along a rank, file, or diagonal, without leaping (Art. 3.4)
- Knight: an L-shape - two squares in one direction then one perpendicular - and may jump over pieces (Art. 3.6)
- King: one square in any direction (Art. 3.8.1), plus castling (below)
Pawn Moves (Art. 3.7)
- Advances one square forward to an unoccupied square (Art. 3.7.1)
- On its first move it may advance two squares, provided both are unoccupied (Art. 3.7.2)
- Captures diagonally forward one square only (Art. 3.7.3)
- En passant: a pawn may capture an opponent's pawn that has just advanced two squares, as if it had advanced only one (Art. 3.7.3.1-3.7.3.2)
- Promotion: on reaching the far rank the pawn must be exchanged, as part of the same move, for a queen, rook, bishop, or knight of the same colour (Art. 3.7.3.3-3.7.3.5)
Castling (Art. 3.8.2)
- The king moves two squares toward a rook, and that rook moves to the square the king crossed
- The right is lost permanently if the king or that rook has previously moved (Art. 3.8.2.1)
- Castling is prevented if the king is in check, or would cross or land on an attacked square, or if pieces stand between king and rook (Art. 3.8.2.2)
Check and Legality
- A king is in check when attacked by one or more enemy pieces (Art. 3.9.1)
- No move may leave or place a player's own king in check (Art. 3.9.2)
Touch-Move (Art. 4)
- Saying "j'adoube" / "I adjust" before touching allows a player to adjust pieces without being obliged to move them (Art. 4.2.1)
- Otherwise, touching a piece obliges the player to move or capture it if a legal move exists (Art. 4.3)
- Touching king then rook obliges castling if legal; touching the rook first forbids castling with that rook this move (Art. 4.4)
- The choice of promotion piece is final once that piece touches the promotion square (Art. 4.4.4)
- A piece released on a square cannot be moved again on that move (Art. 4.7)