Chess
Board Games · 9 specs
Direct Answer
Chess is a two-player abstract strategy board game governed internationally by FIDE (Fédération Internationale des Échecs). Standard laws define 64-square alternating boards (50–60 mm squares), exact piece movements, en passant capture timing (Article 3.7), castling restrictions (Article 3.8), and draw criteria including the 50-move rule and threefold repetition.
Source: FIDE Laws of Chess 2023 (Handbook E.01) · Last reviewed Aug 28, 2026
Specs
| Governing Body | FIDE (World Chess Federation) |
| Board Grid Dimensions | 8 × 8 (64 alternating squares) |
| Tournament Square Size | 50 to 60 (2.0 to 2.36 inches) mm |
| Standard King Height | 95 (3.75 inches) mm (±5 mm tolerance) |
| King Base-to-Height Ratio | 40% to 50% of piece height |
| En Passant Execution Window | Immediately on the next move only FIDE Art. 3.7.4.2 |
| 50-Move Draw Rule | 50 consecutive moves without pawn move or capture FIDE Art. 9.3 |
| Threefold Repetition | Same exact board position occurs 3 times FIDE Art. 9.2 |
| Dead Position Rule | No sequence of legal moves can lead to checkmate FIDE Art. 5.2.2 (Instant Draw) |
En Passant: The Exact Mechanic & Window
When a pawn advances two squares from its starting position and lands adjacent to an enemy pawn on the same rank, the opponent may capture that pawn 'en passant' (in passing):
- The enemy pawn moves diagonally forward to the square the passed pawn skipped over.
- The passed pawn is removed from the board.
- Strict Timing Rule (FIDE Art. 3.7.4.2): En passant can ONLY be executed on the immediate next turn. If the player makes any other move, the right to capture that pawn en passant is permanently lost.
Castling Restrictions (Article 3.8)
Castling is a simultaneous move of King and Rook, moving the King two squares toward the Rook and placing the Rook on the square the King skipped over. Castling is strictly illegal if:
- The King has previously moved in the game.
- The specific Rook has previously moved.
- The King is currently in Check.
- The King must pass through or land on any square attacked by an enemy piece.
- Any pieces stand between the King and Rook. (Note: The Rook CAN be under attack, and the King's Rook can pass through an attacked square on queenside castling, provided the King itself does not cross an attacked square).
Draw Conditions: Stalemate, 50-Move, & Repetition
- Stalemate: The player whose turn it is has NO legal moves and their King is NOT in check. The game ends immediately in a draw (half point each).
- Threefold Repetition (Art. 9.2): A player may claim a draw if the identical board position (including castling and en passant rights) appears three times with the same player to move.
- 50-Move Rule (Art. 9.3): A player may claim a draw if 50 consecutive full moves (50 White, 50 Black) pass with zero pawn moves and zero captures.
- Insufficient Material (Dead Position): King vs. King; King + Knight vs. King; King + Bishop vs. King.