Standard 8×8 board. White moves first. Checkmate to win.
Castling: King moves 2 squares toward rook if neither has moved, no pieces between, king not in/through check.
En Passant: Capture a pawn that just moved 2 squares past your pawn as if it moved 1.
Board: 91 hexagons, 3 colors (no same colors touch).
Pawns (9): Forward 1, capture diagonal-forward. Double move first turn. Promote at far edge.
Rooks: 6 straight directions through adjacent hexes.
Knights: 2 straight + 1 sideways = 12 destinations!
Bishops (3): Diagonal = same color only. One bishop per color.
Queen: Rook + Bishop. Extremely powerful!
King: 1 step any direction (12 moves including diagonal).
Special: No castling. Stalemate = 3/4 win.
Hex variant by Władysław Gliński (1936), popularized by CGP Grey.