Standard chess on an 8x8 board. White moves first. All standard rules apply: Castling (king and rook swap, neither may have moved, king may not pass through check); En passant (capture a pawn that just double-pushed, available only on the next move); Promotion (pawn reaching the back rank promotes to Q, R, B, or N). Draws by stalemate, 50-move rule, threefold repetition, or insufficient material. Checkmate the enemy king to win.