Compact Chess Compact chess was invented by the Cowplay Team at the birth of the website. The setup, as shown in Figure 1, places standard pieces on a 6x6 board with central pawns being replaced with the bishops. Compact Chess Setup Figure 1 Rules All standard chess rules apply to this variant, including en-passant, pawn's 2-square advance and promotion. Castling Variation Only queenside castling is available in Compact Chess because of the kings single-square movement on the kingside. For example, white's only castling option (queenside) will leave the white king on b1 and the white rook formerly on a1 moved to c1.