SWOT Chess

The major properties of SWOT are the following.

1) The board is 8 squares long by 8 squares wide. There are 6 squares marked with any symbols and 58 unmarked squares. The positions of squares are changeable
2) Each player chooses 16 of 48 pieces, consisting of 1 King, 1 Queen, 2 Bishops, 2 Horses, 2 Rooks, and 8 Pawns.
3) There are millions ways for setting up the board and pieces.
4) A player may elect to substitute a playing piece instead of moving a piece twice during the game.
5) The King may check another King in some manner.