Touch-move rule move or capture the first of the pieces that they touched. If it cannot be determined whether he touched his own piece or the opponent's piece first, it is assumed that he touched his own piece first. If a player touches more than one piece, he must move or capture the first piece that can be legally moved or captured. An exception to that is an attempted illegal castling; in that case the king must be moved if possible, but otherwise there is no requirement to move the rook. When castling, the king must be the first piece touched. If
Martian chess players decide who moves first. Play turns alternate, and pass to the left after each move. The red lines in the diagrams indicate notional "canals" which divide the board into "territories", or quadrant. At any given time a player controls only those pieces that are in his or her territory. The pieces move as follows: As in chess, a square may contain no more than one piece, and a piece is captured when an enemy piece lands on the square it occupies. The capturing player removes the piece and puts it aside for later scoring. In the two-player game, a