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
Three-player chess avoid this "petty diplomacy" problem by determining the victor as the player who first delivers checkmate, with the third player losing in addition to the checkmated player. Other solutions have been tried as well. Some variants use a board with hexagonal cells. Usually three bishops per side are included, to cover all cells of the hex playing field. Pieces move usually as in one of the versions of hexagonal chess. Some variants use a hexagonal-shaped board with quadrilateral cells (see example in the photo). Some variants have used other board shapes with quadrilateral cells. Triangular cells not on the perimeter