A different piece must be moved during each move. Pawns only move forward. Pawns in the light army move to the right. Pawns in the dark army travel to the left. En passant and promoting of pawns applies as in standard rules of chess.
Major pieces can move forward or backward.
However, the king must stay on his own board segment. If there is an opening, a queen or a rook or any other piece besides the king, can move around the entire playing field. If on the first move of a turn, an army puts an opponent's king in check. The team should finish their second turn, but cannot checkmate the king. The king that is in check must be taken care of immediately on the first move for that army.