Progressive chess

Progressive chess is a chess variant in which players, rather than making a single move on each turn, play progressively longer series of moves. The game starts with White making one move, then Black makes two consecutive moves, White replies with three, Black makes four, and the series keeps growing in the same way. Because a side can move several times in a row, the usual care about check has to be written into the rules, and different versions handle it differently: in the Italian version a check may be given only on the last move of a series, while in the Scottish version a check ends the series early. In both versions a player must escape check on the first move of a series. It is played by two sides, White and Black, on the ordinary chessboard.