At first glance this early Knizia title may seem like an easy version of 'Connect Four'. However, in Complica, when a piece is placed, it does not remain there for the entire game. Another piece may be used to slide the entire row over. Winner is first person to have 4 pieces in a row. The mechanic of the sliding rows means that each player can possibly have 4 in a row at the same time, causing the game to continue until this situation can be broken up.Online Play Super Duper Games - BoardGameGeek