In the first stage stones are dropped on the board, two by two. The central square must be left empty. When all stones are dropped they may move one step orthogonally in all directions. An enemy stone is captured by surrounding the stone with two of one's own, either horizontally or vertically (so called interception-capture or custodian capture). If the piece with which one began capture has more possibilities of capture then one may continue capturing. Win is achieved by capturing all (or a majority) of the opponent's pieces.