Verto

Verto is an abstract board game which can be played with a Reversi set (though a 9x9 board is recommended).

Players enter stones (with their own color facing up) on empty spaces. If a stone is placed such that exactly one opponent stone is orthogonally or diagonally between the entered stone and another friendly stone, then this opponent stone is flipped and becomes a friendly stone. Then the capturing stone becomes the new starting point for another capture move and so on ...

The player who ends up with the majority of stones on the completely filled board wins the game.