An Othello variant. The players play on an orthogonal board. Also, the rules differ in that when opponent's stones are turned over, the line formed by your two stones may contain empty spaces as well.
White starts with one piece in the center. Then any space may be chosen. The board contains a 7 x 7 grid without the corners and the 2 spaces nearby, which gives 37 spaces for the 37 doublesided pieces.