A portable game board has a ring-shaped frame containing at least one slide panel marked with indicia used to score trajectories of playing disks slidably launched on the slide panel, which comprises a base panel, an optionally segmented game indicia panel placed on the base panel, or a transparent window slide panel. A pair of base panels having different game indicia are positionable back-to-back within the frame, and selectable by inverting the frame. The board is optionally supportable at an adjustable elevation angle, quantifiably increasing the energy required to propel a disk to distance markers on a panel. An optional platform rotatably supports the game board, facilitating access to board locations by a circle of players. Optionally, an indicia panel contains one or more recessed magnetic slugs; playing disks are provided with one or more ferromagnetic inserts which interact with the slugs to alter the trajectory of a disk.