Abstract: The present invention relates to an adjustment mechanism for game boards that allows a user to correct for warp to the playing surface due to changes in climatic conditions. The adjustment mechanism includes at least two adjusting members mounted in a transversely spaced arrangement to the underside of a game board and connecting member engaging the adjusting members through threaded connections. Through rotation, the connecting member exerts a force to drive the adjusting members away from or toward one another thereby impacting the degree of concavity imparted to the playing surface. Rotating the connecting member in one direction increases the concavity of the playing surface and rotating the connecting member in the opposite direction reduces the concavity of the playing surface. The connecting member includes a polygonal portion for engagement with a tool allowing the user to adjust the concavity of the playing surface in a single motion.