On Guard is played on a 7x7 square grid of raised circles on which the circular, stackable playing pieces rest. Two players each of have 24 pieces of either yellow or orange, and begin the game by taking turns placing their single pieces (Guards) anywhere on the board but for the center circle. Each player on his first turn must create an Officer by moving one of his Guards onto another. Guards may move horizontally or vertically to the next adjacent vacant space, and may not jump or capture. Officers may move any number of (unobstructed) spaces horizontally or vertically, even making 90 degree turns, and may jump and eliminate other Officers, but not Guards. Only one Office can be made per turn. To win the game, capture all the opponent's Officers, or block him from moving any remaining pieces.