A horse racing game apparatus for simulating horse races has a game board with race courses established thereon and a plurality of simulated racehorses movable along the race courses for ranks. A central field is disposed on the game board and defines an inner circumferential path for the race courses. The central field is selectively extensible and contractable in at least one direction. The horse racing game apparatus also has a start gate for indicating a start position for the race courses. The start gate is disposed so as to be movable along the race courses. The start gate is angularly movable between a first position in which it lies over and across the race courses and a second position in which it is retracted away from the race courses.