The playing field is a carpeted, rectangular area. Dividing the field in half is an 18 in (457 mm) high railing with a central bridge, which can tilt to either side of the field or remain level. Two 7 ft (2 m) high movable goals begin on opposite sides of the field. Around the perimeter of the field are two stations for human players, who work with remote controlled robots on the field to score points. At the start of each match, the alliance station contains twenty small balls. An additional twenty small balls and four large balls are located at the far end of the playing field.