The phaser range was a facility aboard some starships that allowed Starfleet personnel to practice aiming and firing their phasers. It consisted of a circular stage set in a large empty area. The area around the stage was illuminated, but everywhere else was dark. Flashing spheres of light of different colors and moving at various speeds served as the targets. Two people could be accommodated in the range at any one time. (TNG: "A Matter Of Honor" , "Redemption" )