To provide a projected beam discrimination device capable of discriminating plural beams speedily at low cost.

A beam point P1 of a laser beam gun used by one player has a triangular pattern comprising three upwardly sharpened light spots OP, and a beam point P2 of a laser beam gun used by the other player has an overturned triangular pattern having three light spots OP. Since the patterns of the beam points P1 and P2 of the two laser guns are different from each other, each beam can be discriminated by image processing to video signals photographing the beam points P1 and P2.