What happens if the ball touches the antenna in volleyball?

If the ball contacts the antenna or passes outside the antenna, it is a fault. The opponent scores a point and gains the serve.

Full Explanation

Per FIVB Rule 2.3, the antennas are considered part of the net, and the ball must cross entirely within the two antennas (and their imaginary vertical extensions above the net). Per FIVB Rule 10.1.2, the ball is out when it contacts the antenna or passes to the opponent's court outside the antenna. The penalty is a point awarded to the opponent. This applies under FIVB, USAV, NFHS, and NCAA rules. The antennas also help line judges determine whether a ball crossing the net is in or out.

Rulesets covered: FIVB/USAV/NFHS/NCAA  |  Rule Reference: FIVB Rule 2.3; FIVB Rule 10.1.2