A setter's duty is to control the offense, set up kills, create plays with the attackers and dupe the other team's blockers. It's important to know what plays by the setter are deemed illegal by the referee.
A setter can be called on the following by the referee:
- A double: If the ball spins over a certain number of rotations during its trajectory.
- An "over" call: If the setter makes contact with the ball if it's broken the plane of the net
- An "under" call: If the setter's foot crosses under the midline beneath the net and causes a safety issue with the other team, or if they cross the midline and make contact with an opposing player.