Which of the following actions is NOT allowed during net play?

Blocking a served ball is not allowed during net play because the primary purpose of blocking is to prevent an attack from the opposing team, generally occurring during regular rally play after a serve. The rules specify that any player may not attempt to block a serve, as this is considered a violation. Blocking is designed to counter attacks, not to interfere with a serve, which is a more controlled action that transitions into the rally phase of the game.

In contrast, recovering a ball hit into the net is permitted if the ball rebounds off the net and stays in play. This is part of normal play where players can attempt to keep the rally going. Contacting the ball on the opponent's side of the net is also allowed as long as it does not involve any form of interference or violation of the net rules. Additionally, a ball may contact the net and cross over to the other side, which is entirely permissible. The rules allow for these actions because they maintain the flow of the game and allow for strategic responses to plays.