Can I touch the net or step over the centre line?

Net contact (Rule 11.3 and 11.4):

• Touching the net between the antennae while playing the ball is a fault. "Playing the ball" includes take-off, the hit or attempted hit, and landing safely ready for the next action. A player close to the ball who is trying to play it counts as playing it, even without touching it.
• It is also a fault to use the net as a support, gain an unfair advantage by touching it, hinder an opponent's legitimate attempt to play the ball, or catch or hold the net.
• Touching the posts, ropes or the net outside the antennae is not a fault, as long as it doesn't interfere with play.
• If the ball is driven into the net and the net touches an opponent, that is not a fault.

Reaching over (Rule 11.1): a blocker may touch the ball beyond the net if they don't interfere with the opponent's play before the opponent's attack hit. After an attack hit, your hand may follow through over the net as long as the first contact was in your own space.

Centre line (Rule 11.2):

• Your foot may touch the opponent's court, as long as part of that foot stays on or directly above the centre line and you don't interfere with the opponent.
• A foot that goes completely into the opponent's court is a fault.
• Any other part of the body above the feet may touch the opponent's court, provided it doesn't interfere with play.
• You may go under the net into the opponent's space or free zone if you don't interfere, and you may enter their court once the ball is out of play.