Each team is allowed a maximum of three contacts with the ball before it must cross back over the net — a fourth touch is an immediate fault, awarding the rally to the opposing team. A block at the net does not count as one of these three touches, so a team that blocks an opponent's attack back onto its own side of the court still has a full three contacts available to build its own attack afterward, which is how extended rallies with repeated attacks stay legal.
The back-row attack rule restricts where a player who is currently positioned in the back row may legally hit a ball that is entirely above the height of the net. A back-row player may attack such a ball only while airborne from a takeoff that begins behind the three-meter attack line — the player may land in front of the line after contact, but the jump itself must originate from behind it. A back-row player who attacks a ball above net height while standing in front of the attack line, or who lands and takes off again inside it, commits a fault.
Why back-row attacks exist as a tactic at all
Because the restriction is about takeoff point rather than a ban on back-row hitting altogether, teams deliberately use legal back-row attacks — most famously the pipe attack, hit from the middle back position — as an offensive weapon that adds a fourth attacking option beyond the three front-row hitters, forcing the opposing block to defend a wider area of the net.
Remember: a ball below net height is exempt
One subtlety worth noting: the back-row attack restriction applies only to a ball that is entirely above the top of the net at the moment of contact. A back-row player standing in front of the attack line is free to play — and even attack — a ball that is below net height, since the rule is specifically concerned with a back-row player gaining an unfair net-level attacking advantage over the front row, not with restricting every kind of ball contact a back-row player might make near the net.
