What is the attack line in volleyball and who can cross it?

The attack line (3-meter line) divides the front zone from the back zone. Front-row players may attack and block anywhere. Back-row players may only complete attacks above net height if they take off from behind the line.

Full Explanation

Per FIVB Rule 1.3.3, the attack line is drawn 3 meters from the center line on each side, dividing the court into front zone and back zone. Front-row players (positions 2, 3, 4) may attack and block from anywhere in the front zone or behind the attack line. Back-row players (positions 1, 5, 6) may only complete an attack hit above net height if their takeoff was from behind the 3-meter line (FIVB Rule 13.3.2). A back-row player may land in front of the line after a legal takeoff. The attack line also marks the boundary for the libero replacement zone. Any player may cross the attack line at any time -- the rule governs takeoff point for attacks only.

Rulesets covered: FIVB/USAV/NFHS/NCAA  |  Rule Reference: FIVB Rule 1.3.3; FIVB Rule 13.3.2