The court and its lines
The playing court measures 18 × 9 m, divided into two 9 × 9 m halves by the centre line. The lines are 5 cm wide, of a light colour contrasting with the floor, and are drawn inside the dimensions of the court: the 18 × 9 measurement therefore includes the lines, and a ball touching a line is in.
The attack line, commonly called the "3-metre line", is drawn so that its rear edge is 3 m from the axis of the centre line. This is a detail that matters when marking a court: the reference is the centre of the centre line, not its edge. In FIVB competitions, the attack line is extended outwards with a dashed line to help referees judge back-row attacks.
The zones defined by the rules
- Front zone (or attack zone): between the axis of the centre line and the
rear edge of the attack line. This is where the restrictions on back-row players' attacks and on attacking the serve apply.
- Back zone: the rest of the court, up to the end line.
- Service zone: the 9 m wide area behind the end line,
delimited by two short lines drawn just behind the end line as an extension of the side lines. The server can move freely within this entire area, and in depth up to the limit of the free zone.
- Free zone: the space around the court, free from obstacles, of at least
3 m on each side. In FIVB competitions it is wider (5 m on the sides and 6,5 m at the ends).
- Free playing space: the height above the playing area, free from obstacles,
of at least 7 m from the floor (much more in FIVB competitions).
- Substitution zone: the part of the free zone in front of the scorer's
table, between the extensions of the two attack lines.
The crossing space
This is the concept that explains half of the arguments about "was it in or out". The ball must pass over the net within the crossing space, delimited below by the top edge of the net, on the sides by the antennae and their imaginary extension upwards, and above by the ceiling. A ball passing outside this space is out even if it lands back inside the opponent's court. It follows that a ball touching an antenna is always out, and that a very wide ball can be recovered and played back from the side it went out, if it has not yet crossed the plane of the net outside the crossing space.
When the sports hall is non-regulation
Most amateur sports halls have at least one issue: low ceiling, a free zone of one and a half metres, basketball hoops over the court, close walls. You cannot change the building, but you can write house rules. The three most useful:
- Ceiling and hoops. In the official rules, a ball touching the ceiling is
out. If the ceiling is low, many amateur events allow a ball that touches it above one's own half of the court and falls back into one's own half, and consider everything else out. Also specify what happens if the ball touches a hoop or its structure.
- Insufficient free zone. If the wall is one metre from the end line,
the criterion is safety: declare that the rally is stopped when a player risks an impact and the point is replayed. It is less "sporting" than a heroic dive and saves you a trip to A&E.
- Reduced court. If space does not allow for 18 × 9, draw a shorter
court symmetrically and keep the 3-metre line proportional. Better a declaredly reduced court than a crooked one.
One last detail regarding multi-use sports halls: when there are basketball, futsal and volleyball lines on the floor, state at the start of the tournament which colour counts. It is the kind of misunderstanding that costs a set halfway through the day.