What are the rules about the side-boards?

The side-boards form the long (44 m) sides of an indoor field, and the ball stays in play when it rebounds off them.

Trapping (Indoor Rule 9.14):

• Players must not trap or hold the ball against the side-boards.
• A player with the ball must not be trapped in a corner or against the boards by opponents with their sticks flat on the floor. Opponents must leave a reasonable outlet for the ball.
• If the ball gets unintentionally trapped between sticks or against the boards, play restarts with a bully.
• Repeated trapping against the boards is treated as intentional and penalised. So is deliberately trapping the ball between your stick and an opponent's to win a bully.
• FIH asks umpires to step in early when players use the corners or boards to shield the ball, especially late in matches.

Using the boards from a free push (13.2 e): from an attacking free push in your attacking half, the ball may enter the circle off the side-boards, as long as it travelled at least 3 m before rebounding.

Ball over the side-board (7.3): a free push to the other team within 1 m of where it crossed (or 1 m outside the circle and 1 m from the board, if it would otherwise be inside the circle).