This is one of the methods used to restart play when the ball has gone over a team's dead ball line.
For example, if the attacking team kicks the ball beyond the dead ball line, a member of the defending team can touch it down for a 22-metre drop-out.
The defending team can also ground the ball in their in-goal area for a drop-out if a player on the other side was the last person to touch the ball.
Once the ball has been touched down, a player from the defending team can advance to the 22m line and restart play with a drop kick.
They can kick the ball a short distance forward and try to regain possession, put up a high kick for the forwards to get under or kick the ball as far as possible down the field.
A 22-metre drop-out is not awarded, however, if a member of the defending team has either passed or carried the ball back over the dead ball line before the ball is touched down.