A drop-goal is scored when a player kicks the ball from hand through the opposition's goal posts.
The ball is dropped to the ground and is kicked just after it has bounced - it can be a tricky skill to master.
If a team is awarded a free-kick, a drop-goal cannot be scored until
the ball next becomes dead
an opponent has played or touched it
an opponent has tackled the ball-carrier
This restriction applies also to a scrum taken instead of a free-kick.
A team will usually have a specialist drop-goal kicker and certain set plays they can call on to set up the best chance of a drop-goal.
It can be a very useful weapon to employ near the end of a game when the scores are tight.
Jonny Wilkinson scored in this way when England beat Australia in the World Cup final in 2003.