The aim of the up and under kick is to try and kick underneath the ball and to get as much height as possible. The ball should rotate end over end and allow your players as much time as possible to get underneath it.
Explanation: Kicking in rugby can be used as a defensive or an attacking tactic, depending on the situation. It is a good way to clear the danger if the team are under pressure. However with a good kick over the top of the opposition they can be the team under pressure.