A certain type of rugby fan gets very excited by the rolling maul, and for years collapsing it has led to an automatic penalty.

But the Stellenbosch laws allow the defending team to stop the maul's progress by dragging the whole thing to the floor.

"Some people will be horrified to hear this, but studies show it's not dangerous," said O'Brien.

"Although the maul is a great part of the game, one of the problems is how to stop it legally. So we're saying the defending side can collapse it."