Video: SportsJOE shows the infringements to look out for in this weekend's scrum action
Even when people play by the rules, the scrum can be a high pressure environment.
But when players take the rules into their own hands, things can get very, very dangerous.
Here at SportsJOE we see the scrum as one of the most important areas of the game, and so we're bringing you indepth previews and reviews of Ireland's scrum, and their opposition.
A number of trends have emerged over the first few rounds of Six Nations action at the setpiece, with referees being fooled and a lot of confusion surrounding some of the calls being made at scrum time.
With that in mind, we traveled down to Trinity College, to do a video demonstration with the Dublin University under 20s side, showing just what you should look out for over the coming weeks.
In the first of three videos, we're taking a close look at the effects a tighthead prop's illegal bind can have on the scrum, while we've also looked at how you can spot when a loosehead prop angles in on his opponent, to drive him illegally into the air.