One is not allowed to just go charging into an opponent who doesn't have the ball, but there would definitely be an advantage in using as much force as possible when initiating physical contact with one's opponents when forming a ruck, so how is the line drawn?One is not allowed to just go charging into an opponent who doesn't have the ball, but there would definitely be an advantage in using as much force as possible when initiating physical contact with one's opponents when forming a ruck, so how is the line drawn?

Your premise is flawed. Come through the gate, keep your shoulders above your hips, and make some minimal attempt to bind with your opponent, and you can come in as hard as you like. That said, if you do this each and every time you enter a ruck you are not going to make it through the game. I guess the line would be drawn at "common sense".

Must come from behind the last feet Don't hit anyone in the head Shoulders higher than hips (or you will go off your feet and be penalised) Other than that you can pretty much go for it

Andrew is right on. As long as you follow the rules you can come in as hard as you want.

As long as you follow the rules of the ruck, there is no restrictions on the force used. You have to stay on your feet, and your shoulders must stay about your head, for a start. You cannot punch, slap, kick, etc. You can only clean out using your shoulders and arms, using leg drive. You can't dive over/ontop of the ruck, because not only does it seal off the ball, but it is just plain dangerous. You also can't collapse a ruck/maul. You must drive other plays backwards, not off of their feet. Obviously if they slip, you shouldn't be penalised. That covers the main parts, but there's many more nitty gritty rules which often aren't applied as much as these ones. Hope I helped.