The chaos of the ruck: What the heck is actually going on in a rugby pile?

The truth behind Rugby's greatest weapon (1:41)

ESPN investigates what a ruck is -- it's far from a mad scramble akin to the fight for a fumble in the NFL -- and how it should be orchestrated. (1:41)

Physical. Intense. Mysterious. A "bundle."

These are just a few of the words used to describe a rugby ruck, the moment in the game where bodies from both teams pile on top of each other and the ball becomes almost incidental, seemingly lost for good.

But far from it being a mad scramble akin to the fight for a fumble in the NFL, there is a structure to it, heaps of technique involved and no shortage of regulations about what a ruck is and how it should be orchestrated. Oh, and there's plenty of room for the dark arts as well, of course.

We asked players at Harlequins, the English Premiership club based in west London, to shed some light on the chaos for the uninitiated...

OK, guys, explain the ruck...

"When a tackle is made, you have two guys on the floor: the tackler and the ball carrier," says Max Crumpton, who plays hooker (the No. 2 jersey) for Quins. "Then you have the defensive player trying to get the ball. Then, the attacking team will try and secure the ball, and that's done over the two people on the floor. Once that's done, that's the ruck formed."

So how many people end up in a ruck, then?

Will Collier, a prop who has featured twice at the international level for England, explains: "You get the front row (Nos. 1, 2 and 3) and then there's the No. 4 and No. 5 in the second row, the really tall lads, they're primarily the guys you want to be 'blasting out' the ruck." And on the defensive side of the ball? "The back row -- Nos. 6, 7 and 8 -- they're the quite quick guys, who are really menacing, so they're the lads who get over the ball and try and win it back for the defence."

Got it. So what's the aim for the attacking team?

"A good attacking ruck is getting the ball back quickly for the scrum half (No. 9) to play the ball away as fast as possible, get the attack going and not let the defence settle," says Will Evans, a flanker who joined Harlequins from Leicester in the summer. "From the defensive point of view, you've got your back-row, No. 7, he's the best at retrieving the ball at the ruck and he's trying to get his hands on the ball."

Sounds simple enough. It's very physical, though -- is it safe?

"Yeah, there's a lot of things that you can't do in a ruck," adds Crumpton. "So for example, you can't come in from the side and take someone out, so when you're getting into contact, everything has to be front on. You get the odd occasion where someone will come in from the side but that's generally a penalty. When you're defending, you've got the opportunity to go for the ball so it's all safe, there's nothing wrong with it really."

"It can be a little bit of a mess if there are multiple players going for the ball," says Tom Lawday, the No. 8 who joined from Exeter earlier this year. "It's up to the referee's interpretation as to what is actually going on."

Ah, so this is where the dark arts come in?

"There's a few bits and bobs," laughs James Chisholm, who plays in the back row. "It's a big opportunity to impose yourself physically. There's a few tricks to try and win position for a slighter guy -- dark arts is probably a good phrase for it."

"We've actually been doing a bit of jiu-jitsu," adds Collier. "I think that's meant to be a secret, but anyway... So if you're coming in late and you've got the defender who's already over the ball, you've got to try and get him off somehow. You haven't got momentum and you're trying to put your body weight on top of him, you try and grab his shoulder as you can't grab the neck. You want to try and flip them over but try and make it look as legal as possible."

And there are rules against this?

"They've brought in regulations so you're not allowed to do anything on the neck now, which is good," says Collier. "They're really protecting the neck so you're not allowed to jump on a player or roll them off [the pile] by the neck. Back in the day, it was everyone flying in and smashing heads."

That can't be good for anyone. What's the worst that can happen?

"The worst possible scenario is if you've got a couple of the big boys jackaling for the ball, and you smash into them and they just don't move!" says Lawday.

"When we played Bath [in 2017], I didn't clear a guy out properly and it led to me being sent off," admits Chisholm. "It's really important to clear people out safely."

Collier adds: "[One time] I went into the ruck, I missed it. There was a little pothole, I went in, rolled my ankle and had to go off injured."

Guys, is it really worth it?!

"The best experience is when someone's over the ball and you fly into it and you take them out and you turn the ball over," says Crumpton. "That's really a good experience when you know you've hit someone hard, you've knocked them back and it's almost like a man test. It's a good feeling."