|RBS Six Nations: Wales v England|
|Venue: Millennium Stadium, Cardiff Date: Friday, 6 February Kick-off: 20:05 GMT Coverage: Live on BBC TV, HD, Red Button, Radio 5 live, BBC Radio Wales, Radio Cymru, the BBC Sport website, S4C online, tablets, mobiles, the BBC Sport app and Connected TVs|
|Click here for full details of BBC's Six Nations coverage|
Wales defence coach Shaun Edwards says England risk being penalised if they use their 'league' tactics in Friday's Six Nations opener in Cardiff.
Former Great Britain rugby league captain Edwards claims England use illegal rugby league-style plays.
He says Stuart Lancaster's side employ blocking runners ahead of the ball carrier.
"It is a risk doing a lot of those league plays because of the obstruction rule," said Edwards.
Edwards made 467 appearances for Wigan, scoring 226 tries for them between 1983 and 1997 and winning 36 caps for Great Britain in league.
He says the Welsh defence must be aware of such tactics going in to the opening game of the tournament.
"It is important we get our structure right on that," said Edwards.
"It is also important there is no obstruction of our defensive plays up ahead of the ball.
"When you watch rugby league games, there are a lot of tries disallowed when they go to the TMO [television match official] if there has been any obstruction ahead of the ball.
"I am sure the TMO and the referee will be well aware of that."
French referee Jerome Garces will be in charge of Friday's contest at the Millennium Stadium.
England attacking skills coach Mike Catt responded to Edwards' claim that the visitors use "league plays" by pointing out that Garces will have the final say.
"Obstruction is a standard rule in the game. If you are obstructing someone you get penalised," Catt said.
"And you now have the third referee as well who decides whether a try has been scored or if someone has been taken out."
Shaun Edwards, meanwhile, believes Wales and England could kick more because the Millennium Stadium roof will be open for Friday's game.
Both teams must agree for it to be closed and while Wales head coach Warren Gatland stated that was his preference, England have declined.
Edwards thinks dew on the grass will make the conditions difficult.
"Teams might kick more than they would do with the roof closed," said the Wales defence coach.
"The grass can get a little bit slippy out there. We've just been out there today with the roof open and there's no doubt it is wetter than it was, say, in the autumn series."
However, Edward does not believe the decision will have a major affect on the atmosphere.
"It's within the rules of the Six Nations so we just have to get on with it and abide by it," he said.
|Wales' Six Nations fixtures:|
|Friday, 6 February: England (Cardiff)|
|Sunday, 15 February: Scotland (Murrayfield)|
|Saturday, 28 February: France (Paris)|
|Saturday, 14 March: Ireland (Cardiff)|
|Saturday, 21 March: Italy (Rome)|
"It's not something we've discussed here much. I believe it's going to be a dry night so hopefully it's a good game of rugby.
"In any Wales v England game there's going to be a lot of atmosphere - obviously it does resound a little bit more when the roof's closed - but it's still going to be a tremendous atmosphere."