Tokyo - Rugby World Cup referees' boss Alain Rolland warned that officials would be more rigorous than ever in penalising high tackles in Japan, shrugging off concerns that a rush of red cards could affect the tournament.
Rolland said on Monday that he was aware of fears that an excessive clampdown could "potentially have a negative impact" on rugby's global showpiece, with the possibility that red cards could decide the winner.
But Rolland said new guidelines aimed at preventing concussions were drawn up in collaboration with coaches, and that players should be well aware of the possible consequences of high shots.
When All Blacks lock Scott Barrett was sent off last month and banned for three weeks for a shoulder charge to the head of Wallabies skipper Michael Hooper, England coach Eddie Jones called the red card "ridiculous".
Jones, who claimed similar incidents went unpunished in England's pre-World Cup clash with France, appealed for "consistency and common sense" by referees. France lock Paul Gabrillagues, meanwhile received a six-week ban for a similar hit on Scotland's John Barclay although this was later reduced to three weeks on appeal.
While World Rugby's effort to minimise concussions has been to take a near zero-tolerance approach to blows to the head, Rolland said the framework for officials at the World Cup allowed for discretion.
He said referees needed to consider whether there was head contact, whether the degree of danger was high or low and whether there were any mitigating circumstances which could reduce the punishment from a red card to a yellow or just a penalty.
The television match officials (TMOs) have also been armed with the latest Hawk-Eye technology allowing them to zero in on trouble spots, and are also being encouraged to intervene when they see "serious acts of foul play where they can assist" officials on the ground.
But Rolland warned that if foul play produced a flurry of red and yellow cards, the problem would stem from the players and not officials.
"I'd be very confident that they (players) are aware of the high-tackle framework, and how it works," he said.
"We've made it very clear what the high-tackle framework is, how it operates but more importantly how it is there to protect them," Rolland added.