The revised scrum engagement process will be trialled alongside the five law amendments announced in May, from the start of the next season in each Hemisphere and forms one part of the IRB's ongoing commitment to improving the scrum phase of the game.
The sequence will see the front rows crouch then touch and using their outside arm each prop touches the point of the opposing prop's outside shoulder.
The props then withdraw their arms. The referee will then call 'set' when the front rows are ready. The front rows may then set the scrum.
This sequence was one of six that were extensively researched at six different levels of the game, including women's rugby, as part of the initial trial process. 'Crouch, touch, set' was found to be the most successful and will now be trialled on a global level.
IRB Rugby Committee Chairman and former New Zealand captain Graham Mourie said: "Most people accept the scrum is currently a problematic area of the game, accounting for roughly 17% of match time in elite rugby and with more than 50% of scrums resulting in collapses or resets.
"The IRB is committed to addressing these issues and has tasked the specialist steering group to identify the causes and solutions.
"This is a positive first step, but it should be noted that we must wait for the outcomes of the three-year Scrum Forces Project before we can take an holistic approach to the scrum."
IRB Chairman Bernard Lapasset said: "The scrum is a complex, dynamic area and it was very clear from the advice and expertise evaluated by the Scrum Steering Group that there is no quick and easy fix.
"There are many contributing factors and we need to take a complete view of the scrum environment including engagement, laws, forces and player welfare.
"I would like to thank all Unions for their continued commitment to the important process of improvement in this area and their full support of this initial trial. I would also like to thank the RFU for their ongoing support of the Scrum Forces Project in Bath."
David Barnes, the International Rugby Players' Association (IRPA) representative on the Scrum Steering Group and Rugby Players' Association (RPA) Rugby Manager, commented: "The number of scrum resets in the elite game has reached an unprecedented level and the new three-step process is a significant advance in trying to address the issue.
"As the IRPA player representative on the Scrum Steering Group, players will have input to any potential changes being considered.
Didier Retière, France's 2011 Rugby World Cup forwards coach, current France Under-20 coach and Scrum Steering Group member, remarked: "As coaches and players we have a collective responsibility to buy in to this process and work together to address issues at scrum time."
Graham Rowntree, RFU forwards coach, added: "We need to have less collapses and resets and anything that can improve this vital part of our game should be applauded. I will be very interested to see how the trial goes."
The revised sequence has yielded positive outcomes and it should be noted that the sequence is just one area of the scrum that is being reviewed by the IRB and its member Unions.
The Group examined the results of extensive testing of engagement sequence variations in live and machine environments in a trial driven by the IRB Scrum Forces Project which provides in-depth analysis of biomechanical forces in the scrum.
The unprecedented IRB-funded three-year study is being run by the Sport, Health & Exercise Science group at the University of Bath in collaboration with the RFU and is intended to identify better playing, coaching and refereeing techniques for this key facet of the game.
Leading experts from the coaching, medical and scientific fields are driving the two-phase study which has involved the whole spectrum of the rugby playing population, from men's and women's international and elite professional teams to university, community club and school level.
Phase one, set against a machine environment, has been completed and phase two which will holistically examine forces in contested live scrums, is already underway with the RFU assisting in providing suitable clubs and teams from the Aviva Premiership to the community level to assist the study.
While the 'crouch, touch, set' sequence has been selected for global trial, two other sequences will continue to be examined as part of the University of Bath research project.
The outcomes of the Scrum Forces Project phase one have been presented to the IRB Rugby Committee and Scrum Steering Group for consideration. Phase two results will be presented during 2012 and early 2013.
Scrum Steering Group -
David Barnes (IRPA), Mike Cron (NZRU), Didier Retière (FFR), Brian O'Shea (ARU), Norm Mottram (USA Rugby), Richie Dixon (GRU), Ken Quarrie (NZRU), Graham Mourie (Chairman of IRB Rugby Committee), John Jeffrey (IRB Council Member & SRU), Gavin Williams (RFU), Dr Martin Raftery (IRB Chief Medical Officer), Paddy O'Brien (IRB Referee Manager).
Scrum Forces Project Group -
The members of the Scrum Steering Group plus Keith Stokes (University of Bath), Dr Mike England (RFU), Colin Fuller (IRB Risk Management Consultant), Grant Trewartha (University of Bath), Ezio Preatoni (University of Bath).