FIFA has confirmed that television replays to assist referees will be used for the first time in competitive action, with trials to take place during the Club World Cup in Japan, which kicks off on Thursday.
A number of semi-live tests were conducted during recent international friendly matches in Italy, but the video assistant referees (VARs) were not allowed to transmit information to referees.
VARs, who will be given access to all broadcast feeds inside a video operations room, will now be able to advise the on-field official of errors in "match-changing" situations.
The referee will then be able to review footage on a pitchside monitor for certain decisions, but he will continue to take the first as well as the final decision on the field of play.
"This represents a big step forward in terms of testing the technology," said Marco van Basten, FIFA's chief officer for technical development, ahead of the tournament in Yokohama and Osaka.
"At the same time it's important to remember that we are entering somewhat unchartered territory here, given that we are going live for the first time.
"Ultimately, these tests should prove invaluable in terms of determining whether the processes are sound or whether any further refinements are needed."
Live trials are due to take place from 2017 onwards in Australia, Belgium, Brazil, Czech Republic, France, Germany, Italy, Mexico, the Netherlands, Portugal, Qatar and the United States.
