LONDON • Fifa president Gianni Infantino on Friday confirmed that for the first time, Video Assistant Referees (VARs) will be used at the June 14-July 15 World Cup Finals.
But there was an intriguing subplot to the announcement, with teams permitted to use a fourth substitute in matches that go into extra time.
The use of the VAR system was approved earlier this month by football's rule-making body, the International Football Association Board (Ifab).
This was despite the controversy over the time taken to make decisions and the lack of information for spectators in major European leagues like Italy's Serie A and the German Bundesliga, where it has been trialled.
"We are going to have our first World Cup with video assisted refereeing," Infantino told reporters after a meeting of the Fifa council.
"It's an essential decision, very important and historical decision."
The system allows the referee or the video assistant to review decisions where a "clear and obvious" error is spotted.
Infantino said VAR had been shown to reduce the number of refereeing mistakes in matches where it has been used and would help football become "a fairer and more transparent sport".
"It's not possible that, in 2018, everyone in the stadium and their living room knows if a referee has made a big mistake or not, and the only one who doesn't know is the referee," he added.
Fifa also said that Ifab had approved the rule change enabling teams to make a fourth change for games that go into extra time in the Finals in Russia.