Debate has swirled during the group stages of the World Cup after the introduction of the technology
Five controversial VAR moments in the World Cup so far
Like it or loathe it, there's been no avoiding the Video Assistant Referee during the opening weeks of the 2018 World Cup.
Many matches have had incidents which have required VAR, and resulted in correct decisions being made.
However, there's been occasions when it should have been used and wasn't, so the system has created great debate among fans and pundits as to whether it should be deemed a success.
Here are five key moments involving VAR so far:
This is what VAR was made for. Brazil were struggling to break down a solid Costa Rica when Brazil's golden boy, Neymar, felt a slight tug of his shirt inside the penalty area. The referee, who was only a few yards away, bought it and pointed to the spot. VAR was called upon and the truth was revealed – the impact on Neymar wouldn't have knocked over a toddler.
Life usually goes how Cristiano Ronaldo wants it to – and so it should with his talent and work ethic. But in Portugal's clash with Iran, he wasn't having one of his better days, having missed a penalty and struggled along with his teammates to see off their lower-ranked opponents. Then he gave chase to a ball over the top and flung an arm towards the head of Morteza Pouraliganji, who was attempting to hold him up. The Iranian fell to the floor and VAR deemed the offence worthy of a yellow card. Ronaldo either whacked him in the head or he didn't – red card or nothing.
Has the handball rule been changed? Because there was nothing deliberate in the way the ball connected with the arm of Portugal's Cedric near the end of their 1-1 draw with Portugal – the second crucial VAR moment in the match. A deep cross was swung over and Iran's Sardar Azmoun nodded it down via the arm of Cedric, who was mid-air at the time. VAR says review, referee reverses decision and says penalty. The more you watch it, the more ludicrous it gets. And if you are in the market for more ludicrous penalty decisions involving handballs, then take a look at the one awarded in the Saudi Arabia versus Egypt game, when the concept of "deliberate" was again completely absent.
Harry Kane wrestling match
The entire English nation and probably most of the rest of the world watching England versus Tunisia were left scratching their heads as to when wrestling became part of football. On two occasions, Harry Kane was practically body slammed to the ground as corners were swung over. Was VAR tuned in to WWE instead of the football? Everyone else saw it. And while we are on the subject of grappling in the penalty box, how did it miss the manhandling of Serbian man-mountain Aleksandar Mitrovic in the match with Switzerland, when he had not one, but two defenders bear-hugging him to the floor.
Swede and sour
Germany against Sweden was goalless when Sweden's UAE-based striker Marcus Berg raced through on goal with Jerome Boateng in hot pursuit. Berg was about the pull the trigger as he entered the penalty area and was the recipient of both a shove in the back and a trip as the chance to take the lead went begging. A quick replay cleared up the incident. Penalty. Was a penalty given? No.