Thirty years after Argentina's Diego Maradona infamously used his hand to score one of the two goals that knocked England out of the 1986 World Cup quarter-finals, the hand came into play again, this time in the 2016 Copa America Centenario on Sunday. Peru's Raul Ruidiaz netted the only goal in a match that Brazil needed only to draw to progress, and replays showed the ball struck his hand before going in.

Uruguayan referee Andres Cunha did not see it. Nor did the linesman. And the goal was awarded. The other players did, though, and, more importantly, so did the TV cameras.

The furious Brazilians protested and play was stopped for almost five minutes as the match officials discussed it with one another, but eventually the referee stood by his decision according to the laws of the game, which currently bar him from changing his mind after looking at video replays.

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This wasn't the first instance of a "Hand of god" goal in a high-stakes match since Maradona's original. In the 2010 World Cup qualifying playoffs, France's Thierry Henry handled the ball before scoring a goal that denied Ireland a spot in the finals. Henry even admitted to it after the match, but nothing was done to reverse the result. Fifa set up a committee to investigate the case against Henry, but eventually no action was taken.

Several calls to introduce technology to assist referees in reversing howlers were turned away, until 2012, when the International Football Association Board, which governs the laws of the game, decided to introduce goal-line technology to help officials determine whether the ball has crossed the goal line. Since then, there have been an increasing number of requests from football associations around the world to introduce video replays as well.

Finally, in March 2016, the IFAB took the plunge at its annual general meeting. It decided to introduce live experiments with video assistant referees, or VARs, in football, while also revising 94 laws of the game.

Here then are the questions that matter, and the answers.

So who is a video assistant referee?
It's a referee who will have access to video replays during the match. They can review an incident after being asked to by the on-field referee, or step in themselves if the on-field person misses something.

Will this referee be on the sidelines like the fourth official or somewhere else?
This hasn't been specified, but both possibilities have been discussed. The VAR is likely not to be on the sidelines, but in a room somewhere in the stadium with multiple screens in front of them. But they could also be on the sidelines with a tablet.

When can the video referee be called in or step in?
The IFAB has approved four "game-changing" scenarios when the video referee can come in: when a goal is scored, when a penalty is given, when a player is sent off, and when there is a case of mistaken identity. The video referee cannot come in for any other scenario, such as an offside decision or fouls, for instance.

Are these really the only game-changing scenarios?
It's definitely not foolproof. For example, there cannot be any review if a penalty is not given, or if a yellow card is given instead of a red.

Okay, but at least it's a step in the right direction?
It would seem so.

Will these referrals not slow down the game?
It's possible, but then when there is a really contentious decision, a lot of time is wasted as it is. A case in point is the Brazil-Peru incident, where at least five minutes were wasted. If anything, a video review would have sped up things. An official of the Dutch football federation, which is taking part in the trials, said that on average a review took about 12 seconds to complete.

Wow, that's quick! So, when can we expect to see this being implemented?
There's still some time to go, unfortunately. The IFAB wants to conduct experiments for at least two years in order to identify the advantages, disadvantages and any discrepancies. There will be a pre-testing "offline" phase, where VARs can familiarise themselves with the technology during live matches, but cannot interfere and communicate with the referee. This will be followed by "live" experiments, where the VARs will communicate with the referees. This is expected to start only in 2017.

Okay, and are all football matches and leagues part of this?
Nope. It is being tried only in the following countries and competitions:

Germany: Bundesliga.

United States: Major League Soccer.

Australia: A-League.

Portugal: Portuguese Cup, Super Cup and the Taca CTT.

Brazil: Several competitions under the umbrella of the country's football federation.

Netherlands: Several competitions under the umbrella of the country's football federation.

So, no EPL or La Liga or Serie A, and definitely not the international competitions just yet.

How much does the technology cost? Is it very expensive?
It's cheaper than goal-line technology, according to the Daily Mail. It's cheap because it can use the same equipment that the broadcasters are using. You just need to install the software on computers.

Okay, so when can we realistically expect it to be implemented across the football world?
The trials, beginning in August 2016, will go on for two years. The IFAB said the earliest a decision can be taken is 2018, and latest is 2019.

Is the 2018 World Cup a realistic possibility?
It's possible, but don't count on it.

Is there a possibility that the experiments will fail and the technology won't be implemented at all?
Yes, this is also possible, but not very likely. We should see some version of it by 2019.