Video Assistant Referees

The Video Assistant Referee system (VAR) was introduced into UEFA competitions in 2019 following extensive testing and training of referees.

Background and timeline
On 3 March 2018, the International Football Association Board (IFAB) decided to allow the use of VAR in football following a two-year period of "live experiments with video assistance for clear errors in match-changing situations". IFAB also made various amendments to the laws of the game 2018/19 required to ensure they reflect the use of VAR where applied, including the introduction of the VAR protocol of the laws.

At their meeting on 27 September 2019, the UEFA Executive Committee decided that VAR would be introduced to UEFA competitions from the start of the 2019/20 season. Following an autumn of testing and training, that start date was then brought forward to the UEFA Champions League round of 16 (February–March 2019) at the December meeting of the Executive Committee.

Training
Following the September announcement, courses with the referees took place in Zeist (Royal Netherlands Football Association HQ), Madrid, Istanbul, Lisbon and Malaga. The courses catered for referees with VAR experience as well as male and female officials new to VAR. Meanwhile, background testing of the operational and technological aspects took place at national team and club matches.

Operational set-up
In principle, there is a video assistant referee, an assistant video assistant referee and two video operators on site at all UEFA games where VAR is being utilised. When the VAR team is in place, there is no AAR (additional assistant referee).

How it works
The VAR team at the stadium will constantly check for clear and obvious errors related to the following four match-changing situations:

1) goals
2) incidents in the penalty area
3) red cards
4) mistaken identity

• The VAR team will check all match-changing situations, but will only intervene for clear and obvious mistakes. The referee can hold up play while a decision is being reviewed. 
• If the VAR review provides clear evidence for a serious mistake in one of the game-changing situations, the VAR can then ask the referee to conduct an on-field review. The final decision can only be taken by the referee. 
• The VAR is also able to take into account any infringement that could have taken place in the immediate build-up to the incident (the attacking phase of play).
• For 'factual' decisions (e.g. offsides, fouls in or outside the penalty area), the VAR can simply inform the referee of those facts and the on-field view screen isn't needed, but it is always the referee who takes the final decision.
• The on-field review process will be communicated within the stadium using either the stadium screens or the public announcement system.

Key documentation
IFAB protocol 
Programme insert for UEFA Champions League clubs