Overview
The video assistant referee (VAR) is a match official in association football who assists the referee by reviewing decisions using video footage and providing advice to the referee based on those reviews.
The assistant video assistant referee (AVAR) is match official appointed to assist the VAR in the video operation room. The responsibilities of the AVAR include watching the live action on the field while the VAR is undertaking a "check" or a "review", to keep a record of reviewable incidents, and to communicate the outcome of a review to broadcasters.
Following extensive trialling in a number of major competitions, VAR was formally written into the Laws of the Game by the International Football Association Board (IFAB) on March 3, 2018. Operating under the philosophy of "minimal interference, maximum benefit", the VAR system seeks to provide a way for "clear and obvious errors" and "serious missed incidents" to be corrected.
Procedure
There are four categories of decisions that can be reviewed.
Goal/no goal – attacking team commits an offence, ball out of play, ball entering goal, offside, handball, offences and encroachment during penalty kicks.
Penalty/no penalty – attacking team commits an offence, ball out of play, location of offence, incorrect awarding, offence not penalised.
Direct red card – denial of obvious goal-scoring opportunity, serious foul play, violent conduct/biting/spitting, using offensive/insulting/abusive language or gestures.
Mistaken identity in awarding a red or yellow card.
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