(Reuters) - Factbox on the Video Assistant Referee (VAR) system which will be used at the World Cup finals for the first time in Russia:
The VAR is a match official who monitors video footage of the game for incidents that the on-pitch referee and his assistant referees might have missed.
A VAR, one of 13 FIFA qualified referees, and three assistants will monitor each of the 64 matches at the World Cup from an operations room in Moscow.
They will have access to the pictures from 33 broadcast cameras as well as two cameras dedicated to aiding offside decisions. Eight of the cameras will provide “super slow-motion” and four “ultra slow-motion” pictures.
Another dedicated camera will be installed behind each goal for the matches in the knockout stages of the tournament.
The VAR will become involved only in the following instances:
* Goals and offences leading up to a goal
* Penalty decisions and offences leading up to a penalty
* Direct red cards
* Cases of mistaken identity
Yes, for some incidents, the referee will act on information from the VAR, in others they will view the footage at the side of the pitch.
The on-field review will take place in the following circumstances:
* When a goal has been scored, in the case of a foul committed by an attacking player or for offside interference.
* On penalty decisions, for a foul leading up to penalty or a foul by an attacking player.
* All direct red card incidents.
The referee will act on VAR advice in the following circumstances:
* When a goal has been scored, to decide if a player was in an offside position leading up to the goal or if the ball had gone out of play leading up to the goal.
* On penalty decisions, to decide whether a foul was committed inside or outside the penalty area, if the ball had gone out of play leading up to penalty or if a player was in an offside position leading up to penalty.
* All cases of mistaken identity.
Compiled by Nick Mulvenney, editing by Toby Davis