How VAR works in football

The video assistant referee (VAR) was formally written into the Laws of the Game by the International Football Association Board (IFAB) on 3 March 2018, operating under the philosophy of “minimal interference, maximum benefit” ^[1]. Despite its widespread presence in modern football, the system is deliberately restricted in scope. A video official cannot re-referee an entire match; instead, the protocol strictly dictates what can and cannot be reviewed ^[1].

The four reviewable categories

According to the Laws of the Game documented by IFAB, a VAR is permitted to assist the on-field referee in only four match-changing categories of decisions ^[1]:

• Goal/no goal: Assessing whether an attacking team committed an offence in the build-up, whether the ball went out of play, whether the ball crossed the goal line, offside positions, handballs, and offences or encroachment during penalty kicks ^[1].
• Penalty/no penalty: Checking whether an offence was incorrectly awarded or missed, whether the attacking team committed an earlier infringement, the physical location of an offence (inside or outside the penalty area), or whether the ball had gone out of play ^[1].
• Direct red cards: Reviewing incidents involving the denial of an obvious goal-scoring opportunity, serious foul play, violent conduct such as biting or spitting, or the use of offensive, insulting or abusive language or gestures ^[1]. Second yellow cards leading to dismissals cannot be reviewed ^[1].
• Mistaken identity: Ensuring that disciplinary action is applied to the correct player when a yellow or red card is issued ^[1].

Ordinary fouls outside the penalty box, corners, throw-ins, and standard yellow-card challenges fall outside the VAR’s jurisdiction unless they directly relate to one of the four core categories ^[1].

The review process and on-field monitors

The VAR and the assistant video assistant referees (AVARs) automatically check every decision made by the match referee that falls under the four reviewable categories ^[1]. Many checks pass unnoticed as “silent checks”, where video officials confirm that no error was made without halting the game ^[1].

When a potential mistake requires time to review, the referee delays play and signals the check by touching their ear ^[1]. Under the protocol, an on-field decision will not be changed unless the footage demonstrates a “clear and obvious error” ^[1].

How an incident is resolved depends on whether the decision is factual or subjective ^[1]:

• Factual matters: Decisions involving objective facts—such as whether a player was offside or whether contact occurred inside or outside the penalty box—can be overturned directly on the advice of the VAR without the referee consulting a screen ^[1].
• Subjective matters: Where a decision requires interpretation—such as the severity of a challenge or whether a handball occurred—the VAR recommends an on-field review (OFR) ^[1]. The referee indicates this by forming the outline of a television screen with their hands and moving to the pitchside monitor, located in the referee review area (RRA) ^[1].

During an on-field review, slow-motion replays are restricted to determining points of physical contact or handball placement, while full-speed replays must be shown to evaluate the intensity and force of an incident ^[1]. In all instances, the final decision remains solely with the on-field referee, who retains the authority to reject the VAR’s recommendation ^[1].

Offside and camera systems

The VAR setup uses extensive technology to review passages of play. Full tournament setups can incorporate up to 42 cameras, including ultra-slow-motion equipment, host broadcast feeds, and specialised offside technology ^[1]. In the video operation room (VOR)—which can be located inside a stadium or in a centralised hub such as Stockley Park in England or Atlanta in Major League Soccer—the VAR is supported by replay operators and up to three AVARs ^[1]. AVAR2, for example, is stationed specifically to assist with offside checks ^[1].

Conduct and disciplinary rules

The Laws of the Game strictly protect the integrity of the review area ^[1]. Players and team officials who aggressively make the television review signal can receive a yellow card ^[1]. Entering the pitchside referee review area results in an automatic caution, while any unauthorised person entering the video operation room faces an immediate red card ^[1].