Offside is a football rule that stipulates that a player of the attacking team, at the moment the ball is passed to him by his teammate, must be in the line or behind the opposing players, including the opposing goalkeeper.

To understand what offside is, we should learn a little history.

In the very beginnings of football, this rule did not exist. The attackers often got one-on-one opportunities with the goalkeeper. For this reason, the offside rule was introduced in 1863, which reads: A player is in an illegal position only when there are no three opposing players in front of him, including the goalkeeper.

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After that, in 1925, the rules were corrected. Namely, a player must have at least two opposing players in front of him, including the goalkeeper. It means, at least one defender must be in front of the attacker. In 1990, new changes were introduced. This time, it was not considered an illegal position if the player is in line with the defender.

Well with this Offside rule, I think Rashford interfered. pic.twitter.com/w3wa2mvzkV

— Kelechi (@kelxchi) January 14, 2023

It should be noted that the linesman is not obliged to signal an offside position if the ball is not directed to the player in question.

A player who is offside should only be penalized if the ball is sent towards him by one of his teammates at that moment, either intentionally or accidentally. Then he actively participates in the game, being in an illegal position.

A player is considered to be in an illegal position when the ball is directed to him. If the ball was sent to him while he was not in such a position, there is no offside. If a player in an offside position moves back in front of the last defensive players, regardless of the fact that he is trying to move from offside and go backwards, it is still looked at where he was at the time the ball was sent.

Before the introduction of VAR technology, there were many refereeing errors that directly affected the outcome of the match. Sometimes goals were recognized even though it was an illegal position, and sometimes they were canceled even though the player was not behind the defenders.

FIFA announced at the World Cup in Qatar that it is starting to apply a semi-automatic interpretation of offsides.

“The system will help VAR-referees, as well as those on the field, to make faster, more accurate and more reliable decisions,” they said from FIFA headquarters in Zurich.

In order for the spectators in the stadium and in front of the television screens to have fun while the referees, with the help of new technology, decide whether it was offside or not, and wait for the game to continue, the dubious action will be shown on the scoreboards and screens as a 3D animation.

So, offside is a law in football that states that if a player is offside when the ball is touched or played by a teammate, he can’t actively participate in the play.

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A player is offside if he is closer to the opposition’s goal line than both the ball and the last defender (who is usually the last outfield player), but only if the player in the opposition’s half. When the ball is put back in play after it has left the field, it can never be offside. Thus, one can never be offside after directly receiving the ball from a throw-in, goal kick, corner.

In enforcing this rule, the referee is largely dependent on the assistant referee, who usually holds the line with the receiver in second place – the last defender, the ball or the halfway line, whichever is closer to the goal line of his relevant end.

The assistant referee signals that an offside offense has occurred by first raising his flag upright without moving and then, when the referee has acknowledged it, by raising his flag in a manner indicating the location of the offence.