Rules of Offside in Football

Of course. The offside rule in football can seem complicated, but it's much easier to understand when you break it down into two main questions:

Is the player in an offside position?
If so, did they commit an offside offence by becoming involved in the play?

Let's look at each part.

1. The Offside Position

A player is in an "offside position" if they are in the opponent's half of the field and are closer to the opponent's goal line than both the ball and the second-to-last opponent.

This sounds like a mouthful, but it's simpler with a visual. A player is only in an offside position if all three of these conditions are met at the moment the ball is passed by a teammate:

In the opponent's half: You can't be offside in your own half.
Ahead of the ball: The player must be in front of the ball.
Fewer than two opponents between them and the goal: This usually means being ahead of the last defender (not including the goalkeeper).

In the demo below, you can drag the Attacker (in red), the Ball, and one of the Defenders (in blue) to see when a player is in an offside position. The dotted line represents the "offside line," which is set by the second-to-last defender.

2. The Offside Offence

Being in an offside position is not against the rules by itself. A player only commits an offside offence if they are in that position at the moment the ball is passed forward by a teammate and then become actively involved in the play.

A player is considered "actively involved" if they do one of three things:

Interfere with play: This is the most common one—actually touching the ball after it was passed by a teammate.
Interfere with an opponent: This means preventing a defender from playing the ball, for example, by blocking their vision or challenging them for the ball.
Gain an advantage: This applies to situations where the ball rebounds off the goalpost, crossbar, goalkeeper, or an opponent to the offside player.

In the scenarios below, press the "Pass the ball" button to see when an offence occurs. The player marked with an "X" is in an offside position when the pass is made.

3. Exceptions to the Rule

Finally, there are three specific situations where a player cannot be called for an offside offence, even if they are in an offside position. This happens when they receive the ball directly from:

A Goal Kick
A Throw-in
A Corner Kick

This rule encourages more direct attacking opportunities from these set-piece restarts.

So, to summarize, always check for two things: First, is the player in an offside position when the ball is played? And second, if they are, do they become actively involved? If the answer to both is yes (and it's not a goal kick, throw-in, or corner kick), then it's an offside offence.