Soccer Offside Rules

He will undoubtedly have an easy time grasping the basic rules, but at the point of the game when the refs will stop an attacker for offside for the first time, he'll start having problems. He'll ask you about the soccer offside rules and you'll probably have to explain him over and over again for a few times before he'll be able to judge an offside by himself.

I must admit, when my friend asked me "why was that guy called offside?" it took me over 20 minutes and 5-6 in-match offside situations to explain things to him but in the end he finally grasped the idea.

Here's what I told him and here are the answers you should give to your friends when they'll ask you about the soccer offside rule: 

When is a player called offside?
A player, usually a striker, is called offside when he is nearer to the other team's goal than both the ball and the second last opponent. The second last opponent usually being the last defender from the opponent team, an offside occurs when the striker is closer to the opposing team's goal than that team's last defender.

To put it simply, try to picture an imaginary line on Team A's last defender, a line parallel to the goal line. If Team B's striker is over this line when his teammate passes the ball, then he is offside. If Team B's striker is on the same line as Team A's last defender (or under the line) then he is in a correct position.

One more thing to look after in an offside: it doesn't matter if Team B's striker is over this line when he receives the ball. The moment to look after is the moment the midfielder passes the ball, which will trigger an offside if the striker is over the last defender line.

Offside Rules

The striker was on the same line as the defender, why hasn't he been called offside?
It's not an offside if they are both "on the same line", however there's a slight twist to this soccer offside rule. Even if the players are on the line with their feet, but the striker is leaned forward, a keen referee will call an offside. It's an offside by the slightest of margins, but still an offside. Subsequently, if the defender is leaned forward, he leaves the striker in offside.

What's a "passive offside"?
The passive offside is one of the most debated FIFA soccer rules over the last few years and it seems they finally found a good way to handle it. A player is in "passive offside" if he's in an offside position but doesn't play the ball, in which case the ref doesn't call the offside.

A tricky striker can confuse the defense into laying low thinking an offside will be called, only to avoid playing the ball, allowing another teammate to pick up the ball, and potentially score.

Obviously, what "playing the ball" means is slightly interpretational. Even if the striker in the offside position doesn't touch the ball, but influences the play otherwise (runs towards the ball, covers the goalkeeper's viewpoint and so forth) he comes out of passive offside and the referee blows the call.