When is a player considered "offside"?

A player is considered "offside" when they are involved in active play while being past the second last opponent when the ball is played. This means that at the moment the ball is played to them, they must be in a position that is not advantageous, which typically involves being closer to the opponent's goal line than both the ball and the second to last defender, usually the last outfield player. The concept is meant to prevent "goal-hanging" or players positioning themselves in front of the goal waiting for a pass without any regard for the game's flow.

To clarify further, just being past the last opponent does not make a player offside; they must also be involved in the play to be penalized. Additionally, merely standing in front of the goalkeeper or not having possession of the ball does not automatically constitute an offside situation either, as being in front of the goalkeeper or not having possession does not assess the player's position relative to the opponents and the ball at the crucial moment of the play.