Offside Violation
A player is in an offside position when nearer to his opponents' goal line than the ball, and when nearer to the goal line than at least two defenders. When a player is in his own defensive half, or when a goal kick, corner kick or throw-in has not yet been touched by another teammate, that player is not offside.
A player cannot be penalized simply for being in the offside position. That player has only committed an offside violation if he is in the offside position at the moment the ball touches or is played by a teammate, and if he interferes with play or with an opponent, or gains an advantage by being in that position.