My question is if 12 players are on the field of play and a goal is scored, what must the ref do either if the game has started for one minute after the kick off and the 12th player is noticed or the game has not restarted from a kick off after the goal is scored.USSF answer (December 12, 2006):
In all cases the extra player is removed and cautioned (unless an outside agent) for unsporting behavior.
If the extra player is discovered only after the ball has been kicked off, the goal counts. The game is restarted in accordance with the Law–i. e., if it went out of play, the restart is a throw-in, corner kick, goal kick, or free kick, depending on the reason the ball was out of play. If the referee stopped play, it is an indirect free kick from the place where the ball was when the referee stopped play.
If the extra player is discovered BEFORE the kick-off, the goal is canceled only if the extra player was on the scoring team or if the extra person was an outside agent who, in the opinion of the referee, did not in any way interfere with play or any player. The restart is determined by who the extra “player” was. If it was an outside agent–not a player or a substitute or substituted player–the restart is a dropped ball at the top of the defending team’s goal area. If it was a player who had left the game with the referee’s permission but re-entered without permission , the restart is an indirect free kick for the defending team, to be taken from within their goal area. If it was a substitute who had entered without the referee’s permission, the restart is an indirect free kick to be taken from the defending team’s goal area.