Robert, a referee of older youth players, asks:
A penalty kick is completed when the ball stops moving. How about giving me some examples when a ball stops moving during a penalty kick situation.
The International Board, in its infinite wisdom when it rewrote the Laws of the Game to make them simpler and easier to understand, wasn’t entirely successful in several of its changes. This is one of them. Note that almost the exact same language was used in Laws 10 and 14 to say when the kick was complete:
Law 10: The kick is completed when the ball stops moving, goes out of play or the referee stops play for any infringement of the Laws
Law 14: The penalty kick is completed when the ball stops moving, goes out of play or the referee stops play for any infringement of the Laws.
More to the point of your question, both Laws include “ball stops moving” as one of the ways that a kick from the mark (KFTM) or a penalty kick (PK) may be considered ended. This works fairly well for a KFTM and it also works for a PK taken in extended time. As long as the ball continues to move while making contact with any one or combination of the goalkeeper, goalframe, or the ground, a valid goal can be scored. Yet, at the same time, in each case no one else is allowed to participate in the play. Thus, if a PK in extended time or a KFTM struck the crossbar, rebounded backward onto the ground in front of the goal, but had acquired a spin which resulted in the ball now rolling forward a few feet into the goal, that goal would count. The same would be true if the ball rebounded from the crossbar to the back of the goalkeeper and then rebounded from there into the goal.
A regular, ordinary PK, however, is a bit different because, except for the original kicker, the ball can be played by anyone once it is in play (kicked and moved forward). During that time, it is entirely possible that the ball could be motionless … and it doesn’t matter because, with one exception, no one particularly cares when, whether, or even if the PK is “over.”
The exception is if an outside agent interferes with play at the taking of a penalty kick. Ordinarily, if play is stopped because of outside agent interference, the restart is a dropped ball. We can just picture some spectator, who supports the Orange team which is just about ready to defend against a PK, thinking that, if he or she ran onto the field after the PK was taken and interfered, the referee would have to stop play and then restart with a dropped ball (effectively taking the PK away from the hated opponent)! So the Laws of the Game provide that, if the interference occurs while the ball is moving toward the goal and hasn’t made contact as yet with any part of the goalframe or the goalkeeper, the restart will be a retake of the PK. Until the ball stops moving forward (not just stops moving), the PK is not “over” at least for the purpose of retaking the PK rather than having a dropped ball in the case of outside agent interference. The implicit theory of this provision is that a team which has been awarded a PK should have a reasonable opportunity to score and any event which interferes with that during the period from the ball being kicked and the ball reaching the immediate area of the goal should result in the offended team getting to redo the PK after all the dust has settled.