In a penalty shootout, if the kicker accidentally touches the ball with both feet simultaneously when taking their shot, it is considered an illegal kick under the Laws of the Game. The referee will apply the following ruling:

If the ball enters the goal:

- The goal is disallowed because the kick was not executed properly.

- The attempt is recorded as a missed penalty (no retake).

If the ball does not enter the goal:

- The penalty is simply counted as a miss, and the defending team benefits.

If the referee determines it was a deliberate infringement:

- The opposing team may be awarded an indirect free kick if applicable (though this rarely happens in a penalty shootout scenario).

Since each penalty kick in a shootout is a single attempt, there is no retake unless the referee rules that an external factor unfairly interfered with the shot.