The USGA, in conjunction with The R&A in St. Andrews, Scotland, writes, interprets and maintains the Rules of Golf to guard the tradition and integrity of the game.The two organizations are joint authors and owners of The Rules of Golf and Decisions on the Rules of Golf.Through an agreement with The R&A, the Rules jurisdiction of the USGA includes only the United States, its possessions and Mexico.The latest version went into effect Jan. 1, 2012, with the next revision taking effect Jan. 1, 2016.
STRIKING THE BALL: To understand this rule, the definition of a STROKE must be understood. There are several key points in the definition that must be present for a stroke to have been made:
(i) The club must be moving forward.
(ii) The player must have intent to fairly strike and move the ball. This is why a practice swing is not a stroke, it doesn't have intent.
(iii) The head of the club must be used, and the ball must not be spooned, scraped, or pushed.
(iv) A player also may not use artificial devices or accept physical assistance from Mother Nature.
PENALTY FOR STRIKING THE BALL IMPPOPERLY: TWO- STROKES IN STROKE PLAY AND LOSS OF HOLE IN MATCH PLAY. DISQUALIFICATION PENALTY FOR USING ARTIFICIAL DEVICES.
A common situation is when a player strikes his ball more than once in the course of a stroke. If this occurs, the player must add one penalty stroke, making two strokes total. The ball is played where it lies. An example would be hitting a ball out of a bunker or high grass. I'm sure we all have hit the ball straight up where the club hit the ball once again on follow through.
A player is not allowed to play a moving ball.
PENALTY: TWO STROKES IN STROKE PLAY AND LOSS OF HOLE IN MATCH PLAY. The exceptions without penalty would be a ball falling off the tee in the process of a stroke, striking a ball more than once in the process of a stroke (mentioned above), playing a moving ball in a water hazard.
NOTE-- There is also no penalty under this rule if a ball moves after the player begins his swing, however, the player would be penalized if he is responsible for the movement of the ball other than the situations listed above. In other words if your ball is in high grass, and after you begin your backswing your ball moves. If your swing is continued, you are not penalized for playing a moving ball but you are penalized one stroke for moving your ball after address.
NOTE-- Strokes taken while playing a wrong ball do not count towards the players score.