A welcome change to the Rules of Golf in 2019 is that if a player’s ball in motion accidentally hits the player or any person or outside influence

• There is no penalty to any player
• This is true even if the ball hits you the player, the opponent or any other player or any of their caddies or equipment
• The ball must be played as it lies
• Penalty still applies in stroke play if the player’s ball in motion hits another ball at rest on the putting green and both balls were on the putting green before the stroke, the player gets the general penalty (two strokes).  No penalty in match play and play the ball as it lies.  The ball that was at rest and moved is replaced.

Have a look at Rule 11 which covers the accidental movement of a ball, deliberate actions that affect a ball in motion plus what to do if a ball comes to rest ON a person, animal or moving outside influence (like a buggy).

The penalty for a double hit has also been removed.  If a player’s club accidentally hits the ball more than once, there has been only one stroke and no penalty.

Note this is only if the double hit is accidental!  The video doing the rounds of an intentional double hit to get a ball around a tree while hilarious is completely against the rules!  Rule 10.1