The Unplayable Ball (Rule 28)
Issue: What if I am unable to make a shot on my ball?
Answer: One of the less known, but more useful, rules in golf is that of the unplayable ball. Rule 28 gives a golfer the option, at any time other than in a water hazard, to declare their ball unplayable. The player is the only one who can say it is unplayable. If the player invokes this rule, the person will receive a penalty stroke, but then they have the following options:
You can play a ball from the spot your original ball was last played, called "stroke and distance".
You can drop a ball within two club lengths of where the ball lies, no closer to the hole than it currently sits. If the ball is in a bunker, it must remain in the bunker.
You can draw a line between the flag and your ball and drop a new ball as far back as you would like along an extension of that line away from the hole. Once again, if the ball is in the bunker, it must remain in the bunker.
United States Golf Association (USGA) and the Royal & Ancient Golf Club (R&A)