A golfer typically takes a drop after hitting his ball in an area from which he either can’t play another shot or chooses not to play his next shot. As a general rule, if the ball is in a hazard or is out of bounds, the player is assessed a penalty stroke for taking the drop. If the ball arrives in unplayable ground through no fault of the golfer he's frequently granted relief and is not assessed a penalty.
If a player takes a drop rather than hitting from a hazard -- such as a water hazard, for example -- she must take a 1-stroke penalty. According to Rule 26-1b of the Rules of Golf, she may drop the ball as far from the water hazard as she wishes, provided the spot is farther from the hole than the point at which the ball entered the hazard. Also, the location where the ball entered the water hazard must remain directly between the hole and the drop location.
Players may be granted relief when hitting into a normally playable area that’s been temporarily altered, such as ground under repair or a mound made by a burrowing animal. For example, when the course is wet a ball hit into the fairway may become embedded in the ground. Pursuant to Rule 25-2, the golfer may lift and clean the ball, then may drop it without penalty in a playable location. The ball must be dropped as near to the original location as possible, but not nearer to the hole.
How to Drop
Rule 20-2a explains how the drop is executed. The drop must be made by the player who hit the shot. The golfer must stand up straight and extend his arm at shoulder level, then drop the ball. If the ball strikes any person, or any person’s equipment, the ball must be re-dropped without penalty. According to Rule 20-2c, the ball must also be re-dropped without penalty under a variety of circumstances, such as if it rolls from normal ground into a hazard, rolls from a hazard onto normal ground, rolls onto the green and remains there, or rolls out of bounds and remains there.
The No-Spin Zone
Under the Rules of Golf the word “drop” is taken literally. The player may not spin the ball to try to influence its final location. Doing so incurs a 1-stroke penalty, according to U.S. Golf Association Decision 20-2a/1. Additionally, USGA Decision 20-2a/8 prevents a player from testing the drop zone by dropping a ball other than her own to see how it will roll.