The goal of golf is to hit the ball into each hole with as few strokes as possible; the basic rules of golf state that players must count each time they strike the ball and can't alter the course of play. Players generally must strike the ball where it lands.
If a player's ball lands out of bounds, the player must drop the ball close to the out-of-bounds marker. Doing so requires the player to add one stroke to the hole's score. If the ball lands in a water trap, the player drops the ball in play approximately where the ball crossed the plane into the water. Again, this incurs a one-stroke penalty.
In general, the player whose ball is farthest from the hole must play next. Officials often waive this rule when a player's ball is on the green close to the hole, although requirements vary between leagues. The most complex rules in golf, however, may be those dealing with obstructions. Players can remove so-called obstructions and loose sediment, but officials can find it challenging to determine what is an obstruction and what objects players have to navigate. Players also need to learn how to deal with a ball already on the green. In general, players can mark the ball's position and replace it but can't affect the turf around the ball or on the path to the hole.