Golf Provisional Ball

You can play a provisional ball if you think your original ball is lost and you don't want to delay play to look for it. But be sure to follow the correct procedure. If you think that your ball may be lost you should play a provisional ball. The only exception is in a water hazard or out of bounds.

You should tell your opponent in matchplay, or your marker or fellow competitor in stroke play that you intend to play a provisional ball. Play it before you or your partner looks for the lost ball.

If you don't do this, your second ball automatically becomes the ball in play and the original ball is assumed to be lost. So if you were playing a second ball from the tee, you will have played your third shot because you take a 1 stroke penalty for a lost ball.

You can continue to play strokes with your provisional ball until you reach the place where the original ball is likely to be. If you play a stroke from that place or any point nearer the hole, the provisional ball becomes the ball in play.

Unplayable lies
If you play a provisional ball from the tee then you find your original ball in bounds but in an unplayable position, you have three options. You can find somewhere within two club lengths to take a drop, or choose a spot on the ball-to-target line - but not nearer the hole. You may also play your next shot from where the last one was played -adding a 2 shot penalty.

In this situation you're not allowed to play a provisional because the ball becomes dead as soon as you found your original ball. You must go back to the tee and play a third ball, under penalty of stroke and distance.