How much strokes does an out of bounds in golf cost you?

Answer 1

The penalty for hitting out of bounds is one shot, and you need to play another shot from where you played the original, so effectively it is two.

If you hit you tee shot, 1st shot, out of bounds, add one stroke penalty, 2nd shot, them you are playing 3 off the tee, and therefore 4 from the fairway or rough.

Answer 2

There is a one stroke penalty and you must replay the shot from the same position, or as close as possible to original position.

Simply, you stand on the tee, you hit your tee shot out of bounds (1), you take your penalty stoke (2) and replay the shot from the tee (3) so when you get down the fairway your next shot is your 4th.