What is the penalty for a lost ball or a ball out of bounds?

Under Rule 18.2 of the 2023 Rules of Golf, you take stroke-and-distance relief: add one penalty stroke and play the original or another ball from where your previous stroke was made.

• Lost: a ball is lost if it is not found within three minutes after you or your caddie begin to search. If a ball is found in that time but you are unsure it is yours, you have a reasonable time to identify it, even after the three minutes.
• Out of bounds: a ball at rest is out of bounds only when all of it is outside the boundary edge of the course. It is in bounds if any part of it touches the ground or anything else inside the boundary edge, or is above the boundary edge. You may stand out of bounds to play a ball on the course.

Exception: if it is known or virtually certain what happened to the ball (for example it is in a penalty area, in an abnormal course condition, or was moved by an outside influence), you may use the relief that applies to that situation instead.