Lost Ball, Out of Bounds and the Provisional Ball: Golf Rule 18 Explained
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How we wrote this: A plain-English summary of Rule 18 of the official Rules of Golf and Model Local Rule E-5 as published by the R&A, checked October 29, 2026. Your club's posted Local Rules decide whether E-5 is in effect.
Few things slow a round like a lost ball. Here's what Rule 18 says, and how a provisional ball saves the walk back.
Stroke and distance
Under Rule 18, you can always take stroke-and-distance relief: add one penalty stroke and play again from where you made the previous stroke. When your ball is lost or out of bounds, Rule 18.2 says stroke-and-distance relief must be taken, unless a Local Rule like E-5 offers another option.
When a ball is lost
Rule 18.2a: a ball is lost if not found within three minutes after you or your caddie begin searching. If a ball is found in that time but you're not sure it's yours, you must promptly try to identify it.
When a ball is out of bounds
A ball is out of bounds only when all of it is outside the boundary edge of the course. If any part of the ball touches the ground or anything else inside the boundary, or is above the boundary edge or any other part of the course, it's in bounds. You may stand out of bounds to play a ball that's on the course.
The provisional ball (Rule 18.3)
If your ball might be lost outside a penalty area or out of bounds, you can play a provisional ball to save time.
- Announce it. It isn't enough to say you're "playing another ball." Rule 18.3 says you must use the word "provisional" or otherwise clearly indicate it. Without an announcement, the second ball is in play under stroke and distance.
- Keep playing it while it's farther from the hole than where your original ball is estimated to be. It stays a provisional.
- It becomes your ball in play (under stroke and distance) if the original is lost anywhere except in a penalty area or is out of bounds, or once you play the provisional from a spot nearer the hole than where the original is estimated to be.
- You must abandon it if you find the original on the course outside a penalty area within the three minutes (play the original as it lies), or if the original is in, or known or virtually certain to be in, a penalty area.
Model Local Rule E-5: the two-stroke alternative
Many clubs adopt MLR E-5 for general play. When a ball hasn't been found or is known or virtually certain to be out of bounds, it lets you drop in a large relief area between where the ball is estimated to have come to rest or crossed the boundary and the edge of the fairway, not nearer the hole, for two penalty strokes. The R&A says that makes it comparable to stroke and distance.
Limits, per the Committee Procedures:
- It's meant for casual rounds and club competitions, and is not appropriate for professional or elite amateur competitions.
- It can't be used for an unplayable ball or for a ball known or virtually certain to be in a penalty area.
- For handicap scoring, follow your handicapping authority's guidance; see our World Handicap System guide.
Also see our guide to the 2026 Model Local Rules.