The ruling in plain English
If it is known or virtually certain that you caused your ball at rest to move, replace it on its original spot, estimating that spot if necessary. You normally add one penalty stroke, but no penalty applies when one of Rule 9.4b's exceptions covers the accident.
Check these facts first
A ball is treated as moved only when that is known or virtually certain. When the player causes a ball at rest to move, it must normally be replaced on its original spot. The player normally gets one penalty stroke, but Rule 9.4b lists exceptions including accidental movement during search, on the putting green, and during certain reasonable Rules procedures.
Your on-course procedure
- 1
Confirm that the ball actually moved and that it is known or virtually certain you caused it.
- 2
Identify whether an exception applies, such as accidental movement while searching, on the putting green, or while reasonably applying a Rule.
- 3
Replace the ball on its original spot; estimate the spot if it is not known.
- 4
If no exception applies, add one penalty stroke.
Count it correctly
Normally one penalty stroke; no penalty when a listed exception applies.
The exact outcome depends on the stated facts and format of play. Apply any exception below before recording the penalty.
Know when the answer changes
- No penalty applies in the exceptions listed in Rule 9.4b, including accidental movement during a fair search, on the putting green, or during specified reasonable Rules actions.
- If the ball starts moving during the backswing or stroke and the stroke is made, Rule 9.1b applies instead.
Avoid these wrong turns
- Playing the ball from its new position instead of replacing it.
- Assuming every accidental movement is penalty-free.
Check the official wording
This independent guide is a plain-English aid. The current Rules, Interpretations and any course Local Rules control the ruling.
Would you make the right call?
Answer one situation from this guide, then try the full rules challenge for bragging rights.