Rule 18 is a rule that most golfers will regularly experience, as it covers situations where a ball in play is moved, whether purposely, accidentally or by the elements.
In every case where a ball at rest is moved by a competitor, or outside agent, it must be replaced where it was at rest. However, if it was moved by the wind, or other element, it must be played from where it comes to rest. This is where this statement under the rule comes into play;
*If a player who is required to replace a ball fails to do so, or if he makes a stroke at a ball substituted under Rule 18 when such substitution is not permitted, he incurs the general penalty for breach of Rule 18, but there is no additional penalty under this rule.
The penalty for a player causing their ball at rest to move, other than as a result of their stroke, is one stroke in both stroke-play and match-play.
However, if the player’s ball is not subsequently replaced at the right spot and the player makes a stroke at it from this wrong place, the penalty increases to the general penalty, which is two strokes in stroke-play or loss of hole in match- play.
Another example of how this penalty statement applies under Rule 18 is when a player, frustrated with a poor shot, picks up their ball and throws it into a nearby lake, from where it cannot be retrieved.
The player then places another ball on the spot from which the original ball was lifted and holes out.
The one who incorrectly substituted a ball under Rule 15- 2, incurs a penalty of two strokes in stroke-play, but the effect of the penalty statement is that they do not incur an additional penalty stroke for lifting their ball without authority.
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