Rule 18. Ball at Rest Moved
Definitions
All defined terms are in italics and are listed alphabetically in
the Definitions section — see pages 5-18.
18-1. By Outside Agency
If a ball at rest is moved by an outside agency, there is no penalty
and the ball must be replaced.
Note: It is a question of fact whether a ball has been moved by an
outside agency. In order to apply this Rule, it must be known or
virtually certain that an outside agency has moved the ball. In the
absence of such knowledge or certainty, the player must play the
ball as it lies or, if the ball is not found, proceed under Rule 27-1.
(Player’s ball at rest moved by another ball — see Rule 18-5.)
18-2. By Player, Partner, Caddie or Equipment
g a. General
When a player’s ball is in play, if:
(i) the player, his partner or either of their caddies lifts or
moves it, touches it purposely (except with a club in the
act of addressing it) or causes it to move except as permitted
by a Rule, or
(ii) equipment of the player or his partner causes the ball to move,
the player incurs a penalty of one stroke. If the ball is moved, it
must be replaced, unless the movement of the ball occurs after
the player has begun the stroke or the backward movement of
the club for the stroke and the stroke is made.
Under the Rules there is no penalty if a player accidentally
causes his ball to move in the following circumstances:
• In searching for a ball in a hazard covered by loose impediments
or sand, for a ball in an obstruction or abnormal
ground condition or for a ball believed to be in water in a
water hazard — Rule 12-1
Rule 18 57
• In repairing a hole plug or ball mark — Rule 16-1c
• In measuring — Rule 18-6
• In lifting a ball under a Rule — Rule 20-1
• In placing or replacing a ball under a Rule — Rule 20-3a
• In removing a loose impediment on the putting green — Rule
23-1
• In removing movable obstructions — Rule 24-1.
g b. Ball Moving After Address
If a player’s ball in play moves after he has addressed it (other
than as a result of a stroke), the player is deemed to have moved
the ball and incurs a penalty of one stroke. The ball must be
replaced, unless the movement of the ball occurs after the
player has begun the stroke or the backward movement of the
club for the stroke and the stroke is made.
18-3. By Opponent, Caddie or Equipment in Match Play
g a. During Search
If, during search for a player’s ball, an opponent, his caddie
or his equipment moves the ball, touches it or causes it to move,
there is no penalty. If the ball is moved, it must be replaced.
g b. Other Than During Search
If, other than during search for a player’s ball, an opponent,
his caddie or his equipment moves the ball, touches it purposely
or causes it to move, except as otherwise provided in the Rules,
the opponent incurs a penalty of one stroke. If the ball is
moved, it must be replaced.
(Playing a wrong ball — see Rule 15-3.)
(Ball moved in measuring — see Rule 18-6.)
18-4. By Fellow-Competitor, Caddie or Equipment in
Stroke Play
If a fellow-competitor, his caddie or his equipment moves the player’s
ball, touches it or causes it to move, there is no penalty. If
the ball is moved, it must be replaced.
(Playing a wrong ball — see Rule 15-3.)
58 Rule 19
18-5. By Another Ball
If a ball in play and at rest is moved by another ball in motion
after a stroke, the moved ball must be replaced.
18-6. Ball Moved in Measuring
If a ball or ball-marker is moved in measuring while proceeding
under or in determining the application of a Rule, the ball or
ball-marker must be replaced. There is no penalty, provided
the movement of the ball or ball-marker is directly attributable
to the specific act of measuring. Otherwise, the provisions of
Rule 18-2a, 18-3b or 18-4 apply.
*Penalty for Breach of Rule :
Match play — Loss of hole; Stroke play — Two strokes.
*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.
Note 1: If a ball to be replaced under this Rule is not immediately
recoverable, another ball may be substituted.
Note 2: If the original lie of a ball to be placed or replaced has
been altered, see Rule 20-3b.
Note 3: If it is impossible to determine the spot on which a ball
is to be placed, see Rule 20-3c.
