What Is an 'Outside Agency' in Golf?

And what happens when an outside agency interferes with your golf ball?

Dog steals Paul Casey's golf ball during the 2012 Alfred Dunhill Links Championship
Hey, where's that outside agency going with that golf ball?. Ross Kinnaird/Getty Images

"Outside agency" is a term used in the Rules of Golf for things that cause your golf ball ball at rest to move; or cause your moving golf ball to deflect or stop moving; and that are not you, your partner, your opponent (in match play), your caddies, the equipment of any of the above, or wind or water.

We'll give more examples below of things that are and are not outside agencies, but first, here's the rule book definition:

Definition of 'Outside Agency' in the Rules of Golf

The official definition of "outside agency," as written by the USGA and R&A and as it appears in the Rules of Golf, is this:

"In match play, an 'outside agency' is any agency other than either the player's or opponent's side, any caddie of either side, any ball played by either side at the hole being played or any equipment of either side.

"In stroke play, an outside agency is any agency other than the competitor's side, any caddie of the side, any ball played by the side at the hole being played or any equipment of the side.

"An outside agency includes a referee, a marker, an observer and a forecaddie. Neither wind nor water is an outside agency."

What Happens When a Outside Agency Moves Your Ball?

The definition of outside agency is most pertinent in the rule book in two particular rules:

Rule 18-1, ball at rest moved by an outside agency. Simple enough: The rule says this, "If a ball at rest is moved by an outside agency, there is no penalty and the ball must be replaced."

Rule 19-1, ball in motion deflected or stopped by outside agency. This section is longer, but the key part is this: When your ball is deflected or stopped by an outside agency, there is no penalty to you and you play your ball where it comes to rest. However, there are two exceptions dealing with golf balls that come to rest in or on living animals, and such strokes played on the putting green, that involve dropping or canceling the stroke.

So see the full Rule 19-1 for the details.

You can also watch a short explainer of outside agencies on YouTube to get a better sense of them.

More Examples to Explain Outside Agencies

The official definition above gives several examples of things that are outside agencies: a referee, a marker, an observer, a forecaddie.

Some more examples of things that are outside agencies:

  • A dog that scoops up your ball, a bird that flies away with it (both these things have happened more than once in pro tournaments), a squirrel that deflects it;
  • spectators;
  • members of the golf course's greenkeeping staff;
  • a stray golf ball played by a golfer on some other hole that comes bounding onto the hole you are playing;
  • objects being blown by the wind and that then hit your golf ball.

The wind itself is not an outside agency, but the Decisions on the Rules of Golf for Rules 18 and 19 include some odd scenarios relating to the wind. For example, a tumbleweed blowing across the course is an outside agency. Or how about this one: Your ball comes to rest inside a plastic bag; the wind then blows the plastic bag, moving your ball. Ruling? Outside agency, because in this scenario the wind is not moving your ball, it's moving the bag, which is then moving your ball.

Equipment of yourself or your side in stroke play, or, in match play, yourself and either side in the match, is not an outside agency. That includes things such as the golf cart (whether motorized or a pull cart) and player's towels.