Obstructions (Rules Definition and More Info)

The definition of "obstruction" that appears in The Rules of Golf (written and maintained by the USGA and R&A) is this:

Any artificial object except for integral objects and boundary objects.
Examples of obstructions:
*Artificially surfaced roads and paths, including their artificial borders.
*Buildings and rain shelters.
*Sprinkler heads, drains and irrigation or control boxes.
*Stakes, walls, railings and fences (but not when they are boundary objects that define or show the boundary edge of the course).
*Golf carts, mowers, cars and other vehicles.
*Waste containers, signposts and benches.
*Player equipment, flagsticks and rakes.

To summarize, an "obstruction" is anything artificial on the golf course, with exceptions for any objects that define out of bounds, any construction that the local committee defines as an integral part of the course, or any immovable artificial object that is out of bounds.

The rule book definition further notes that "an obstruction is either a movable obstruction or an immovable obstruction."

So there are movable obstructions and immovable obstructions, and we bet you can figure out the difference between them. How a player deals with an obstruction depends on whether the obstruction is movable or immovable.

In the condensed Player's Edition of the rule book, "movable obstruction" is defined as "an obstruction that can be moved with reasonable effort and without damaging the obstruction or the course." And "immovable obstruction" is defined as "any obstruction that cannot be moved without unreasonable effort or without damaging the obstruction or the course, and otherwise does not meet the definition of a movable obstruction."

The rules generally provide free relief from obstructions on the golf course. Relief from movable obstructions is covered in Rule 15; relief from immovable obstructions is covered in Rule 16.