Abnormal Course Conditions: What They Are ... And Aren't

An "abnormal course condition" is any of several poor physical conditions on a golf course that, when one exists and your golf ball or stance is affected by it, entitle the player to (usually free) relief.

Before we get into specifics, a note that what today the rule book calls "abnormal course conditions" were, in the past, known as "abormal ground conditions." The USGA and R&A switched from "abnormal ground conditions" to the new term when a new rule book was issued for 2019.

Definition in the Rules of 'Abnormal Course Conditions'

This is the official definition of "abnormal course conditions" as it appears in the Rules of Golf, which is jointly written by the USGA and R&A:

"An animal hole, ground under repair, an immovable obstruction, or temporary water."

That's simple enough ... so long as you understand what of those components themselves are.

Examples of Abnormal Course Conditions

Let's break down that rule book definition. Abnormal course conditions are:

• Temporary water: What used to be called "casual water" is any temporary accumulation of water on the golf course, for example, puddles of water left after a rain. You must be able to see water either before or after you take your stance to get relief from temporary water. Snow or natural ice can be considered casual water.
• Ground under repair: Exactly what it sounds like. If the course superintendent or maintenance staff are working on a part of the course turf, that area is called "ground under repair" and should be designated as such (white lines on the ground, or staking or roping off the area). Any hole dug by greenskeeping staff or piles of material left for removal are GUR even if not marked as such.
• Animal holes: Holes made by burrowing animals, reptiles and birds are abnormal ground conditions, as is the dirt thrown out of the holes in their digging. 
• Immovable obstruction: Any obstruction that can't be moved (or at least without undue effort); the cart path and sprinkler heads are examples.

And Some Things That Are Not Abnormal Course Conditions

• Grass clippings left in place after mowing (i.e., not piled for removal).
• Wet ground, spongy ground, mushy ground that does not have any water showing above ground even after you take your stance.
• Dew or frost on the ground.
• Holes made by worms and insects also don't count as abnormal course conditions (worms and insects themselves are classified as loose impediments).
• Aeration holes on putting greens are not covered by the phrase "holes made by greenkeepers" as mentioned in the definition of ground under repair, and, therefore, are not ACC.

The governing bodies go over many other scenarios (some you've probably never even thought of) in their Interpretations on Rule 16-1 (Abnormal Course Conditions.

What to Do When Your Ball Is in an Abnormal Course Condition

Abnormal course conditions — and what to do if your golf ball comes to rest in or on one — are covered in the rule book in Rule 16-1.

Note first that you can play out of the abnormal course condition if you choose.

And note that it's not just your ball touching an ACC that gets you relief; if an ACC interferes with your stance or the area of your swing — or, on the putting green only, with your line of putt — you also get relief.

Outside of bunkers and the putting green, a ball in an abnormal course condition can be lifted and dropped within one club-length of the nearest point of relief. There is no penalty.

Free relief applies in bunkers only if the ball is dropped inside the bunker; the golfer can drop outside the bunker with a 1-stroke penalty.

And on the putting green, the ball is placed rather than dropped in taking relief from an abnormal course condition. Always keep in mind the nearest point of relief cannot be closer to the hole.

Also, if your ball is inside the boundary of a penalty area, or out of bounds, no free relief from an abnormal course condition applies.

See Rule 16-1 for more details, exceptions and what to do if your ball goes into an abnormal ground condition and you can't find it.

The USGA has a good video going over abnormal course conditions. Watch it here.