I mentioned this at the breakfast event today and thought I'd post it here for those that didn't hear and don't visit the gc.com forums.
4.14. Challenge Caches
What is a Challenge cache?
A challenge cache requires that geocachers meet a geocaching-related qualification or series of tasks before the challenge cache can be logged. Waymarking, Benchmarking, Challenges and Wherigo-related tasks also qualify. The additional qualification or geocaching-related tasks are considered the basis of a challenge cache, rather than Additional Logging Requirements (ALRs).
Challenge caches vary in scope and format. All challenge caches must be in the affirmative and require that something be accomplished. Challenge cache owners must demonstrate that there are sufficient available caches to meet the challenge at the time of publication. Reviewers may ask the cache owner to demonstrate that they have previously met the challenge and/or that a substantial number of other geocachers would be able to do so.
How will you know when the challenge cache requirements have been met?
Importantly, cache owners must consider how they will substantiate claims that the cache requirements have been met. The challenge criteria on the cache page must reflect this consideration, and must be verifiable through information on the Geocaching.com website. Challenge caches relying solely on third-party software for verification will not be published. Cache owners will need to ensure that geocachers can verify that they have completed the cache requirements without compromising their privacy. Challenge cache owners may also be asked to outline a long-term cache maintenance plan.
What makes an acceptable challenge cache?
A challenge cache needs to appeal to, and be attainable by, a reasonable number of geocachers. A challenge cache may not specifically exclude any segment of geocachers. If a geocacher is required to alter their caching style or habits, such as avoiding a particular cache type to attain a specific percentage or average, the cache will not be published.
The requirements for meeting the challenge should be succinct and easy to explain, follow, and document. A lengthy list of "rules" would be sufficient reason for a challenge cache to not be published.
Additional points to consider when creating a challenge cache:
Challenge caches must contain the word "challenge" in the cache name.
Challenge caches are listed as the Mystery/Unknown cache type.
A Challenge cache must avoid undue restrictions. Specifically:
Challenge caches based on a specific list of caches, such as caches placed by a specific person or group, will generally not be published.
Challenge caches cannot include restrictions based on 'date found'; caches found before the challenge cache publication date can count towards the achievement of the challenge.
Challenge caches need to be attainable at any time while the cache is active. A cache that requires "100 multi-caches found in 2011" would not be publishable, as would not be attainable by someone new to the game.
A Challenge cache based on non-accomplishments, such as DNFs, will not be published.
One should not have to 'give up' finding other caches to achieve a challenge cache's requirements. To state that "10% of your find count needs to be Attended Logs" would require the geocacher to stop finding other types of caches and could affect their overall enjoyment of the game.
Challenge caches may not require the publication of a new cache or waymark as a challenge criteria; challenge caches must be achievable by those who do not own caches or waymarks.
Challenge caches must not require geocachers to log caches that are disabled or archived.
A challenge cache should recognize the completion of a personal achievement, rather than the winner of a competition. For example, a challenge cache based on "First to Finds" is a competition between geocachers, and is therefore not publishable.
A challenge cache must be attainable without the need to email the owner. The cache page must include the true coordinates or the means to calculate them, if a puzzle.
If a challenge cache is submitted within an area where a similar challenge cache already exists, then it will need to have a unique list of qualifying criteria (geocaches, waymarks, etc.).
From the Geocaching.com Geocache Listing Requirements and Guidelines:
Please be advised that there is no precedent for placing geocaches.
At times a geocache may meet the requirements for publication on the site but the reviewers, as experienced geocachers, may see additional concerns not listed in these guidelines that you as a geocache placer may not have noticed. The reviewer may bring these additional concerns to your attention and offer suggestions so that the geocache can be published.