Challenge checker

What is it?

A Challenge checker uses program code that checks if a user has fullfilled the requirements of a challenge cache. Per the guidelines of Geocaching.com a challenge cache published after April 21, 2015, must include a link to a web-based challenge checker. So far Project-GC is the only allowed challenge checker. More general information about challenge caches is available in the article challenge caches, for example information about challenge exceptions.

How does it work?

A challenge checker consists of two parts: a challenge checker script and a tag. The script is a piece of program code written in the programming language Lua. The script checks for a certain condition, for example a script can check if the user has found 100 mystery caches. Another script can check if a user found a cache on 365 calendar days. A tag associates one or more scripts with a specific challenge cache, and defines (customizes) cache type and quantity for a script to match the challenge cache.

The tag links a checker script, a challenge cache, and (optionally) a set of parameters for the checker script. This means that the same script can be used both for a challenge that requires the user to have found 100 mystery caches and a challenge that requires the user to have found 1000 traditional caches, since the cache type and quantity of finds required is specified in the tag.

The same checker script can be used for multiple challenge caches (For instance, most calendar challenges are handled by the same checker script). The tag is what makes this possible.

Project-GC also calculates how difficult a challenge is, more information at: Challenge difficulty

Checker Requests

Challenge checkers are created by volunteers and can be requested in the Checker request forums, it is important to read the READ FIRST-post before posting a request.

Disabled checkers

Project-GC has a system for disabling the challenge checker if the cache lacks the Challenge-attribute, this is because the challenge-attribute is mandatory per the guidelines.

FAQ

Visit Project-GC's FAQ to find answers to many of the most common questions.

Related paid membership feature

If a user have a paid membership Project-GC automatically runs challenge checkers for the user in the background. See the article about Auto-challenge-checkers for more information.

With a paid membership there is no limit on how many challenge checkers you can run. Non paying users are only allowed to run 10 challenge checkers per 24 hours. The limit is a rolling rate limit.

The Map of challenge caches is a tool that can show the challenge caches of the world on a map. Different filters can be applied.

Tools

The checker script system can be used to create different tools to check for statistics that are not otherwise available at the site. See Tools in the checker system for more information.