File "challenges.xml"

Resource-Folder: Using this file in a resource folder of a mod will replace the original file.

Content-Folder: Using this file in a content folder will add new challenges.

With REPENTOGON, some attributes have specially mod support capatibilites added to them, see below:

Variable-Name	Possible Values	Description
unlockachievement	string	Sets the achievement(preferably a modded one using the name of the achievement) to unlock when the challenge is completed
startingitems	string	This now supports modded items by using the names of the items instead of the ids. Same format as in vanilla, a comma separated list of values
startingitems2	string	This now supports modded items by using the names of the items instead of the ids. Same format as in vanilla, a comma separated list of values
startingtrinkets	string	This now supports modded trinkets by using the names of the trinkets instead of the ids. Same format as in vanilla, a comma separated list of values
playertype	string	This now supports modded characters by using the names of the items instead of the ids
hidden	boolean	Anything but "false" would result in a hidden challenge that wont show up in the menu
achievements	string	Same as vanilla, comma-separated list (without spaces) of achievements required to unlock the challenge, you can use achievement names for modded achievements
lockeddesc	string	Hint to display instead of the challenge name when its locked, the default phrase is "LOCKED :(" (yes, it includes the sad face)

More Info

For more information about this xml, check the original docs entry here.