This seems to map to a value that helps the backend decide when to award challenge points
The numeric "goal". For killstreak challenges, this is the intended streak, for damage challenges, the damage, etc. If there is no goal, this is set to "1"
An incrementing challenge ID
The resolved localization of the challenge (in English)
The description of the challenge. This often describes the challenge best
The title of the challenge. This often has no relevant information about it
The string referencing the localization keys that describe the challenge. These are automatically resolved as Challenge.loc
Seemingly unused; always 0
The reward, in eggs
The challenge "subtype". This is null if it's a challenge that deals damage or involves death
A tier rating that describes how hard the challenge is. Accounts that meet certain conditions are given higher tiers
The challenge "type"
A challenge-specific value that is function-dependant on the values of type, subType, and conditional
A second challenge-specific value that is function-dependant on the values of type, subType, and conditional
Represents the raw challenge data in ChallengeList