Involves any challenge with resource collection (collect X grenades, collect X ammo boxes)
Involves any challenge with damage (deal X damage)
Involves any challenge with death (die X times)
Involves any challenge with kills (get X kills, get X kills with gun, etc)
Involves any KoTC-specific challenges (stand on coop for X, capture X coops, etc)
Involves any challenge with movement (travel Xm, jump X times)
Involves any CTS-specific challenges (pick up spat, hold spat for X time, gain X kills with spat, etc)
Involves any challenge with time (stay alive for X, play for X)
Possible values for the "type" prop on Challenge