Each challenge requires the player to complete cooperative missions under different conditions. Some challenges cover individual co-op missions while others are cumulative challenges for completion of all six normal or advanced missions. Each challenge is a single rank, and upon completion the player earns XP. Unlike most challenges, no titles are earned for completing co-op challenges.
All challenges require the free Outlaws to the End DLC, which is the source of the co-op missions. The normal challenges are available from the beginning (do not need to be unlocked) while the advanced challenges require the player to complete the normal counterparts before being unlocked.
The Journal section of the menu provides a completion bar for each challenge, but does not list which co-op missions have been completed for each challenge. The player should keep track of which missions have been completed without dying in order to plan for a more cautious approach to the remaining missions.