Challenges are optional objectives introduced in Doom (2016) and expanded on by Doom Eternal.
Starting with Resource Operations, each level offers three challenges that may require the player to kill enemies in a specific manner, perform a number of glory kills or find secrets. Each completed challenge awards one weapon point.
After purchasing all upgrades for a given weapon modification (or in the case of the pistol and super shotgun, the weapon itself), a mastery challenge will be unlocked that requires the mod to be used in a particular manner (kill so many of a particular enemy, kill a given number of enemies in one shot, etc.) Successfully completing a challenge will unlock a final upgrade for that modification.
Starting with Cultist Base and ending with Urdak, nearly every level offers three special objectives (such as finding an item, or killing a certain type of demon in a specific way). Each completed challenge awards a Praetor suit point, and successfully completing all three challenges in a level awards a Sentinel battery.
Just like Doom (2016), purchasing all upgrades for a weapon modification will unlock a mastery challenge for that mod, requiring the mod to be used against a particular enemy or to kill multiple enemies in one shot; completing the challenge will unlock a final upgrade for that mod. In the late game, mastery tokens can be found hidden in levels; each token allows one mastery challenge to be bypassed and instantly unlocks the mastery upgrade for that mod.
Mastery tokens are found in:
- Taras Nabad (2)
- Nekravol (2)
- Nekravol - Part II (1)
- Urdak (2)
Weekly challenges are organized as part of the Slayers Club and require being connected to one's Bethesda.net account. As the name implies, they are changed on a weekly basis. Completing them gives bonus XP for events which are used to increase rank and unlock cosmetic items.