Doom Eternal events

Doom Eternal includes an event system via which a time-limited series of challenges are put forward for earning cosmetic rewards, including Slayer skins, weapon skins, and profile badges and titles. Experience is earned toward the items currently available both by completing the current weekly challenges and also simply by playing portions of the game, especially levels of the single-player campaign and Battlemode matches, with a fresh play-through rewarding the most points. Most but not all events have had 15 total levels to progress through, unlocking 15 distinct items, one per level (not including any additional items unlocked by master collections). Completion of master collections, the top tier of player skins, is also driven by earning cosmetic experience points.

A linked Bethesda.net player account and an active Internet connection are required for participation in events and earning of experience points. Loss of connection during a level or match may negate points that were otherwise earned.

Tips
Replaying missions from the mission select menu is of limited use for earning experience, as some levels will grant no experience at all while in this mode. Important exceptions exist, however: Hell on Earth will grant 10000 points for every play-through regardless of items collected or completion percentage. Sentinel Prime and Final Sin also grant points on every play-through.

Keeping a throw-away file that can be deleted and restarted at will is the fastest way to earn points. Aiming for 100% level completion will ensure the largest bonus. Excepting challenges that request a specific skill level, most challenges can be completed on any skill, and skill does not appear to influence the amount of points earned via completing levels.

Some challenges, such as "Complete a mission on Nightmare skill or higher", will not actually mark as complete until the start of the next game state, such as returning to the main menu. The awarded points and any possible unlocked cosmetics will appear at that point.

Though weekly challenges can be completed during them, no experience points are directly rewarded for simply playing Master Levels or Horde Mode.

Boosters
Up to three players can be followed as boosters. A small fraction of XP earned by booster players will also be earned by the people following them. Booster experience is redeemed by pressing the indicated button or key ("R" by default on keyboards) while viewing the event challenges screen.

Historical changes

 * After update 2, the experience bonus for defeating empowered demons was removed.
 * A bug existed where 0 points would sometimes appear to be rewarded when they were actually successfully given, but this was only a ever a cosmetic defect which was eventually repaired.
 * At launch, the additional bonus for completing half or all of the weekly challenges was not properly awarded to players on Steam. This was repaired shortly after release.

Double XP periods
Occasionally (approximately once a month) a weekend or full week will be dubbed a "Double XP" period. During these periods of time, all cosmetic experience points earned, except those gained from boosters, will be doubled. Double XP periods have so far included: