Once you reach level 50 on any character on your account, any 10 to 49 level characters can use Timewalking Campaigns to choose an expansion for their leveling experience. To do so, interact with the Hero’s Call Board located in Stormwind’s Trade District or Orgrimmar’s Warchief’s Command Board in the Valley of Strength and select “Chromie’s Call.” From here, you’ll be pushed a quest, “Adventurers Wanted: Chromie’s Call” which will lead you to Chromie who awaits adventurers near the Stormwind Embassy to the north-west of the Dwarven District or the Orgrimmar Embassy in the southern-most area of The Valley of Spirits. After meeting with Chromie, you’ll be able to pick a campaign from any past expansion which will scale to your level.
Now just select a campaign, and you’re ready for adventure! Simply follow the new quest pushed to you and travel to the destination listed in the quest’s objective. From there you’ll be able to explore the expansion content as you choose, and can even stay within the content for the entirety of your level-up experience.
Tip: Unsure if you made the right choice or want to explore a different timeline? Simply speak with Chromie who will offer you other expansion timelines or return you to the present.
While using the Dungeon Finder (hotkey: I), you'll be offered dungeons for your selected timeline to keep the exploration of the zone’s story intact. However, if you join a group and different characters have chosen different timelines, you'll be able to enter the queue for dungeons from any timeline represented by the party. If the queue for dungeons within the timeline you’ve chosen takes too long to find a suitable group, you’ll be offered to expand the search to other timelines.
Timewalking Campaigns are available for you to use as soon as your character reaches level 10 or completes the new starting experience, Exile’s Reach. Now, go forth in your journey—your future is waiting for you in the past!