Blizzard is bringing back the Joyous Journeys buff, granting players an extra 50% experience boost!
XP Buff (Source)
The treacherous roads of Northrend are filled with icy perils. To aid you on your epic journey, players will be blessed with the Joyous Journeys experience buff*, which will amplify experience gains by a whopping 50% for all adventurers up to level 80! This is the perfect opportunity to complete the leveling of your character, embark on a new adventure, or rally your comrades to join you in your heroic exploits.
For those who wish to control the flow of experience, simply pay a visit to any innkeeper in the capital cities or Dalaran to toggle the experience buff on or off. The Joyous Journey’s experience buff will be available throughout the Ice Crown Citadel content update and until further notice.
*Experience buff not available in modern World of Warcraft® or World of Warcraft® Classic Era.