Blizzard has announced that it is going to be celebrating 20 years of Diablo starting on the 31st December with cross-franchise events.
Diablo originally released on the 31st December 1996 for Windows PC followed by a Mac and PlayStation release in 1998. In the dungeon crawler set in the Kingdom of Khanduras, located in the world of Sanctuary, we were first introduced to the Lord of Terror.
The announcement reads
Starting soon, you can experience special in-game events and goodies in Diablo III, Heroes of the Storm, Hearthstone, Overwatch, StarCraft II, and World of Warcraft to celebrate a few of the things we love about Diablo. These events and items will only be available for a limited time, so be sure to check them all out before they’re gone.
The post goes on to give a small hint of what we can expect each game to offer
Diablo III: Recapture the feeling of your first play through of the original Diablo with The Darkening of Tristram tribute event. Venture through a reimagined version of the original cathedral in Diablo III and keep an eye out for some familiar items.
Heroes of the Storm: The battle for the High Heavens continues, and a new Diablo-themed portrait is up for grabs! Can you emerge victorious on this hectic new brawl map?
Hearthstone: In this Tavern Brawl, a hooded stranger awaits, holding a grim deck in his hands. Will you unravel the secrets surrounding this dark wanderer?
Overwatch: Bring the battle for Sanctuary into the fight for the future with in-game sprays representing your favorite Diablo III classes—along with a new player icon modeled after the Lord of Terror!
StarCraft II: Put the Lord of Terror to work for you with a Diablo-themed worker portrait.
World of Warcraft: Strange things are afoot in the world of Azeroth as denizens of Sanctuary cross over into an unfamiliar world.
The exact timing of when the events will occur and for how long wasn’t given, however, if you keep your games up to date and connect on and shortly after the 31st December, you’ll surely be able to try out the celebratory content.