In addition, crafting mats will now be automatically placed in their own designated storage area.
This will free up valuable storage space for weapons and armor, something that has become particularly important in recent years with the popularity of legendary items.
The original idea to commemorate the anniversary was to simply add the classic music, which would play during Adventure mode.
You can see a glimpse of this in some of the images below, although seeing it in motion is what really sells it as a retro experience.
Special rewards and loot will be offered through this event, including portraits, banner, sigils, pets (such a Butcher one), and the game's first helmet-slot Legendary gem.
This won't be available at all times; instead, it'll be a yearly event that's available during January on PC, Xbox One, and PS4.
You enter through a portal in The Old Ruins area, at which point Blizzard says everything "gets crappy," with pixelated visuals, minimal animations, and tinny audio.
With this, players can transition between various builds depending on what they're doing.