Diablo 1 playable in Diablo 3? Yes please.
Diablo 1 was originally released in December 1996 and to celebrate this milestone, the Diablo 3 team announced a special anniversary event titled “The Darkening of Tristram”.
This event includes a shiny new dungeon featuring all 16 levels of the original Diablo and presented in “glorious retrovision” which mimics Diablo’s original perspective.
This is all included in patch 2.4.3 which is coming out soon. Once that drops, you’ll encounter cultists all over Sanctuary; kill them and you can loot their missives, which will lead you to a portal to the new dungeon.