The original Diablo and its sequel are fondly remembered as some of the best action RPGs of all time – however a Hellfire expansion was released for the original game that has been somewhat lost to time.
The expansion was originally developed and released in 1997 by now-defunct developed Sierra subsidiary Synergistic Software. It was later re-released in 1998 as a bundle with the original game.
Hellfire was not an official Blizzard product, is considered a non-canonical part of the series, and did not carry their endorsement or label (it never has since).
Despite that, since the first digital release of Diablo (via GOG), fans have been asking for the expansion too.
GOG naturally asked Blizzard for permission to re-release the Hellfire expansion, to which Blizzard agreed – but only if it’s included as a free add-on with Diablo purchases on the GOG store.
Here’s a quick rundown on the expansion:
Hellfire offers a non-canonical single-player storyline where players must defeat a powerful demon named Na-Krul who is threatening Tristram. The expansion also adds a Monk class, new weapons and items, new missions, locations, dungeons, and enemies. Hellfire will be accessible while launching the original Diablo.
You can find the original Diablo, now with its Hellfire expansion, here on GOG.