Hellfire expansion pack - Definition and Overview

Hellfire is an expansion pack that Sierra Studios produced for the computer game Diablo. It was released in 1997.

Hellfire's storyline occurs as an aside to the main story arc of the original game. It concerns the powerful demon, Na-Krul, who was Diablo's chief minion. The expansion pack adds an additional monk class, two new dungeon tilesets, additional quests, several extra game items, and a number of interface improvements. Two additional characters -- the bard and the barbarian -- can be enabled with a special text-file edit in your Hellfire installation directory. As test characters, these warriors have new skills & attributes, but do not have unique character graphics developed for them.

Hellfire was the only official expansion pack released for Diablo.