Diablo: Hellfire

Last updated: January 27, 2026

Overview

Diablo: Hellfire is the only official expansion pack released for Blizzard Entertainment’s groundbreaking 1996 action RPG Diablo.¹ Released on November 24, 1997, this single-player expansion was developed not by Blizzard North, but by Synergistic Software, a division of Sierra On-Line.² The expansion introduced a new playable character class—the Monk—along with two new dungeon tilesets, additional quests, new items including oils and runes, and a host of interface improvements that players would come to appreciate.³

The expansion’s storyline centers on Na-Krul, a powerful demon who once ranked highly in Diablo’s hierarchy before turning on his master.⁴ When a sorcerer unknowingly performs a ritual that releases Na-Krul unto the town of Tristram, the player must venture into the demon’s lair to stop this new threat.⁵ Despite being designed as an optional, off-the-beaten-path addition to the original game’s content, Hellfire became Synergistic Software’s most financially successful release.²

The expansion’s development was notably contentious, with Blizzard North imposing numerous restrictions on what Synergistic could include.⁶ Most significantly, Hellfire shipped without Battle.net support, making it a single-player-only experience—a surprising omission given that Diablo was one of the most popular multiplayer games of all time.⁴ Despite these limitations and a rushed development cycle, the expansion generally received favorable reviews from gaming publications at the time and has since been preserved through digital distribution, being included as a free add-on with Diablo purchases on GOG.com since June 2019.²

Game Info

Developer: Synergistic Software¹ Designers: Kirt Lemons, Donald Tsang, Peter Watje, Jim Edwards, Mike McMillen⁶ Publisher: Sierra On-Line¹ Engine: Diablo engine⁴ Platforms: Windows¹ Release Year: 1997 Series: Diablo Protagonist: The Hero (customizable class) Sierra Lineage: Sierra Affiliate

Story Summary

The narrative of Hellfire begins when a sorcerer, conducting an arcane ritual in the depths beneath Tristram, unknowingly releases the demon Na-Krul from his ancient prison.⁵ Na-Krul was once Diablo’s chief minion, a demon of tremendous power who had served in the Lord of Terror’s hierarchy before turning against his master.¹ The sorcerer manages to seal the doors before Na-Krul can fully escape into the world above, but the threat of this newly awakened evil looms over Tristram.⁵

The player, having already faced the horrors beneath the cathedral in the original game, must now venture into an entirely new dungeon complex—the Hive and the Crypt—to confront Na-Krul in his subterranean lair.³ These new areas feature distinct visual themes: the Hive presents an organic, insectoid environment teeming with new monster types, while the Crypt offers a more traditional undead-filled tomb setting.⁵ The dungeons are designed to integrate seamlessly with the original Diablo experience, though they can be avoided entirely if players choose not to engage with the expansion content.⁵

It is worth noting that Blizzard Entertainment did not consider Hellfire’s storyline canonical to the Diablo universe, and its events were not taken into account during the development of Diablo II.³ This lack of official recognition contributed to Hellfire’s somewhat contested status among fans, though the expansion’s gameplay additions and quality-of-life improvements have earned it a dedicated following over the years.³

Gameplay

Interface and Controls

Hellfire retains the point-and-click, isometric gameplay that defined the original Diablo, presenting players with procedurally generated dungeon layouts to explore and loot.⁷ The expansion introduces several welcome interface improvements that enhance the overall experience. Most notable among these is the jog toggle feature, which allows players to run around town quickly—a significant quality-of-life improvement given how frequently players must return to town and how spread out the various merchant characters are.⁸

Additional interface enhancements include new spells designed for convenience: one spell highlights floor objects, making loot easier to spot against the dark dungeon backgrounds, and another teleports the player directly to the nearest staircase.⁵ These additions addressed common complaints about the original game, where loot could be difficult to spot as it blended with the scenery.⁷ The Search spell in particular became essential for many players, with one reviewer noting “I really can’t imagine playing the game without it.”⁷

Structure and Progression

The expansion integrates directly into the base Diablo experience, adding its content as optional areas that players can explore alongside the original sixteen-level dungeon.⁵ The new dungeon settings feature distinct tilesets and enemy types that provide visual and gameplay variety:¹

• The Hive: An organic, insectoid dungeon environment featuring new bug-like monsters and a distinctly different atmosphere from the cathedral and caves of the original game.
• The Crypt: A traditional undead-filled tomb setting that adds new skeletal and spectral enemies to battle.

The expansion also includes additional quests that expand upon the lore of Tristram and its surroundings.¹ Because of its design, Hellfire’s dungeons can be avoided entirely, allowing players to experience the original Diablo content without engaging with the expansion material if they prefer.⁵

Puzzles and Mechanics

Hellfire introduces the Monk class, the only new character class that Synergistic Software was permitted to add to the game.⁶ The Monk offers a unique combat style focused on martial arts and staff weapons, providing a different gameplay experience from the Warrior, Rogue, and Sorcerer classes available in the original game.⁹ The expansion also contains two hidden character classes—the Barbarian and the Bard—which were left in the game code but require players to edit a Command.txt file to access them.³

New item types significantly expand the equipment options available to players. Oils can be applied to items to affect their statistics, while runes can be placed as traps to damage enemies.⁵ The expansion adds a new page of spells, new affixes for weapons and armor, and new shrines that can provide various bonuses—though some shrines could have negative results with unclear text, a design element that frustrated some players.¹⁰ Diablo himself receives a boost to his strength and power in Hellfire, providing an additional challenge for returning players.⁵

Reception

Contemporary Reviews

Diablo: Hellfire generally received favorable reviews from gaming publications upon its release, though critics noted significant shortcomings.³ GameSpot awarded the expansion a 7.5 out of 10, with reviewer Desslock noting that “Hellfire fails to provide as compelling an experience as Diablo, but does provide a good quantity of new monsters, items, spells, and settings.”⁴ He particularly criticized the lack of multiplayer support as “an especially surprising omission considering that Diablo is one of the most popular multiplayer games of all time.”⁴

PC Games magazine gave Hellfire an A- rating, with Barry Brenesal’s review published on February 9, 1998.⁶ Computer Games Strategy Plus also covered the expansion, with Cindy Yans reviewing it on January 16, 1998.⁶ The expansion was recognized as a finalist for Computer Gaming World’s 1998 Best Add-On award, indicating industry acknowledgment of its quality despite its limitations.⁶

Critics generally agreed that while Hellfire offered more of the addictive Diablo gameplay, it lacked the atmospheric effectiveness of the original.³ GameSpot’s review concluded with qualified praise: “Hellfire is definitely more of the same, but that’s not necessarily a bad thing, considering that Diablo was GameSpot’s 1996 Game of the Year.”⁴

Modern Assessment

Modern assessments of Hellfire tend to view it as a worthwhile addition for Diablo enthusiasts, despite its rough edges. HowLongToBeat users give the expansion a 72% rating, with reviewers noting its value for fans of the original game.⁸ One user review states: “If you are already planning on playing through the first Diablo game, there is absolutely no reason you should ignore the Hellfire expansion.”⁸

The Cynical Gaming Blog offers a positive retrospective assessment, calling Hellfire “an excellent addition to the unique real time rogue-like (sort of) classic rpg we know and love.”¹¹ However, other retrospective reviews are more critical. Klardendum’s review concludes: “Hellfire, though… I’m glad I’ve finally played it, but I do not recommend playing it,” citing poor design and tonal inconsistency.¹⁰

Phenixx Gaming awarded the Diablo/Hellfire bundle an 8.5 out of 10 in their 2020 retrospective, praising the package as “a masterwork of sound design, particularly when it comes to the music.”⁷

Aggregate Scores:

• GOG.com: 4.6/5 (2,655 reviews) – for Diablo bundle including Hellfire⁹
• Metacritic: 8.6/10 User Score (39 reviews: 82% positive, 15% mixed, 3% negative)¹²
• HowLongToBeat: 72% Rating⁸
• GameFAQs: 8/10 (user review by TerrisUS)¹³

Development

Origins

Following Diablo’s enormous success as GameSpot’s 1996 Game of the Year, there was significant market demand for additional content.⁴ However, Blizzard North made the decision to focus their efforts on developing Diablo II rather than creating an expansion pack for the original game.⁴ Sierra On-Line, viewing this as “leaving money on the table,” pressed for an expansion to capitalize on Diablo’s popularity.²

The expansion development was enabled through corporate relationships—both Blizzard Entertainment and Sierra On-Line were subsidiaries of parent company Comp-U-Card International (through Davidson & Associates), which allowed Sierra to proceed with the expansion despite Blizzard’s objections.⁶ This corporate interference created a lack of cooperation between the subsidiary companies and set the stage for a contentious development process.⁶

Production

Development of Hellfire was handled by Synergistic Software, a Sierra division, with Blizzard North serving as executive producers.² The project faced significant constraints from the outset, with Blizzard North imposing numerous restrictions on what content Synergistic could include. Series creator David Brevik later noted that “there was a lack of communication with the developer team Synergistic, who didn’t follow the design documents that him and his team provided.”²

The development timeline was extremely compressed, with various sources indicating the expansion was completed in approximately six weeks to four months.² This rushed schedule contributed to many of the expansion’s issues, including problems with pathfinding algorithms for ranged-attack monsters and the failure to carry over many bug fixes from Diablo patches.³ The single character class Synergistic was permitted to add was the Monk; the Barbarian class was specifically vetoed by Blizzard North to preserve exclusivity for Diablo II.⁶

Development Credits:⁶

• Designers: Kirt Lemons, Donald Tsang, Peter Watje, Jim Edwards, Mike McMillen
• Composer: Matt Uelmen (original Diablo music)

The internal conflict resulted in what Wikipedia describes as “a lot of frustration among Synergistic employees and a weaker expansion than Synergistic was willing and able to deliver.”⁶

Technical Achievements

Despite the challenging development circumstances, Hellfire introduced several technical improvements to the Diablo experience. The jog toggle feature for faster town movement addressed one of players’ most common complaints about the original game.⁵ New spell functionality, including the Search spell that highlights floor items and the teleportation spell for quick staircase access, demonstrated thoughtful quality-of-life improvements.⁵

The expansion added compatibility with the original game’s SVGA graphics while maintaining the 256-color palette that defined Diablo’s atmospheric visuals.¹ The two new dungeon tilesets—the Hive and the Crypt—required significant art development to create environments that felt distinct from the original game’s cathedral, catacombs, caves, and hell areas while maintaining visual consistency.⁵

Technical Specifications

System Requirements (Windows):¹

• Operating System: Windows 95, Windows 98, or Windows NT 4.0
• Processor: Intel Pentium 60 MHz or better
• Memory: 16 MB RAM (8 MB minimum, 16 MB for multiplayer in base Diablo)
• Graphics: SVGA-compatible graphics card, 256 colors capable
• Sound: Sound Blaster compatible sound card
• Storage: 150 MB hard disk space
• CD-ROM: 2X CD-ROM drive
• DirectX: DirectX 3.0

Macintosh Requirements:²

• System: Power Macintosh or compatible
• Memory: 8 MB RAM with virtual memory
• Operating System: System 7.5 or higher
• CD-ROM: 2X CD-ROM drive

Modern Digital Version (GOG.com):⁹

• Operating System: Windows 10 or 11
• Processor: 1.8 GHz
• Memory: 2 GB RAM
• Graphics: 3D graphics card compatible with DirectX 9.0c
• Storage: 810 MB
• Features: High-resolution support via aspect ratio-correct upscaling

Cut Content

A significant amount of proposed content was vetoed by Blizzard North during development.⁶ The Barbarian class, which Synergistic had developed, was specifically prohibited to maintain exclusivity for Diablo II.⁶ Both the Barbarian and a Bard class were left in the game code but hidden, accessible only through editing the Command.txt configuration file.³

Additional cut or hidden content includes:²

• The Theo Quest: A hidden quest given by a little girl near Adria’s shack
• The Cow Quest: A hidden quest featuring a character called “Complete Nut” wearing a cow suit
• The Wandering Trader: A character that was removed during development
• Various Easter eggs: Multiple Easter eggs were removed during the development process

Version History

Version	Date	Platform	Notes
1.00	November 24, 1997	Windows	Initial retail release2
1.01	Unknown	Windows	Bug fixes; multiplayer disabled in this patch11
GOG Release	June 5, 2019	Windows	Released as free add-on with Diablo purchase6
Battle.net	January 29-30, 2024	Windows	Added to Battle.net launcher2

GOG.com Patch History:⁹

Update Date	Notes
December 13, 2024	Hotfix: Fixed regression with unresponsive Shift key preventing stationary attacks
December 2, 2024	Updated GOG.COM DirectX wrapper, fixed launch crashes, fixed DEP crashes
November 13, 2024	Validated stability, verified compatibility with Windows 10 and 11

Technical Issues

Hellfire shipped with several technical problems that were never fully addressed. The expansion had no Battle.net support, making online multiplayer impossible.³ Furthermore, playing Hellfire could interfere with the ability to play the original Diablo online—changes made while playing Hellfire would not transfer to online characters.⁵

The expansion was incompatible with the Macintosh version of Diablo, limiting its audience to Windows users.³ Many bug fixes implemented in patches for the original Diablo did not carry over to Hellfire, and Sierra only released one patch that fixed a small number of Hellfire-exclusive bugs.³

Gameplay issues included problems with pathfinding algorithms for ranged-attack monsters, making certain encounters more frustrating than intended.³ The Barbarian class (when accessed via the hidden code) suffered from a rage ability that one reviewer described as “basically suicide.”¹¹ Players could also become stunlocked when surrounded by enemies, with limited options for escape.¹⁰

Modern players may experience additional issues including mouse problems, DEP crashes, and launch failures on contemporary systems, though GOG.com has released updates addressing many of these concerns.⁹

Easter Eggs and Trivia

Despite Blizzard’s restrictions, Hellfire contains several hidden features and Easter eggs that dedicated players discovered:

• Hidden Character Classes: The Bard and Barbarian classes can be unlocked by editing the Command.txt file in the game directory, adding secret character options that were officially cut but left in the code.³
• The Cow Quest: A hidden quest featuring a character called “Complete Nut” dressed in a cow suit, accessible through configuration file modifications.³
• The Theo Quest: A hidden quest given by a little girl who appears near Adria’s shack when enabled.³
• Cornerstone of the World: A special tile that allows players to transfer items between different save files, essentially creating a shared stash system years before this became a standard feature in action RPGs.²
• Title Removal: Hellfire removes the “Diablo” title from the main menu entirely, renaming itself simply to “Hellfire”—a rebranding that struck many players as odd.⁷
• StarCraft Dungeon: One of Hellfire’s dungeons was criticized for strongly resembling environments from StarCraft, though some fans defended this aesthetic choice as fitting the dark Diablo setting.¹¹

Voice Cast

Hellfire uses the original Diablo voice cast and features full voice acting throughout.⁵ The expansion maintains the atmospheric voice work that helped define the original game’s tone, including the iconic town NPCs and quest givers.

Character	Notable Quote
The Butcher	”Ahh… fresh meat.”13
Deckard Cain	”Stay awhile and listen…”9

Legacy

Sales and Commercial Impact

Despite the contentious development process and lack of official Blizzard support, Hellfire became Synergistic Software’s most financially successful release.² The expansion capitalized on Diablo’s enormous popularity, providing additional content for a player base hungry for more dungeon-crawling action. However, Hellfire was not included in the Diablo Battle Chest compilation; instead, it received its own separate Diablo/Hellfire bundle release in 1998.³

Collections

Hellfire has appeared in the following compilations and digital releases:

• Diablo/Hellfire Bundle (1998): Physical retail release combining the original game with its expansion³
• GOG.com Digital Release (June 5, 2019): First digital distribution, included as a free add-on with Diablo purchase⁶
• Battle.net Release (January 2024): Added to Blizzard’s official launcher alongside Diablo²

The GOG.com release was particularly notable as Diablo had been the most voted game on the GOG.com wishlist for years before its eventual release.⁹

Fan Projects

The modern Diablo/Hellfire community has developed several projects to enhance the classic games:

• DevilutionX: An engine port that provides quality-of-life improvements including native resolution widescreen support, modern control options, and cross-platform compatibility.¹⁰ This fan project has become the recommended way to experience the original games on modern systems.

Related Publications

• Original Game Manual: Included with retail release, providing backstory and gameplay instructions⁹

Critical Perspective

Diablo: Hellfire occupies a unique position in gaming history as an officially licensed expansion that was never fully embraced by its parent franchise’s creators. The expansion demonstrates both the opportunities and pitfalls of corporate-mandated development, where business interests pushed for content creation despite the original developers’ focus lying elsewhere.⁶

The expansion’s legacy is complicated by its non-canonical status—Blizzard explicitly did not consider Hellfire’s events when developing Diablo II, effectively rendering the expansion a curiosity rather than a meaningful part of the franchise’s ongoing narrative.³ Yet for players seeking more of the addictive gameplay loop that defined the original Diablo, Hellfire delivered exactly what was promised: additional content, quality-of-life improvements, and new character options that extended the life of a beloved game.⁴

From a historical perspective, Hellfire represents an interesting case study in the relationship between publishers and developers during the late 1990s. The corporate maneuvering that enabled Sierra to produce the expansion over Blizzard’s objections would become increasingly difficult as intellectual property rights and developer control gained greater respect in the industry.⁶ That the expansion succeeded commercially while facing internal resistance speaks to both the strength of the Diablo brand and the quality that Synergistic Software managed to achieve despite significant constraints.

Downloads

Purchase / Digital Stores

• GOG.com – Included free with Diablo purchase
• Battle.net – Available through Blizzard’s official launcher

Gameplay Duration⁹

• Main Story: 13 hours
• Main + Sides: 17 hours
• Completionist: 28 hours
• All Playstyles Average: 16.5 hours

Series Continuity

Diablo: Hellfire exists as a standalone expansion to the original Diablo, adding optional content that players can explore alongside or instead of the base game’s dungeons. While Sierra On-Line published the expansion as an official product, Blizzard Entertainment has never recognized its storyline as canonical to the Diablo universe.³ The events involving Na-Krul and the new dungeon areas were not referenced in Diablo II or any subsequent games in the franchise.³

The expansion integrates seamlessly with Diablo’s existing content, allowing players to access both the original sixteen-level dungeon beneath the cathedral and Hellfire’s new Hive and Crypt areas in a single playthrough.⁵ Characters, items, and progress carry between the original content and expansion areas, though playing Hellfire prevents online Battle.net play and changes do not transfer to online characters.⁵

• Previous: 1996 - Diablo
• Next: 2000 - Diablo II

References

Footnotes

1. Computer Hope – Hellfire – Release date, developer, publisher, system requirements, expansion features, Na-Krul description ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

2. Diablo Wiki – Diablo: Hellfire – Development history, system requirements, patch notes, hidden content, commercial success, Battle.net release date ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴

3. Diablo Archive Wiki – Diablo: Hellfire – Canon status, technical issues, hidden content, pathfinding bugs, bundle information ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹

4. GameSpot – Hellfire Review – Review score, multiplayer criticism, Na-Krul background, Game of the Year reference ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

5. RPGWatch – Diablo: Hellfire – Release date, gameplay features, story details, Battle.net limitations, dungeon design ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷

6. Wikipedia – Diablo: Hellfire – Designer credits, composer, awards, development conflicts, hidden classes, GOG release, review scores ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷

7. Phenixx Gaming – Diablo Hellfire PC Review – Review score, interface observations, title removal, Search spell importance ↩ ↩² ↩³ ↩⁴ ↩⁵

8. HowLongToBeat – Diablo: Hellfire Reviews – User ratings, town running feature, modern assessment quotes ↩ ↩² ↩³ ↩⁴

9. GOG.com – Diablo – User ratings, system requirements, patch history, gameplay duration, wishlist status ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹

10. Klardendum – O Tempora: Diablo Hellfire – DevilutionX mod, gameplay issues, retrospective assessment ↩ ↩² ↩³ ↩⁴

11. Cynical Gaming Blog – Diablo Hellfire Review – Retrospective assessment, StarCraft dungeon controversy, multiplayer patch, hidden classes ↩ ↩² ↩³ ↩⁴

12. Metacritic – Diablo Hellfire Bundle – User score aggregate, review breakdown percentages ↩

13. GameFAQs – Diablo Hellfire Bundle Review – User review score, Butcher quote, gameplay longevity assessment ↩ ↩²