Bob Heitman

Last updated: January 14, 2026

Overview

Robert Eric Heitman, known professionally as Bob Heitman, was one of Sierra On-Line’s first employees and a pivotal figure in the development of the company’s game engine technology.¹ As co-developer of both the Adventure Game Interpreter (AGI) and its successor, Sierra’s Creative Interpreter (SCI), Heitman helped create the technological foundation that powered virtually every Sierra adventure game from the mid-1980s through the late 1990s.² His work on these engines enabled the creation of landmark franchises including King’s Quest, Space Quest, Leisure Suit Larry, Police Quest, and many others.

Heitman’s career at Sierra began in 1982 as a conversion programmer, porting Sierra’s early graphics adventures to the Commodore 64.³ His technical expertise and understanding of multiple hardware platforms made him invaluable during an era when games needed to run across diverse computer systems. After nearly a decade at Sierra, he left in late 1991 to pursue contract work and eventually founded his own company, Triton Interactive, continuing to contribute to notable games including Ringworld: Revenge of the Patriarch and Star Trek: Judgment Rites.⁴

Career

Early Career

Heitman joined Sierra On-Line in 1982 during the company’s early growth period, initially working as a conversion programmer responsible for adapting Sierra’s Apple II games to other platforms like the Commodore 64.³ This work required deep understanding of both source and target hardware architectures, establishing Heitman’s reputation for technical versatility. In 1985, he took on the significant project of porting Ultima II: The Revenge of the Enchantress to the Atari ST, demonstrating his ability to handle complex game conversions.⁵

His early work at Sierra positioned him to become involved in the company’s most important technical initiative: the development of the Adventure Game Interpreter.² Working alongside Jeff Stephenson, Chris Iden, and Sol Ackerman, Heitman contributed to the creation of AGI, the engine that would power Sierra’s first generation of point-and-click adventure games and revolutionize the gaming industry.⁶

Sierra Years

Throughout his tenure at Sierra, Heitman worked on refining and extending the AGI engine while also contributing directly to game development.⁷ His programming credits span many of Sierra’s most beloved franchises, including King’s Quest, Space Quest, Leisure Suit Larry, Police Quest, Manhunter, and Gold Rush!.¹ This broad involvement gave him unique insight into the needs of different development teams and helped inform the evolution of Sierra’s engine technology.

The pinnacle of Heitman’s Sierra career came with his co-development of the SCI engine in 1988.² This successor to AGI represented a major technological leap, supporting 256-color graphics, improved sound capabilities, and more sophisticated game logic. King’s Quest IV: The Perils of Rosella became the first game to use SCI, demonstrating the engine’s capabilities and setting the technical standard for Sierra’s golden age of adventure gaming.⁸

Post-Sierra Career

After leaving Sierra in late 1991, Heitman contracted with Tsunami Media, where he created the technology behind their games and developed the Passport2 online gaming network.¹ In 1993, he founded Triton Interactive, his own consulting and programming company, which allowed him to work with multiple clients including Interplay, Legend Entertainment, Legacy Software, and Microsoft.⁴

His post-Sierra work included significant projects across the adventure and strategy gaming genres.⁹ He served as game designer for Ringworld: Revenge of the Patriarch, bringing his Sierra experience to a new science fiction franchise based on Larry Niven’s novels.¹⁰ He also contributed as additional system programmer on Star Trek: Judgment Rites for Interplay and as programmer on Shannara for Legend Entertainment Company.¹¹

Notable Works

Adventure Game Interpreter (AGI)

Heitman’s contribution to the Adventure Game Interpreter represents one of his most significant achievements.² Developed in the early 1980s, AGI was designed to power Sierra’s revolutionary graphics adventure games, beginning with King’s Quest I.⁶ The engine utilized all 16 colors of the EGA graphics adapter and allowed players to interact with animated characters in real-time environments. Heitman’s work on AGI helped establish Sierra as the leading adventure game company of the 1980s.

Sierra’s Creative Interpreter (SCI)

The SCI engine, co-developed by Heitman in 1988, represented a generational leap in adventure game technology.² Supporting 256-color VGA graphics, enhanced sound capabilities, and more complex game logic, SCI enabled Sierra to create increasingly sophisticated and visually impressive games.⁸ The engine powered Sierra’s most successful titles throughout the late 1980s and early 1990s, including the later entries in King’s Quest, Space Quest, and other flagship franchises.

King’s Quest IV: The Perils of Rosella (1988)

As the first game built on the SCI engine, King’s Quest IV showcased the technological advances Heitman helped create.⁸ The game’s improved graphics and sound demonstrated what the new engine could achieve, helping Sierra maintain its position at the forefront of adventure gaming technology.

Manhunter: New York (1988)

Manhunter: New York featured Heitman’s programming work within the AGI framework.¹² The game’s unique dystopian setting and gameplay mechanics required creative solutions within the engine’s capabilities, demonstrating Heitman’s ability to push technical boundaries while supporting innovative game design.

Design Philosophy

Heitman’s approach to game development emphasized creating flexible, powerful tools that empowered designers and programmers to realize their creative visions.² His work on both AGI and SCI reflected a philosophy of building robust foundational technology that could support diverse game types and evolve with advancing hardware capabilities. This platform-minded thinking helped establish Sierra’s technical leadership in the adventure gaming market.

His experience porting games across multiple platforms gave him deep appreciation for the challenges of cross-platform development, influencing his engine design decisions to maximize code portability and minimize platform-specific complications.³ This practical understanding of real-world development constraints made his technical contributions particularly valuable to Sierra’s operations.

Legacy

Bob Heitman’s contributions to Sierra On-Line extend far beyond his individual game credits to encompass the technological infrastructure that made the company’s golden age possible.¹ The AGI and SCI engines he helped develop powered dozens of games and established technical standards that influenced adventure game development industry-wide.² His work enabled Sierra’s creative teams to focus on storytelling and puzzle design rather than low-level technical challenges.

The influence of Heitman’s engine work can be seen in the continued interest in AGI and SCI among retro gaming enthusiasts and preservationists.¹³ Projects to reverse-engineer and document these engines have helped preserve Sierra’s legacy and enabled modern players to experience classic games on contemporary systems. His technical achievements remain relevant to game development history and continue to be studied by those interested in the evolution of adventure game technology.

Games

Year	Game	Role
1984	King’s Quest: Quest for the Crown	Conversion Programmer
1985	King’s Quest II: Romancing the Throne	Programmer
1986	Space Quest: The Sarien Encounter	Programmer
1986	King’s Quest III: To Heir Is Human	Programmer
1987	Leisure Suit Larry in the Land of the Lounge Lizards	Programmer
1987	Police Quest: In Pursuit of the Death Angel	Programmer
1987	Space Quest II: Vohaul’s Revenge	Programmer
1988	King’s Quest IV: The Perils of Rosella	System Programmer
1988	Leisure Suit Larry 2	Programmer
1988	Manhunter: New York	Programmer
1988	Gold Rush!	Programmer
1989	Space Quest III: The Pirates of Pestulon	System Programmer
1989	Manhunter 2: San Francisco	Programmer
1992	Ringworld: Revenge of the Patriarch	Game Designer
1993	Star Trek: Judgment Rites	Additional System Programmer
1995	Shannara	Programmer

References

Footnotes

1. MobyGames - Robert Eric Heitman — Career profile and complete game credits ↩ ↩² ↩³ ↩⁴

2. AGI Wiki - Bob Heitman — SCI engine development and Sierra career ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

3. Sierra Wiki - Robert Eric Heitman — Early career and Commodore 64 conversions ↩ ↩² ↩³

4. Adventure Game Fan Fair - Robert Heitman — Post-Sierra career and Triton Interactive ↩ ↩²

5. MobyGames - Ultima II Atari ST — Atari ST port credits ↩

6. AGI Wiki - Adventure Game Interpreter — AGI development history and credits ↩ ↩²

7. RAWG - Bob Heitman — Programming credits across Sierra titles ↩

8. MobyGames - SCI Engine — SCI engine history and first game ↩ ↩² ↩³

9. Edenwaith - Reverse Engineering AGI — Technical analysis of AGI ↩

10. MobyGames - Ringworld: Revenge of the Patriarch — Game designer credit ↩

11. MobyGames - Shannara — Programmer credit ↩

12. MobyGames - Manhunter: New York — AGI programming credits ↩

13. ScummVM - SCI Engine — Modern preservation of Sierra engines ↩