Adventure Game Interpreter
AGI (Adventure Game Interpreter) was the development tool used by Sierra Online to create their early adventure games.
The first King's Quest game originally used a language named Game Assembly Language, or *.gal, by its designer, Arthur Abraham. When its main designer left, Sierra was unable to complete the game, which had been intended to showcase the technology of the IBM PCjr. IBM "donated" its product, AGI, to Sierra to allow development of King's Quest to continue.
When it debuted in the mid-1980s, AGI was innovative and made impressive use of the technology available at the time. Later versions were adapted to use 16 color EGA graphics and the Adlib soundcard.
By the end of the 80s, however, AGI's 160×200 resolution began to show its age and could not compete with newer engines such as Lucasfilm Games' SCUMM, which featured mouse support. In 1990, Sierra abandoned AGI and started using the SCI (Sierra Creative Interpreter) engine for their adventure games.
The AGI system was originally designed for the IBM PCjr and clones. In the 80s it was also ported to other platforms, and some games were released commercially on the Apple II, Apple Macintosh, Amiga and Atari ST. Although there is a Sega Master System version of King's Quest and a NES version of King's Quest V, it's highly unlikely that they use the AGI software system.
List of AGI games
This is a list of Sierra games made in AGI (roughly chronological order). Note that there have been fan companies and other individuals who have produced usually shareware or 'unofficial' AGI games.
- King's Quest: Quest for the Crown (1984)
- King's Quest II: Romancing the Throne (1985)
- The Black Cauldron (1986)
- Donald Duck's Playground (1986)
- King's Quest III: To Heir is Human (1986)
- Space Quest: The Sarien Encounter (1986)
- Leisure Suit Larry in the Land of the Lounge Lizards (1987)
- Mixed Up Mother Goose (1987)
- Police Quest: In Pursuit of the Death Angel (1987)
- Gold Rush! (1988)
- Manhunter: New York (1988)
- Space Quest II: Vohaul's Revenge (1988)
- King's Quest IV: The Perils of Rosella (1988) *
- Manhunter 2: San Francisco (1989)
* King's Quest IV was simultaneously produced and published in both the AGI and SCI formats. The main advantages of SCI are a higher resolution (320x200 rather than 160x200 in AGI), sound card support, mouse support, and a more versatile scripting system. Sierra supposed that contemporary low-end systems would be unable to run the SCI version, thus requiring a 'lighter' version of the game. However, sales figures proved them wrong, and the AGI version was quickly discontinued. Because of its rarity, the AGI version could be considered a collector's item.
Related software
Sarien (Sierra AGI Resource Interpreter Engine) is an open source game engine recreation that can run AGI games. Sarien works on Linux/Unix, Microsoft Windows, Sega Dreamcast, and GP32.
NAGI is an open source AGI game engine recreation for Linux and Windows that is mostly complete and has additional features such as mouse support.
MEKA was the first AGI game engine recreation available to the public. The name is an acronym combining the last names of the authors (Joakim Möller, Lance Ewing, and Peter Kelly), and the word Adventure. It is open source and is only available for DOS.
LAGII is an AGI game engine recreation by XoXus for Linux. It can only play games that are built into it's database, and the compatibility isn't high.
JAGI is an open source AGI game engine recreation by Jens Christian for Linux. It isn't very advanced, but it is very portable.
AGI Studio is an open source program that lets users create games that are based on the SCI0 engine. AGI Studio is designed for Windows. There is a version for Linux called QT AGI Studio (formerly Linux AGI Studio).