The Jedi Engine was a game engine developed by LucasArts.
It is rumored that Jedi was a product of reverse-engineering the Doom engine to find out how to build their own. Jedi, was in the end more advanced than the Doom engine, containing features such as rooms over rooms, polygonal objects, haze and fog and the ability to look up and down. It also allowed designers to construct overlapping sectors ("room-over-room") to create multi-story buildings, bridges, and similar structures; earlier first-person shooter engines, such as Doom, do not support this ability. The Jedi Engine does not support perspective correction when looking up and down.
Dark Forces' level geometry was based on sectors, which were in turn defined by a series of walls. Each wall could be "adjoined" to one other wall, creating a link between two sectors. Even though each wall could only be adjoined once, a number of "tricks" were utilized to give the illusion of a more fully 3D environment. Every sector was able to have a "second altitude" — an invisible platform at a given height above the sector's floor that the player could stand on; by positioning 3D objects appropriately, level designers could create the illusion of a bridge or elevated platform. Adjoins could be changed during gameplay, enabling the creation of lifts with a single door that opened onto multiple floors. Another function allowed the player to fall through the floor of one sector into a sector immediately below, with the illusion of continuity. Dynamic level features such as elevators, doors, switches, horizontally moving platforms, and flowing water were coded in an INF file. Manipulating the INF code allowed for in-game effects, such as a radio conversation when an objective is reached.
Many of the key data files in Dark Forces were actually plain text files, allowing fans to decipher the formats and write tools to edit them. These have been used to create a wide variety of new levels for the game. Many of the same fans have gone on to create tools and editors for the later games in the series; and at least two, Yves Borckmans and Don Sielke, joined LucasArts to work on Dark Forces II.
In 2002, a team of fans began the Dark Forces Mod project, planning to remake the game utilizing the Quake III engine used in the latest sequel, Jedi Knight II: Jedi Outcast (later adapted to Jedi Knight: Jedi Academy when it was released). Later, they announced that they would be ending the project, and posted a final release containing full remakes of the first six levels of the game. However, an effort to remake the remaining levels is underway as of April 2008.