Steven Spielberg originally intended the storyline to be an episode of his TV series Amazing Stories (1985). It was to be about an archaeological dig on a (presumed) alien planet in the far future. Human archaeologists unearth a large structure and an alien statue, which, in a Planet of the Apes (1968)-like twist, turns out to be the Disneyland castle with the Mickey Mouse statue in front of it, revealing the planet was Earth all along. However, the production costs would have been too high, so Spielberg approached LucasArts in 1989 with the idea of making it a video game instead, after being very satisfied with the way Indiana Jones and the Last Crusade: The Graphic Adventure (1989) had turned out. Spielberg and George Lucas came over to LucasArts and would pitch many other ideas over four brainstorming sessions. The story ultimately went through many changes, retaining only a few elements of the old concept. Spielberg later contributed to the screenplay by suggesting several puzzles and situations, and helping out with character development. He finally sent letters of gratitude to all crew members to thank them for their hard work.
The game went through three major versions before it was released. The second version was helmed by Brian Moriarty (who took over from Noah Falstein), and looked a lot like the finished product, but was primarily aimed at adults. Not only was it filled with heavy scientific lingo, philosophical content and creative puzzles, it was also made quite violent and gory, as requested by Steven Spielberg. For example, one of the characters would turn into a bloody corpse after entering a cave with an acid rain, Robbins was to be ferociously attacked by bats, and there was to be an amputation scene featuring lots of blood, requiring a tourniquet. At one point, Spielberg himself suggested a scene where Boston had to electrocute a large aquatic eel in order to obtain the lens from its eye, since it could stun bats; as Boston cut out the lens, blood would splatter all over the screen. However, after receiving much criticism for some particularly violent and bloody scenes in his movie Jurassic Park (1993), Spielberg asked the design team to tone down the mood of the game, so that it would still be appropriate for children. In the end, Moriarty's enthusiasm and ever expanding vision, fueled by Spielberg's involvement, became a bit too ambitious for the technical limitations of the time, so he left the project. Dave Grossman temporarily took over to trim the game's scope, but as he was tasked with fixing and retaining as much as possible without changing anything, he left after several months as well. Sean Clark eventually revived and finished the game.
During its production, The Dig was canceled and re-started three times, leading to three different plot outlines and four changes of project leaders. It lingered in development hell for so long that even Sean Clark, who would finally finish it, initially suggested to just cancel the game altogether. It was mostly because of George Lucas' insistence that development on the game, an initiative of his good friend Steven Spielberg, continued and led to a finished product. During the end credits, there is a "Ghosts of Dig's Past" section dedicated to the many artists, including project leaders Noah Falstein, Brian Moriarty and Dave Grossman, who worked on the abandoned versions.
When looking at his PenUltimate, Boston Low (Robert Patrick) mentions it is a "T-1000 model". Patrick is probably most famous for playing the T-1000 Terminator in Terminator 2: Judgment Day (1991). Later in the game, one of his conversation lines is "Have you seen this boy?", also directly taken from T2.
The game went through three major versions before it was released. The first version was helmed by Noah Falstein, inspired by an original idea by Steven Spielberg that was vastly different from the final result. It would have been a role-playing adventure game, situated in the future on a distant planet named Ozymandias, with ruins of four major cities (on a mountain, an island, a jungle and half-submerged in the sea). The jungle city would have been housed inside a gigantic living creature, genetically designed by the original sophisticated alien inhabitants. Any remaining aliens had since devolved to a primitive state. The player could choose between two very different human astronauts inspecting the planet as the game's main character. This choice would substantially influence how certain puzzles were solved. They would gradually find out that one of the cities waged war on the peaceful other three, making the planet so toxic that all survivors of each civilization were forced to go into stasis, to be revived when the planet became habitable again. The main characters would eventually revive all civilizations, and, with the help of the docile aliens, stop the aggressive tribe from immediately trying to gain control again, by converting them to a peaceful way of life. Unfortunaltely, Falstein had immense troubles of translating all of Spielberg's ideas and story elements into a playable game, so this version was eventually canceled and re-started from scratch by Brian Moriarty, retaining only the basic premise.