Pasted from http://www.mobygames.com/game/unreal/trivia
Contributed by Rúben Alvim (1) on 18.07.2004.
One of director James Cameron's pet projects after Titanic was an epic sci-fi extravaganza called Avatar, much hyped in Hollywood circles at the time and poised to redefine the notion of a truly alien world on the big screen.
The project fell apart some years ago, but the scriptment (a hybrid between a script and a treatment ) by James Cameron still exists. Interestingly, you can find quite a few similarities between it and Unreal:
Both feature a basic plot premise where, by virtue of circumstances mostly beyond his control, a reluctant hero becomes the saviour of the native race of an alien planet forced to mine their land for ore of utmost importance to an invading race coming from the skies. In both cases the saviour is seen by the natives as someone who also came from the skies and is thus initially met with some alarm or distrust only to be later hailed as a pseudo-messiah.
The native race is called "Na'vi" in Avatar and "Nali" in Unreal. The physical description of the Na'vi by Cameron can be visualised as basically a cross between the Nalis' tall, lean, slender bodies and the IceSkaarjs' blueish skin colour patterns, facial features, ponytail-like dreadlocks and caudal appendages.
The Nali in Unreal worship goddess Vandora. The home planet of the Na'vi in Avatar (which the Na'vi worship as a goddess entity) is named Pandora.
In Avatar, one of the most dazzling alien settings described is a huge set of sky mountains, "like floating islands among the clouds". One of the most memorable vistas in Unreal is Na Pali, thousands of miles up in the cloudy sky amidst a host of floating mountains. The main sky mountain range in Avatar is called "Hallelujah Mountains". The main Unreal level set in Na Pali is called "Na Pali Haven". Both include beautiful visual references to waterfalls streaming down the cliffs and dissolving into the clouds below.
The Earth ship in Avatar is called "ISV-Prometheus". One of the levels in Unreal takes place in the wreck of a Terran ship called "ISV-Kran". Even more striking, in the expansion pack Return to Na Pali, the crashed ship the player is asked to salvage is called "Prometheus".
One of the deadly examples of local fauna in Unreal is the Manta, essentially a flying manta-ray. In Avatar, one of the most lethal aerial creatures is the Bansheeray, basically a flying manta-ray. The expansion Return to Na Pali even features a Giant Manta, while in Avatar one of the most formidable predators is a giant Bansheeray, which Cameron dubbed "Great Leonopteryx".
In the two stories (especially Return to Na Pali, on Unreal's end), a plot point arises from the fact the precious ore behind the invasion of the planet ("tarydium" in Unreal, "unobtanium" in Avatar) causes problems in the scanners.
Unreal was in development for several years before its release in 1998. The Avatar scriptment was probably finished as early as 1996-97. Bearing all the above in mind the temptation to start wondering about further suspicious parallels may be quite strong, but in spite of these similarities both titles have few else in common and many aspects actually veer off in wildly different directions. Even so, the coinciding factors can make for an interesting minutia comparison.