Originally, 'Tom Clancy' rejected the idea of Sam Fisher having trifocal goggles, stating that goggles with both heat vision and night vision are impossible to make. The creators argued that having two separate sets of goggles would make for awkward gameplay and convinced Clancy to allow it.
According to the OpSat data, some of the equipment on the oil-rig in the third mission is made by a company called "Weylanda" and some is made by a company called "Yutani." In the "Alien" movies, the "Company" for which Ripley, Burke and many others work is named Weyland-Yutani.
Unlike most next-generation games, Splinter Cell does not use motion-capture technology. All of Sam Fisher's moves are animated. The creators felt this would give Sam a more "fluid" range of motion.
When Sam Fisher is in Myanmar, he has to give the code phrase "It's a bright cold day in April" to an informant, taken from the opening words of George Orwell's novel "1984" ("It was a bright cold day in April and the clocks were striking thirteen.")
On the first level, the training mission, you can reach the upper lookout room behind your starting position and talk to Anna Grimsdóttir. If you knock her out, you are fired and instantly made a mission failure.