Actress Allusion: Solid Snake and Johnny Sasaki are reminded of Meryl Silverburgh when they see Olga Gurlukovich. There's a good reason for that. In the Japanese version, Meryl and Olga were both voiced by Kyoko Terase.
Actor Allusion: Dolph ends up being held hostage onboard a stage. He is voiced by Kevin Michael Richardson in the English version, who also voiced Prince John in the Disney version of Robin Hood, where that character had something similar happen to him after he ordered for Robin's execution.note Richardson never voiced John in the film itself. He does, however, voice him in House of Mouse.
Approval of God: While the VR theory was shot down by Hideo Kojima (see below), he included numerous nods of it in Metal Gear Solid 2: Substance, particularly "External Gazer": While testing out Otacon's newest toy, a VR helmet, Snake is tricked into believing he's Raiden and starts to experience bizarre scenarios.
Executive Meddling: Konami execs forced Raiden's name in Japanese to be written using kanji (雷電), instead of katakana (ライデン) like other characters, because ライデン looked a bit too much like a transliteration of "Laden", as in Osama bin Laden.
Flip-Flop of God: The AI who converses with Raiden at the climax of MGS2 is credited as "JFK", but this was later retconned to John Doe.
Jossed: Give the ambiguity of Raiden's perceptions of realty and the bizarre ending, some fans hold that the entire game is a VR simulation gone berserk; the final pitched battle against the RAY army takes place on a platform which is identical to the one in the VR Missions expansion game. As of Metal Gear Solid 4: Guns of the Patriots, this has been Jossed, though it's also been speculated that this interpretation was Kojima's original intention and he merely buckled under fan pressure in between games. *Inception horn*
Meaningful Release Date: At least one trailer pointed out that the game was released during the Chinese Year of the Snake.
The Other Darrin: In the English version of the Secret Theater film Metal Gear Raiden: Snake Eraser, Raiden was voiced by Charlie Schlatter (in other words, Raikov) instead of Quinton Flynn either because he was unavailable or the localizers wanted to make the similarities between Raiden and Raikov more apparent.
Reality Subtext: "[We should] let our children read our sad and messy history by its light," says Solid Snake. While the game was in production, there was a major controversy about the Japanese government whitewashing World War II atrocities in school textbooks.
Talking to Himself: Solidus Snake and Solid Snake are both voiced by Akio Ohtsuka in Japan, and they exchange lines during Raiden's first encounter with Solidus.
The game was originally going to be mastered in North America on September 14, 2001. However, due to 9/11, a sequence where Arsenal Gear crashes through Manhattan was severely chopped down. Instead, the game jump-cuts from Arsenal Gear accelerating down the Hudson River with the music swelling dramatically, to it having already reached Federal Hall.
The Document of Metal Gear Solid 2 reveals a variety of cut content from the game. For example, Snake was supposed to plant C4s on RAY (similar to his work with Philanthropy), not just take pictures. This sequence made it into Metal Gear Solid 3 during Naked Snake's sabotage of the Shagohod factory.
In addition, the Tanker chapter was intended to end with an escape sequence as Snake tries to make it out of the tanker before it sinks, but the sequence was cut because play testers didn't think it was fun enough. Footage of the cut sequence is still used in the main game itself, in flashbacks.
There were supposed to be two additional members of Dead Cell (Old Boy and Chinaman). In Chinaman's case, his boss encounter was in an area that was eventually used for the fight with Vamp.
Originally, there was going to be an unlockable item called the Mantis Mask, which would have allowed Raiden to read the thoughts of NPCs. This sounds suspiciously like it was retooled into the directional microphone.
Originally, Raiden's privates would have been exposed during combat inside Arsenal Gear, prior to meeting Snake, depending on the player's actions. It would have led to a game over.
The scene of Arsenal Gear crashing into Lower Manhattan was cut due to 9/11: It was planned as a pretty brutal sequence, with Ellis Island and the Statue of Liberty being toppled like bowling pins (you can see why it wouldn't fly, even today). What isn't generally known, though, is that Snake was supposed to join Raiden for the finale, battling Liquid Ocelot and Solidus Snake as a crowd of rooting civilians and mounted policemen look on.
Vamp was originally going to be a woman. Due to the introduction of Fortune, however, Vamp's gender was changed during development. Also, he was originally supposed to be, similar to a real life vampire, afraid of the crucifix, although it was mostly due to the trauma he experienced when the church he was attending in Romania was bombed with him and his family in it, where he actually was impaled by one.
The original plan for the plot was for Liquid to have survived the events Metal Gear Solid and be the Big Bad for this game with Snake as the protagonist.