The Cast Showoff: Reportedly, Sarah using a shotgun one-handed was inserted because Linda Hamilton's pre-film training regimen had made her strong enough to work a pump-action with one hand.
Dawson Casting: An odd case. Edward Furlong was 13. The early scene when the T-1000 is searching the police database shows that John Connor is 10, but as of Terminator 3: Rise of the Machines, he's ret-conned to 13 as of the events of the film. A straighter example with the young man in the arcade who shows the T-1000 where John is. According to Word of God on the commentary, he was a production assistant who looked about 14, but was nearly 30.
Deleted Scene: A lot, many of which were later restored in the extended version. Among them a dream sequence where Sarah Connor fantasizes a meeting with Kyle Reese, The Hero of the previous film who is now of course The Lost Lenore for Sarah. Sarah imagines Reese encouraging her not to give up, even embracing her, reassuring her that he'll always love her before disappearing, giving her the ominous warning "There's not much time left in the world, Sarah." Sarah chases after Reese as he leaves the mental institute where she is being held, and ends with Sarah witnessing Judgment Day.
Dyeing for Your Art: Linda Hamilton is a much more physical presence in this movie than in the previous film.
When Sarah is bludgeoning the nurse who assaulted her with a broomstick, that's Linda Hamilton really whacking the actor. Apparently, he was pretty hesitant to hit Hamilton with a nightstick in a prior scene, which caused a lot of takes of a physically demanding sequence for Hamilton (one that didn't even make the theatrical cut and resulted in her falling hard on her knees on a hard floor many times), and she took out some frustration in return.
Reportedly, Hamilton learned to pick locks so she could do it for real when escaping the mental hospital.
The scene where hospital security guard Lewis dies at the T-1000's hands features twins Don and Dan Stanton; Don is the real guard and Dan is the T-1000 mimicking him.
There is a shot where the T-1000 disguises itself as Sarah to try and kill John. Linda Hamilton's twin sister, Leslie Hamilton-Gearren, plays the role of the T-1000 in the scene. The filmmakers were not aware until production commenced that Hamilton had a twin; the original plans called for complex camera tricks and film editing to achieve the same result. Leslie also plays the "motherly" version of Sarah from her playground nightmare.
Gearren is also used in a Deleted Scene, restored in the extended cut, that appears to show the Terminator in a mirror while Hamilton is working on the inside of his head. This was actually a clever set piece, done entirely without camera effects, through the use of an empty mirror frame, the Hamilton twins (Leslie operating on the Terminator and Linda copying Leslie's moves), and a Schwarzenegger dummy with an open robotic skull (with Leslie operating on the dummy while Linda mirrors the movements with the real Schwarzenegger).
Pixellation: Oops. Word of God says he received a bill for "digital willy removal" for the arrival of the T-1000. It didn't work.
Schedule Slip: The film's DVD debut was originally scheduled for August 26, 1997 (read: Judgment Day) but for some reason (perhaps relating to technical limitations with the then-fledgling DVD format; it was, after all, the first dual-layer disc on the market) got delayed to October 21.
The T-800 inexplicably saying "I need a vacation...", but James Cameron found it so funny he left it in.
In addition, Sarah Connor knocking out the orderly Douglas with a broom, as well as the resulting injury, was indeed real. She, or rather, the actress, did it out of revenge because in an earlier scene the orderly went a bit too easy on her during the acting.note In a scene from the Extended Edition where the two orderlies force Sarah to take her pills, the actor portraying Douglas refused to hit a woman too hard, forcing them to do several takes, and Linda Hamilton to repeatedly fall on her knees on the hard floor, bruising them up. They kept it in for the final cut (no pun intended).
Unintentional Period Piece: Unfortunately for the filmmakers, fashion and music changed radically in a very short time in the early nineties. The grunge and gangsta rap scene replaced the colorful fashions and upbeat music of the early '90s (think hairbands, MC Hammer, and Vanilla Ice) almost overnight. Through most of the film this isn't evident. But Guns n' Roses had a hard fall by the mid-nineties and the two guys who attempt to help John (and nearly get killed for it) are wearing painfully early-nineties fashions.
When Cameron first told Arnold about a sequel in 1985, he said it would feature two T-800s, one of which would become a metal skeleton. When he actually begun working on the second one in 1990, he decided to turn the evil Terminator into the T-1000 instead.
WASP singer Blackie Lawless was considered for the role of T-1000.
Shaquille O'Neal reportedly asked for a role as a black Terminator.
Michael Biehn, who played Kyle Reese in the first film, was originally supposed to be the T-1000 and Cameron would've wrote around it by saying that Skynet managed to get Kyle's DNA and used it for the T-1000, but the idea was binned by the studio when they thought audiences would get confused by this.
Billy Idol was originally slated to play the T-1000, but a serious motorcycle accident in 1990 left him incapacitated and unable to work.
Earlier drafts of the script included many scenes that was ultimately left out in the final script:
Alternate beginning has an extended battle sequence of the future war, with John Connor as the narrator, who mentions Judgement Day happened in 1999. It also describes many different war machines besides the flying and tank H/Ks. It shows the machines shut down, since Skynet has been defeated. It shows the soldiers breaking into the Skynet complex and sending Kyle Reese into the past. The sequence ends with John Connor looking at a storage area holding the Terminators with human skin, he finds a row with identical appearances (the Arnold model), and looks at an empty case (of the Terminator from the first movie) and the Terminator next to it. Then we flashback to Janelle trying to call John in the garage. A version of this sequence was eventually used to open the fifth movie.
A scene which Sarah was forced into shock therapy. She flashback to when she crushed the Terminator in the first film. Then we cut to the scene of the second Terminator's arrival.
Sarah's alternate dream after she was forced into taking the pills. After chasing after Reese, she was ambushed by the orderlies, then the Terminator came and grabbed her, and took her outside, to the playground. The nuclear explosion struck and it ends with the shockwave blasting the skin out of Sarah and the Terminator.
The Gant Camp sequence. A more extended and alternate version of the Salceda Ranch sequence. Travis Gant was the "ex-Beret guy" John mentioned in the film. Here Gant is married to Yolanda while Salceda is instead one of Gant's men. They all find out that Sarah was telling the truth about the Terminators. After John and the Terminator chase after Sarah, the T-1000 came and killed everyone at the ranch. There's also a scene where the T-1000 was listening to a recorded message from Sarah telling John to go to Gant Ranch (Salceda Camp in a rewrite); right before he heads there, a couple of cops came to arrest him when they discover he's driving a stolen police car, then we cut to the T-1000 in the motorcycle.
Similarly, there's a scene which the T-1000 arrives at Salceda Camp. Salceda performs a Heroic Sacrifice by blowing them both, but the T-1000 survives, then he kindly asked the Salceda's family where John is and lets them live. Notably in this draft the family survives, while in the Gant Camp sequence, Jolanda is implied to be killed (and she was pregnant).
Sarah's second dream sequence instead has nuclear missiles coming from beneath the playground, and the blast incinerated the people and Sarah.
Written-In Infirmity: The T-1000's damage from the liquid nitrogen (hinted in the theatrical cut but made clear in the special edition) was due to Robert Patrick having injured his leg.
Linda Hamilton apparently forgot her earplugs for the scene where the T-1000 attacks Sarah, John and the T-800 in an elevator and incurred permanent hearing damage from all the gunshots fired in an enclosed space.
Schwarzenegger commented during an interview that doing the one-handed shotgun flip-cock nearly broke his fingers when he accidentally flip-cocked the unmodified gun instead of the prop gun specially modified to be flip-cocked in that shot.
This was later confirmed by James Cameron on the DVD commentary for the Extended Edition that, yes, Arnie grabbed the wrong gun and had a near Epic Fail.
The biker bar scene was filmed across the street from — and on the night of — where the Rodney King incident occurred.
The biker bar set was apparently so realistic that a female passerby walked in (having missed the camera trucks and film equipment), mistaking it for a real bar. When she saw Arnold Schwarzenegger wearing colourful shorts, she asked what was going on. Schwarzenegger replied that it was male stripper night. Hilarious in Hindsight considering where the T-800 got his clothes in the sequel...
The typical temperature of molten steel from a blast furnace is around 1,800 degrees Celsius. A clever and often overlooked pun on both Terminators present in the film, the 800 and 1000 series, respectively.
Finishing multiball without getting a jackpot in Red & Ted's Road Show prompts Red to say "You missed everything!"
Trivia for the SNES video game:
Creator Killer: This game's shoddy quality and laughable controls and animation was the last game to finish LJN's path to becoming the most notorious and hated publisher of the 8 & 16 bit console eras. Their owner Acclaim, who also had a bad rep, took the hint and terminated the brand with prejudice, only reviving it for one game in 2000.