Saw | Saw II | Saw III | Saw IV | Saw V | Saw VI | Saw 3D | Jigsaw | Spiral | Saw X
- Absurdly Short Production Time: It took 25 days to shoot the film.
- Acting in the Dark: None of the cast were shown the last 25 pages of the script so as to not show them the ending, which had five different versions shot.
- Blooper:
- The "LOOK CLOSER, DETECTIVE MATHEWS" text at the ceiling of the Death Mask's crime scene spells Eric's surname as "Mathews" instead of "Matthews".
- In a blink-and-miss moment, while John is being apprehended, two SWAT officers point rifles with laser sights at him. However, there are four visible laser sight spots on John, and there's no indication or showing that there are any more officers pointing at him.
- Bonus Material: The movie's DVD includes a pseudo-documentary short film titled The Scott Tibbs Documentary. Set a while after the movie's events, it's centered around Scott Tibbs, a band frontman and the childhood friend of Adam from the first movie, who makes a documentary with his band about Jigsaw and eventually builds a Jigsaw-esque trap to see if Jigsaw's method actually works.
- Cast the Runner-Up: Lyriq Bent auditioned for Xavier, but producers didn't want to feed into stereotypes by making the drug dealer character a black man. He reluctantly took the role of Rigg instead — which ended up giving him a big role in Saw IV.
- Descended Creator: In the film's DVD Commentary (and as a response to a fan theory he saw on message boards in the Internet), Darren Lynn Bousman stated that he was the one who played the hooded figure (initially meant to be Jigsaw until the theory of Dr. Lawrence Gordon surviving became Ascended Fanon later in Saw 3D) who's seen placing the key behind Michael's eye in the correspondent video tape. He further said that he hobbled around to give flavor to the figure's movement (as well as to show the progress of Jigsaw's cancer since the first film).
- Dolled-Up Installment: The film's script was developed from a separate story that Darren Lynn Bousman had already written called The Desperate, which was rejected multiple times for being too violent. Once Saw became a Sleeper Hit, the script incurred many comparisons to Saw, and upon finding it, the producers asked if the script could be reworked into a sequel to the film.
- Executive Meddling: The MPAA ordered the original poster
◊ recalled because the two severed fingers forming the 'II'' did not meet the standards for film advertising. It was swapped to keep the fingers but at a much larger size◊ that didn't indicate that they were severed. - Orphaned Reference:
- Obi's tape says he will have to confront the devil. This refers to Obi's scrapped fate of having to reach a second portal at the back of the furnace while crawling through the flames.
- Kerry says something about not wanting Eric to lose his son a second time. This refers to a subplot that was cut from the film, where she and Eric had an affair that led to his marriage falling apart and his wife getting custody of Daniel.
- The Other Darrin: A retroactive example once Saw 3D turned Ascended Fanon the theory of Dr. Lawrence Gordon surviving and being the hooded figure who put Michael Marks' key behind his eye. Thus, the actor who plays Gordon in this film was director Darren Lynn Bousman, replacing Cary Elwes from Saw. It should be noted that before the Retcon, the hooded figure was meant to be Jigsaw himself, so Bousman was replacing Tobin Bell back then.
- Throw It In!:
- Frankie G improvised a different line each time Xavier insults Addison when they're trying to break through the exit door. They went with the take they thought was the funniest.
- Frankie also improvised the bit where Xavier puts the bit of skin he's cut off his own neck into his pocket, whereas the script originally just had him throw it on the ground.
- When Obi pops out of the furnace, Jonas' actor Glen Plummer accidentally got hit in the eye. As a result, you can see Jonas holding his eye in one shot.
- Working Title: This movie is a Dolled-Up Installment, before it was rewritten as a Saw sequel, it was going to be called The Desperate.
