John Kramer (Jigsaw) is the main antagonist of the Saw reboot franchise. He is a serial killer who relied on various elaborate death traps for his victims, forcing them to go through extreme pain or trauma in order to survive. His methods of killing are also mean't to teach his victims to appreciate and cherish their lives a lot more than they did.
John Kramer was a successful civil engineer who ventured into property development, explaining his mechanical skills. He was also a devoted husband to Jill Tuck, who ran a recovery health clinic for drug addicts and they were expecting a son named Gideon. John supported Jill in her job, even coming up with the motto "Cherish Your Life" for the clinic. One night while closing down the clinic, Jill was robbed and assaulted by a violent drug addict named Cecil Adams, causing her to miscarry which resulted in Gideon's death. John saw Cecil fleeing with the stolen drugs, so John went and found a bleeding Jill, rushing her to the hospital.
This incident caused John to change his look on life, as he began to realize people can only change themselves. John then went to the local hospital for a checkup, he was informed by Dr. Lawrence Gordon that he has colon cancer and an inoperable brain tumor. Shortly after being diagnosed, John visited the health insurance company Umbrella Health in a desperate attempt to be treated through an experimental drug program, but the company's executive, William Easton, denied him health coverage and caused John to be pushed to suicide.
Utterly depressed, John attempted to commit suicide by driving off a cliff, but managed to survive the suicide attempt and then changed himself. John was sent to hospital after this and while on his hospital bed, John observed people wasting their lives, people he believed to be undeserving and unappreciative of the lives that John has been denied, John wanted to make people appreciate their lives and realize how precious life truly is, one person at a time.
John was recovered from his injuries and then decided to first target Cecil Adams, as he found his life as a lie and that he was wasting it with drugs and being a thief also for killing Gideon. At a Chinese Festival, he saw Cecil taking drugs and stealing so John got two pig masks at the festival. He donned one and used the other to hide a chloroform-soaked rag and put the second mask on Cecil, knocking him out with the chloroform and abducting him without being caught. John placed Cecil in the Knife Chair where he was forced to push his face into the knives in front of him to "bring the ugliness out" and break the trap. Cecil managed to do this but grabbed one of the kitchen knives and attempted to kill John, but John avoided his attacked and allowed him to bleed to death in a box of razor wire he fell in.
John spent the next months of his life observing and planning for his "test subjects", using his former profession to construct devices and traps to test their desire to live, often through ironic means. Placing the subjects in the traps, each victim was left a terrifying message explaining what they did to deserve their fate and how they could escape and survive. Each message was either a chilling, distorted voice on a tape or through his threatening puppet, Billy. John also had a method of overseeing the "game" which is unknowing to the victim.
John found a man who feigned his illness in order not to go to work as a software analyst, so John worn a pig mask and knocked on the door. As Mark Rodriguez Wilson opened the door, John hid, causing Mark to go outside and so John drugged and captured him from behind him. Mark was placed in the Flammable Jelly Trap where John injected him with a slow acting, lethal poison, placed a safe in the middle of the room containing the antidote to his poison, covered the floor with broken glass, covered Mark in a flammable substance with a candle on top of the safe and wrote the combination to the safe on the walls. Mark almost completed his test but accidentally touched the candle, burning to death and John watched via peephole. Once he died, John entered the room and cut a jigsaw out of his body which is supposed to represent he was missing the Human survival instinct. The police eventually discovered his corpse, and as soon as they found the jigsaw piece cut out, they coined the name Jigsaw or Jigsaw Killer.
After Lieutenant Detective Mark Hoffman used a rigged Jigsaw trap to kill murderer Seth Baxter for killing his sister, John had him abducted and placed him in a chair which was connected to a double-barreled shotgun, John claimed that he was not amused of Hoffman framing John for the murder of Seth Baxter. Using the evidence needed and knowledge against Hoffman, he blackmailed Hoffman into becoming Jigsaw's first apprentice, showing him better means of "rehabilitate" their subjects.
Jigsaw and Hoffman both set up the Razor Wire Maze for a suicidal man named Paul Leahy. Hoffman assisted Jigsaw in kidnapping Paul with Hoffman attacking him while Jigsaw sneakingly sedates him. Paul is sentenced to crawl through razor wire and find the exit in 3 hours or else he'll be left to die in the trap. Over time, Hoffman became more willing to help John, providing him with the crucial files of information containing many of the details of the lives, jobs and convictions of various cops and criminals ultimately targeted in the Jigsaw murders.
Jigsaw later abducted a heroin addict named Amanda Young alongside her drug dealer, Donnie Greco, Jigsaw placed her in the Reverse Beartrap and had Donnie heavily tranquilized. Jigsaw instructed her to kill Donnie in order to retrieve the key, so Amanda did this and escaped her trap. Amanda then became a willing yet mentally unstable apprentice to Jigsaw.
John eventually planned to involve three people in one game: Adam Stanheight, Lawrence Gordon and Zep Hindle. Adam was a freelance photographer who watched others live out their lives, Dr. Gordon was a surgeon who was cold, uncaring and unfaithful to his wife and Zep was badmouthing people instead of attempting to improve his own life.
John organized the game so Lawrence and Adam would be locked up in the Bathroom where Lawrence would be forced to kill Adam before 6'o clock or else Zep would be forced to kill Lawrence's wife and daughter, Allison and Diana. John and Amanda set up the Bathroom and John painted his body to look like a corpse.
John posed as a corpse in the game and had Hoffman poison Zep and hand him the instructions of his game as well as the Bathroom's location and a handgun. Amanda also placed hacksaws and Adam's photographs inside a black bag within the toilet tank, a box containing a lighter, cigarettes and a single bullet in one of the walls marked with a X, placed tapes reading "PLAY ME" in the pockets of the two and a revolver and tape recorder in both of John's hands.
The game ended with Lawrence escaping and Zep being killed by Adam along with Diana and Allison surviving. While Zep's tape finished, Jigsaw revealed himself to be the one responsible for the entire incident and is indeed alive, he then locked up Adam in the Bathroom and left him to die as punishment for failing his test.
Nerve Gas House/Eric's Test
Jigsaw then targeted Eric Matthews, his son and the criminals that Eric was responsible for framing and arresting. Amanda was to pose as one of the subjects and was responsible for keeping Daniel Matthews alive and eventually lock him in a safe which was programmed to open in 2 hours.
Jigsaw and Hoffman set up the Nerve Gas House and set up traps including the Magnum Eyehole, Needle Pit, Razor Box and Furnace. Jigsaw then abducted Michael Marks, Eric's informant, and placed him in the Venus Flytrap where he was forced to cut out his eye to retrieve a key and escape. Though Michael failed and was killed by his trap, so Eric investigated with Allison Kerry and then found Jigsaw's lair. Eric, Kerry, Daniel Rigg and a SWAT Team broke into the lair and some officers were killed by a security trap, Jigsaw then waited in his room. Jigsaw tested Eric to simply talk and listen to him, then he could have his son back.
Though Eric failed his test and resorted to brutality, almost killing John and brutally beating him down. John then took him to the Nerve Gas House where he stumbled across many corpses and a pig mask wearing Amanda drugged and knocked him out in the Bathroom. So Amanda left him her own tape without a voice changer and locked him up in the Bathroom as punishment for failing, leaving him to die.
The Final Tests
John became greatly weakened and his health rapidly declined, and discovered that Amanda became a full-out murderer who created inescapable traps for subjects which offered no salvation. In his desperation, John planned to test her and if she failed, make sure she doesn't carry on his work. John planned out his final tests, having Amanda kidnap Lynn Denlon while Hoffman kidnapped Jeff Denlon, Corbett Denlon, Timothy Young, Danica Scott and Judge Halden.
Amanda began acting violent towards Lynn as John gave her a lot of attention, intended or otherwise. Towards the end when Jeff completed his tests and that Lynn succeeded, Jigsaw begged Amanda not to kill Lynn for her own safety. Eventually, Amanda shot Lynn in the back as Jeff entered the room, causing Jeff to shoot Amanda in the neck and she bled to death as John informed her that he was testing her and explained he wanted her to win, but she couldn't and tearfully said "Game Over".
Amanda died and Jigsaw lay in his deathbed, telling Jeff he can rather kill him or forgive him, Jeff claimed to forgive Jigsaw but then brutally used a chainsaw to slash his throat and kill him. Before he finally died, John played a tape and Lynn was killed by her trap because it was linked to John's heart rate monitor.
Jigsaw left a tape in his stomach for Hoffman which Hoffman secretly took and listened to alone. It informed him that his the last man standing and was handed notes to be used for future games including Daniel Rigg's tests, the Fatal Five's tests, William Easton's test and optionally Bobby Dagen's tests.