Saw Gift

Flashbacks from Saw IV reveal the earliest roots of the series, presenting John Kramer as a successful civil engineer and devoted husband to his wife Jill Tuck, who opened a rehab clinic for drug addicts. Jill lost her baby due to the unwitting actions of a drug addict named Cecil, who fled the scene. John grieved over the loss of his child and distanced himself from his friends and his wife.

John and Jill eventually drifted apart and divorced. After this turn of events, John found himself trapped by his own complacency, until he was diagnosed with inoperable cancer. Extremely bitter over his squandered life, John began observing the lives of others and became even more depressed as he saw those around him squandering the gift of life that he had just been denied. After surviving a suicide attempt where he drove his car off a cliff, John was "reborn", and nurtured the idea that the only way for someone to change is for them to change themselves. He designed a test for Cecil and decided to use the rest of his existence to design more of these "tests" as a form of "rehabilitation" that would change the world "one person at a time". John was soon given the name "Jigsaw Killer" (or "Jigsaw"), so named because he removed a puzzle-piece-shaped chunk of flesh from those who do not escape his traps. John himself states that this name was given to him by the media, and that the cut piece of flesh was meant to represent that these victims were each missing something, what he called the "survival instinct".

Few of Jigsaw's victims are able to survive his brutal tests, which are often ironically symbolic representations of the problems in the victim's life and require them to undergo severe physical or psychological torture to escape.