John Kramer, more commonly known by the moniker "Jigsaw," is a notorious killer and the central figure of the Saw film series. He kidnaps those whom he feels are wasting their lives and puts them in death traps as a mean to teach his victims a lesson. His traps always include a means to allow his victims to escape death, but in order to do so, the victims will inevitably suffer from physical and/or psychological torture. Jigsaw is well-spoken, intellectual and takes pride in taunting others of their misery. Jigsaw's earlier traps are fairly simple; in the first Saw film, he merely handcuffs two people in a room and demands that one of them sever their own foot off. Later films, however, feature much more elaborate setpieces.
The source of Kramer's motivation stems from his struggle with a terminal illness. Though he struggles to allow his life to continue, he finds fault in others that engage in behaviors that endanger their own lives or that make light of the lives of others. Though he dies in the film Saw III, associates and proteges that serve his cause continue his work through the rest of the film series. His plans are meticulously calculated, as he crafted schemes prior to his death that play out as he had desired long after his passing. Both Saw and Saw II: Flesh and Blood take place prior to his death, and he serves as the antagonist of both games.