Reverse Beartrap

One of the most infamous traps, to the extent that it was used on promotional posters for the first film. It is the most common trap, as Canonically, 5 people have been tested by it, only one person falling victim to it.

Saw (Short)
Original Idea: The Reverse Bear Trap was used in the original Saw short film, attached to a character named David. The scenario played out the same as the later version, with David escaping from the contraption seconds before it went off.

Saw

Amanda Young was put in the Reverse Bear Trap, and accidentally set it off by pulling a wire. She was able to remove the beartrap seconds before it went off.

Saw III
The Reverse Bear Trap was later shown in Jigsaw's lair in the third movie, again on a mannequin head, where it was examined and set off by Lynn Denlon.

Saw VI
At the end of the sixth movie, as part of Jigsaw's final request, Jill puts Hoffman in a modified version of the reverse bear trap with seemingly no means of escape; however he was able to get free from the chair by smashing his hand with the front of the trap, and by placing the reverse beartrap between two bars on a window, prevented it from opening up all the way, and was then able to remove it. He did not survive unscathed, however, as half of his lower jaw was mutilated.

Saw 3D
While investigating the evidence room, Hoffman comes across The Reverse Bear Trap 2.0. He considers it for a moment, but dismisses it for the original Reverse Bear Trap. He takes it and places it on Jill's unconscious body. He clamps it onto her jaw and straps her wrists to a chair. She awakes and he starts the timer. He stands by the exit of the room and watches the timer tick down it's final seconds while Jill struggles against her bindings. The timer hits zero and the RBT snaps open, taking Jill's head with it. Hoffman walks out of the room satisfied, with a mimicked "Game Over".

Victims

 * Jill Tuck (dead)
 * David (alive)
 * Amanda Young (alive and dead in Saw III)
 * Mark Hoffman (alive and dead in Saw: The Final Chapter or Saw 3D)
 * David Tapp (alive and dead in Saw: The Video Game)

Saw: The Video Game
The main character of the game David Tapp awakens in a bathroom with the reverse bear trap on. Following the on-screen icons on how to unlock it, David Tapp escapes. He doesn't use a key in order to unlock it, and it is explained in Saw II: Flesh & Blood that he can unlock a reverse bear trap without using a key due to studying the device many times.

Some people around Whitehorse asylum can be seen wearing Reverse Bear Traps who attempt to kill Tapp due to a key that is inside him which will free them. Tapp can activate the trap by attacking the person.

Tapes
The RBT has also been in costume stores all around the world 

Appearances

 * Canon (1 short, 3 films, 1 game)
 * Saw (short) (First appearance)
 * Saw
 * Saw: The Video Game
 * Saw III
 * Saw VI
 * Saw 3D
 * It should be noted that even though The Reverse Bear Trap is one of the only Saw Traps to be featured in more than one of the series' films, it has only ever claimed one victim, Jill Tuck (Saw 3D), and that was because Hoffman rigged it so that Jill couldn't escape.