In search of a new, more devastating, weapon, the Russian military began work on the development of cyborgs - superhuman robots built for the purpose of causing destruction. The first step in production was the prototype model of what was to become a line of military robots, which were to be named "Jack". With the project a success, Jack robots were put into mass production, one of which was entered into the King of Iron Fist Tournament. On learning of this, the Prototype Jack was entered into the tournament by Heihachi Mishima to face the main Jack. Despite his increased power, Prototype Jack was ultimately destroyed by Jack, after which he was repaired and later updated by the captured Dr. Bosconovitch. After being remodeled and learning new abilities, Prototype Jack was entered into the second tournament as a rival to the upgraded Jack robot, Jack-2. Despite his improved abilities, Prototype Jack was once again unsuccessful in defeating his rival, this time being permanently destroyed.
Prototype Jack is an aggressive character, determined to grow stronger and smarter in order to destroy all of his opposition. While being silent in battle, with the exception of generic grunts and growls, outside of battle Prototype Jack is very vocal of his thirst for strength and intelligence, and would frequently practice his newly-learned abilities to the point of perfection, to ensure he would never again be defeated.
As a prototype model, Prototype Jack's appearance lacked the finesse of the main line of Jacks, lacking the human-like arms and torso, instead having his robotic frame visible and tools (pincers and a drill) in place of arms. This version of Prototype Jack did have the humanoid head, albeit it more rustic with noticeable damage, and legs, although one boot was replaced with a metal prosthetic, of the main Jacks. After being remodeled, Prototype Jack gained his new, more distinctive look. He now looked more like the main line of Jack robots, although he lacked the skin-like finish, instead having a shiny, metallic finish. He also now has a noticeable rotating hand, something which was expanded upon in later releases, allowing him to spin at the waist also.
Main Article: Prototype Jack/Outfits
The original build of Prototype Jack lacked the appearance of any real outfit, wearing only green camouflage pants and leaving the rest of his robotic body exposed. His second outfit appeared to be a bright metal exoskeleton or suit of lightweight body armor, giving him a Robocop-like appearance. After being remodeled for Tekken 2, Prototype Jack received the same generic outfit of camouflage pants, tank top and combat boots worn by the main line of Jack robots. While these Jacks sport a distinctive Mohawk hairstyle, Prototype Jack differed by wearing his trademark sunglasses and military cap.
The prototype for Jack was developed in Russia. Since it was just a step in the production, the skin was removed from the mecha. Prototype Jack (or P. Jack, for short) was built only for power, so his power capacity far surpasses that of the completed Jack. The tournament's sponsor, Heihachi Mishima, has entered P. Jack into the contest in order to pit him against Jack.
After the first King of Iron Fist Tournament, the remains of the first Prototype Jack unit (a first-stage model of the final Jack model) were repaired after almost being destroyed by Jack's rampaging combat abilities. Upon reactivation, P. Jack complained that his alter-ego had received a refit, and he repeated his complaint until his fuel ran out. Now resting in Kazuya Mishima's laboratory, P. Jack was left untouched for months before a back-up fuel supply reactivated him, and once again he began his constant pleas for a new look. To quiet him, Kazuya gave his captured scientist, Doctor Bosconovitch, the task of remodeling the robot.
With a cunning memory change, the doctor managed to convince P. Jack that his new body afforded him superior protection to Jack's, despite it being only a hat and sunglasses. Kazuya is currently goading P. Jack, demanding more programmed maneuvers in time for The King of Iron Fist Tournament 2. Having repeated his fighting moves over and over (to such an extent that the doctor disconnected P. Jack's voice box), P. Jack now feels his next encounter with Jack will have a much different conclusion.
Ending Description: Prototype Jack traverses a tunnel and emerges from the shadows into a chamber with a vertical opening. P. Jack turns on the boosters in his legs and rises upward, into the sky. As he flies away, he explodes and three screws drop back onto the ground.
In Tekken: The Motion Picture, three Prototype Jack robots are programmed to protect the labs in which Lee Chaolan and Heihachi Mishima had their test subjects hidden. There comes a point in time where the three Prototype Jacks and Jack-2, along with Lei Wulong, have a battle in the middle of the lab.
Prototype Jack appeared in Tekken Tag Tournament as a playable character.
Prototype Jack appeared in Namco X Capcom as an enemy character. He first appears in Chapter 14, along with a second Prototype Jack, as part of Waya Hime's army when she attempts to ambush Bravoman and Jin Kazama.
Prototype Jack appeared as a playable character in Tekken Tag Tournament 2, sporting the same look he received in Tekken 2 and the original Tekken Tag Tournament. His fighting style is very similar to Jack-6's, although he has a slightly different moveset.
Ending Description: A large Prototype Jack is being built, when a Prototype Jack walks toward to it and stares at it while the body of the larger robot opens and some steps descend. P. Jack enters into the stomach of the robot and sits down at a control panel, activates the robot, and prepares to launch with a countdown while the other construction Prototype Jacks leave the perimeter. Just as the giant P. Jack launches, a construction Prototype Jack rushes in carrying a large screw, desperately waving to the pilot in an attempt to get him to abort the (incomplete) giant P. Jack's launch. The pilot, however, misinterprets the worker's actions as a simple good-bye wave, and does a thumbs up. The construction Prototype Jacks are left to watch helplessly as the giant P. Jack launches, rising high into the air before exploding, after which three screws fall back into the hangar.
All Jack robots embody the huge, slow and powerful fighter archetype: they need only a few solid hits to destroy an opponent, but they're very slow and their limited moveset can get predictable, so they require good timing. Jacks deal good damage and possess good pokes and throws, but the real advantage comes from the long range of many of their attacks - most of their punishers are able to hit from afar.
In Tekken Tag Tournament 2, Prototype Jack returned with a moveset nearly identical to Jack-6's. There are some differences between the two, mainly with Prototype Jack utilizing his spinning limb related moves while Jack-6 possesses extendable arms, but their core gameplay is essentially the same.
While other characters utilize the Martial Arts, what Jack robots do is best described as "using brute force to annihilate the opponent", and their fighting style is listed as "Brute Force" accordingly. Prototype Jack is no exception.
- Prototype Jack is the only Jack model who doesn't have plutonium blood (his is gasoline).
- P. Jack is also the only Jack robot that has competed in more than one tournament in the Tekken universe, despite the fact that there is a large difference between his appearance in Tekken and Tekken 2.
- Prototype Jack was destroyed by Jack-2 in the second tournament, as detailed in his Tekken 2 ending.
- Unlike the other Jack models, Prototype Jack is fitted with a rocket booster, built into his leg. P. Jack's internal support system can provide up to three "detonations" to the booster.
- His arm and body are somewhat "loose", as he can spin his hand freely without limitation.
- In Tekken Tag Tournament 2, If the player leaves Prototype Jack alone for about six seconds, he will shut down and reboot himself.
- Prototype Jack's Tekken Tag Tournament 2 ending is a re-imagining of his Tekken 2 ending.
- Prototype Jack, along with Jack-2, Gun Jack and Jack-6 are the only Jack robots to appear in more than one game.