ATLAS and P-body

"These next tests require co-operation. Consequently, they have never been solved by a human. That's where you come in. You don't know pride, you don't know fear, you don't know anything. You'll be perfect."

- GLaDOS

ATLAS and P-body, referred to as Blue and Orange by GLaDOS, are a pair of bipedal robots that appear in Portal 2’s co-operative campaign. They have been created by GLaDOS to complete the most complex tests in the Aperture Science Enrichment Center, uncompleted by any human.

Background
ATLAS and P-body were created by GLaDOS for the "Cooperative Testing Initiative" project just before Chell escaped, to phase out human testing in Portal 2. However, she determined that the act of experimenting on and observing the results of robots performing various tests, as a robot herself, was fundamentally flawed, which is likened to the famous thought experiment of Schrödinger's cat. Thus she determined that for the tests to actually mean anything, it needed a human observer. To add that human element, she needed to find a way for the robots to become more human-like, to the point where they were human enough so that results could be derived from the tests.

Cooperative tests were then set up in a total of 35 Test Chambers in five distinct courses. The first four are based on a specific testing element, while the fifth takes elements from the previous four and adds Aperture Science gels to the equation. They involve the standard teleportation/puzzle tests, and sending the robots to the ruined parts of the Enrichment Center in search of human relics to puzzle together, so that they can learn to become more human, and even learn how to love.

Portal 2


GLaDOS mentions that she had been working on the Cooperative Testing Initiative before Chell escaped, although it isn't clear whether she meant the first time she escaped from the Aperture testing course in Portal, or the second time, when she escaped with Wheatley's help in Portal 2. While Wheatley was in control of the Aperture Laboratories facility, he discovered the C.T.I. and decided he no longer needed to keep Chell and GLaDOS alive for further testing, as the replaceable robots could serve in their place, leading him to try to kill his current test subjects. After Wheatley is forcibly removed from control (not to mention the planet Earth), GLaDOS comes to much the same conclusion, finally giving Chell her freedom (and her original Weighted Companion Cube). Following Chell's exile from Aperture Laboratories, GLaDOS begins testing on ATLAS and P-body. They are sent through a series of test courses designed to prepare them for the final chamber which takes place in the abandoned basement of the facility. Over the course of their testing, GLaDOS tries to drive them apart in various ways, only to fail each time. She eventually concludes that they simply lack the capacity to betray each other. For their final test, ATLAS and P-body are sent to unlock a vault containing hundreds of humans in stasis, since GLaDOS has determined that testing with robots just isn't the same, although she tells them there is still much work for them to do.

Appearance


The robots were designed from scraps. ATLAS' design is based on a Personality Core, while P-body is based on a Sentry Turret. To facilitate their humanization, they were given their own personalities, and clearly anthropomorphic designs and behaviors. For instance, gender-related personalities have been applied to them, with ATLAS being masculine, and P-body feminine (although GLaDOS still uses he to refer to P-Body).

Each robot has its own Aperture Science Handheld Portal Device that bears the color of its user (blue for ATLAS, orange for P-body), as two lines running along the barrel. They can pass through each others' portals, a vital means of completing the tests, and are respawned through Vital Apparatus Vents if destroyed. Duplicate robots are constantly built by automated machines, apparently keeping the memories and behavior of the previous incarnations.

Their heads function independently of their bodies, allowing them to control their limbs even if it is removed. This aspect of their design allows them to play pranks on each other by taking or knocking off their heads.

Personality and skills
As said above, the robots were designed with anthropomorphic personalities to facilitate their humanization. These personalities are expected to develop during the course of the game.

Examples of anthropomorphism go from simple to complex behaviors. For instance, the results of the Aperture Science Collaborative Disposition Test tell that ATLAS is brave and fearless, willing to take on any challenge, while P-body is inquisitive and sensitive, examining the situation with care before proceeding, however, the co-op intro shows the opposite. Both value friendship, making them the ideal testing partners.

Other anthropomorphic behaviors include making gestures to each other to indicate the other what to do or where to go, using some form of speech embodied by an apparently unintelligible robotic chatter (ATLAS having a masculine voice, P-body a feminine), using portals for fun and not only for testing, using some form of laughter, playing rock-paper-scissors, or hugging each other. Co-operative work also requires them to trust each other, and they also undergo tests for that purpose, and eventually will tend to develop a tendency to betray each other like humans would do, and in the end trust each other only 6 seconds longer than humans.

The skills and personality are obviously influenced by the players' behavior toward each other. Tests or achievements require being as much being selfless as being selfish.

Behind the scenes



 * ATLAS and P-body, as well as the Cooperative Testing Initiative, were first introduced during the Portal ARG, in one of the ASCII art images given by the BBS. In that image, actually concept art for Portal 2, ATLAS is holding an Aperture Science Handheld Portal Device, and they hold each others' hands: this gesture is said to be a sign of innocence more than an indication of romance between the two, and also describes the whole co-op idea, that Portal 2 also means playing with a friend. The ARG also revealed through the Aperture Image Format program two images referring to the completion of the trial phase of the Aperture Science Cooperative Testing Initiative, referring to Portal 2’s co-op mode. Their second appearance is at the very start of the "Portal is Free" video promoting Portal being free from May 12 to May 24, 2010, where they can be seen within the isometric offices in a small room on the bottom right. They then appeared in a teaser for the co-op mode of Portal 2 shown at Gamescom 2010, in a dramatized version of an example of co-op gameplay, where ATLAS elbows P-body so that it subjects itself to ATLAS's portal to be sent thanks to momentum to a button located beyond a trap and allowing the completion of the Test Chamber. In the video, they appear to use some form of speech, consisting of computer-like sounds. They then appeared in the full version of the co-op trailer and other variants of it, and weekly videos leading up to Portal 2's release, such as a TV spot, Aperture Investment Opportunity #1: "Panels", and Aperture Investment Opportunity #2: "Bot Trust".




 * Originally, the two Portal 2 co-op characters were to be human females, one being named Mel, the other being Chell. They were replaced by robots when it was noted that playtesters tended to die a lot, thus creating an in-universe reason for the constant respawning, and making them the first playable robot characters in the Half-Life and Portal series.


 * As seen in other concept art images, the two robots have come through several other iterations, including color variants, and more humanoid appearances, with influences from the film Westworld, as the team at some point wanted them to look human and feel robotic at the same time. As seen in more recent concept art, they also originally both had a red eye, later changed to blue and orange for ATLAS and P-body, respectively.
 * When the website ApertureScience.com was updated for Portal 2, the Garden Gnome from the alternate Christmas video was replaced by a nervous P-body.
 * The robot names are apparently a reference to their body shapes, though this has not been confirmed yet. ATLAS may be related to the Titan of the same name, which is often represented as supporting Earth on his back, a task which would be eased by the size of ATLAS' shoulders. "ATLAS" being written in caps, this may also be an acronym of a currently unknown significance. P-body's name, meanwhile, refers to a label on its back describing the robot's 'Frame Type' as 'P'. It may be a pun on "pea body", the robot's body shape somewhat resembling a pea pod.
 * The robots are referred as "ballbot" (ATLAS) and "eggbot" (P-body) in game files.
 * Three custom skins are available for those who pre-ordered or buy the retail version of Portal 2, depending on the place of purchase.
 * Roll Cage (featured in the informational video Aperture Investment Opportunity #2: "Bot Trust"): pre-ordering through GameStop (USA) or EB Games (Australia).
 * Paint Job: pre-ordering through Amazon.de (Germany), Amazon.fr (worldwide) or CDON.com (Sweden, Denmark, Norway, Finland).
 * Antenna Topper: pre-ordering through Fnac (France), Webhallen (Sweden), Alcom (Swiss) or Softridge (Swiss), buying retail version in Russia or CIS.
 * Several unused P-body textures can be found in Portal 2 game files: white dirty, white clean, blue and red, possibly used by placeholder robots model (not existing in game files). The red light can be seen on the textures.

Trivia

 * P-body makes a cameo appearance during Chapter 8. At Test Chamber 15, when Wheatley attempts to make an "exit" for Chell, P-body can be seen opening a door and entering it.


 * In the developer commentary, it is stated that ATLAS was constructed well before P-Body.

List of appearances

 * Portal ARG
 * ApertureScience.com
 * PotatoFoolsDay ARG
 * Portal 2
 * The Final Hours of Portal 2