ATLAS and P-body

Portal 2 is slated to include a full-length co-op campaign separated from the singleplayer campaign with Chell, also consisting of tests supervised by GLaDOS, the player characters being two yet unnamed bipedal robots.

Overview



 * One of the robots is to be modified from a Personality Core, the other from a Sentry Gun.


 * Very little is known about them so far, but Valve is considering making one masculine (probably the Personality Core-based) and the other feminine (probably the Sentry Gun-based).


 * Each robot is to have its own Aperture Science Handheld Portal Device, the capacity to transport through the portals created by the other, and spawn each time it is killed.


 * The robots were created by GLaDOS after the events of Portal, where she had gained a mistrust for humans. GLaDOS, however, determined that the act of experimenting on and observing the results of robots performing various tests, as a robot herself, is fundamentally flawed. Erik Wolpaw likened this to the famous thought experiment of Schrödinger's cat, though the exact nature of GLaDOS' rationalization is unknown so far.

Behind the scenes



 * The two robots 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, the robot made from a personality core is holding an Aperture Science Handheld Portal Device, and they hold each other's hands (this gesture is apparently a sign of innocence more than an indication of romance between the two, and also refers to the 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 the Personality Core robot elbows the Sentry Gun robot so that it subjects itself to the other robot'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.


 * 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 that constant respawning.


 * As seen in other concept art images, the two robots have come through several other iterations, including color variants, and more humanoid appearances. They also originally both had a red eye, later changed to blue and orange for the Personality Core and the Sentry Gun, respectively.


 * The ASHPD used by the robots appears to shoot purple portals instead of the original orange, while the original blue remains.

Trivia

 * The masculine robotic voice heard during the retconned end of Portal is unrelated to these robots, as it is the voice of the Party Escort Bot, originally planned to appear at that point, but removed from Portal's original release.


 * These two robots are also unrelated to the Military Android mentioned in Portal, as they are built from scraps, and appear several hundred years later.

List of appearances

 * Portal ARG
 * Portal 2