List of Portal characters

The following is a list of characters in Portal and Portal 2, both developed and published by Valve.

Chell is the player-character in both Portal games. She is a silent protagonist outside of small grunts during physical tasks. Very little truthful information is known about Chell; while GLaDOS makes many statements to Chell's background and history, GLaDOS herself admits she is unreliable. The only consistent fact that is used through the series is that Chell's parents gave her away. Whether they did it intentionally or not is unknown.

GLaDOS (Genetic Lifeform and Disk Operating System) is a rampant artificial intelligence computer system that controls Aperture Laboratories, and is the primary antagonist for the Portal series. She is voiced by Ellen McLain. She awakens the player-character Chell in the first game, tasking her through the dangerous testing course, but Chell manages to escape and appears to destroy her, though later revealed to have had her personality stored within a black box. Within the second game, Wheatley accidentally reawakens GLaDOS, and eventually convinces Chell to initiate a core transfer to replace her with himself. GLaDOS, placed into a module powered by a potato battery, is forced to work with Chell to depose Wheatley from power before the Aperture facility is destroyed.

Doug Rattmann, often referred to as the "Ratman" is a character in both Portal and Portal 2. He was a former scientist working at Aperture and one of the few who survived when GLaDOS flooded the facility with neurotoxin. In the two games there are various "Ratman dens", where Doug Rattmann has left scribblings and paintings on walls in hidden rooms. Ratman’s full appearance is only seen in the Portal 2: Lab Rat webcomic released by Valve prior to Portal 2's release to tie the story of the two games together. Ratman is the comic’s main character. Prior to GLaDOS' rampancy and the neurotoxin release, Doug Rattmann was once an Aperture scientist. Already skeptical of the computer, the man fled from the gas and kept himself hidden from GLaDOS' view, slowly becoming more insane over an unknown stretch of time. Among the wall scribblings in the Portal dens is the sentence "The cake is a lie", which became an internet meme.

The Lab Rat comic reveals that, despite his madness, Doug Rattmann identified Chell as a rejected test subject due to her high tenacity, and moved her to the top of the queue for testing. During events in Portal, he worked behind the scenes to scribble messages and warnings to Chell on the walls, leading her out of the testing chambers and towards GLaDOS. After watching her defeat the computer, he managed to escape the facility, but returned to assure Chell would be put in indefinite cryogenic storage animation after she was dragged back inside, suffering a serious injury (a shot in the leg from a turret) to complete this. In the last panel of the comic, Doug Rattmann places himself in cryogenic storage animation. His fate by the events of Portal 2 is unclear, though more of the Ratman dens can be found.

Aperture Science Sentry Turrets are sleek, thin stationary robots equipped with machine guns that will fire upon the player upon entering their line of sight. Used as a testing mechanic in Portal and Portal 2, sentry turrets placed in test chambers must be disabled or destroyed in order to progress. Voiced by McLain, turrets possess polite mannerisms in their voice lines, such as "I don't blame you" or "No hard feelings" after being disabled.

Within Portal 2, a series of malfunctioning turrets known as the Defective Turrets also appear. Voiced by Nolan North, these speak with a Brooklyn accent, acting tough but incapable of actually firing bullets or causing damage. They are first introduced in the middle of the Portal 2 single-player campaign in a turret quality assurance line sabotage, where Wheatley instructs Chell to use a defective turret as a template for the automated line to accept defective turrets while destroying functional ones.

An individual turret known as the Oracle Turret appears briefly. Due for incineration, the turret will give cryptic premonitions of future events in the game if rescued by the player. After Wheatley seizes control of Aperture Laboratories in Portal 2, he creates the Frankenturret, an amalgamation of weighted cube and turret only capable of walking around aimlessly. In the ending scene of Portal 2, the player is given an opera performance by a choir of turrets.