Portal: Chell

Although Chell's origins are unknown, she was definitely among the people present during GLaDOS' activation in 200-, as GLaDOS locked down the facility immediately afterward; information revealed in Portal 2 implies that Chell was the child of an Aperture scientist because one of the "Bring Your Daughter To Work Day" science projects is signed by her. The project board mentions an ‘ingredient from dad’s work’ also, with an Aperture logo illustrated nearby. According to the psychological profile in her personnel file, Chell is "abnormally stubborn" and refuses to give up, no matter how daunting the challenge. Due to this, she was rejected as a test subject, but Doug Rattmann altered the testing order, having correctly guessed that Chell's extreme tenacity might allow her to defeat GLaDOS. Chell's Test Subject Application Form states that she refused to answer the essay question and instead answered in binary. The binary can be translated to "The cake is a lie."