Before development of GLaDOS had begun, Erik Wolpaw was writing the script for the video game Psychonauts, where they went around the office, finding people to provide voices to the words until they could add the final voices to the game. Once they ran out of people, however, he began using a text-to-speech program. According to Wolpaw, people found the lines funnier than they were worth. He commented that "no amount of writing is funnier than this text-to-speech thing reading it".He became bitter about that, stating that he would leverage this and use it to his advantage. The creation of GLaDOS began with a discussion between the Valve team and Wolpaw on the narrative restraints they had to deal with. When they were designing the game, they found that they did not have enough time or staffing to use human characters, due to the amount of animation work and scene choreography involved.
|GLaDOS went through several redesigns before artists settled on the final anthropomorphic shape. Early concepts featured a floating brain and a spider-like appearance|