Erik Wolpaw spoke with 1UP’s Mike Nelson recently about some of the creative decisions that went into making Portal 2, how GLaDOS came into existence, how Aperture Science is designed to evoke a certain tone, and how Chell’s gender was based on a coin toss:
For Chell, it was almost literally a coin flip. We had to decide on a gender for the main character, and we quickly picked “female” and moved on to the million other decisions we had to make. There was no agonizing over it or any deeper message; We just really didn’t consider it a big deal. For GLaDOS, we’d worked with Ellen before on Half Life 2, and knew she could do a good “computery” sounding voice. So in that case, the actor came before the character was fully fleshed out and drove the gender decision.
Read the rest of the interview here.