BioShock Infinite's Elizabeth isn't a support character; she's a computer-controlled co-protagonist, according to developer Irrational Games. During the studio's panel at PAX East, the company explained all the hard work it put into making Elizabeth a believable AI companion that still lets players enjoy the game at their own pace.
The panelists began by showing the "Creating Elizabeth" behind-the-scenes video that Irrational released last week, and then went into further detail as they referenced parts of the video.
"The big thing for us was finding out how to make her your partner," said John Abercrombie, Elizabeth's lead programmer. He explained that the studio looked at how partners move: Usually, they move together, but the most difficult part about designing Elizabeth was that video game players are entirely unpredictable. Some take their time, and others sprint through. So Elizabeth will stay with you in general, but if you want to wander off and explore, said Abercrombie, "she'll find a way to entertain herself."
Amanda Jeffrey, the level designer for Elizabeth's "brain," said Irrational had to "make sure that the things that would be interesting to any other human person are interesting to her as well." So they set her up with an "impeccable awareness" of the world using virtual tags for her, in the form of eye icons in the design code; the more icons there are on a particular object, the more "interesting" Elizabeth will find it.
"Elizabeth will find a way to entertain herself"
According to Abercrombie, the way the developers designed Elizabeth was to set her up with a "brain" that gives rise to human behavior, instead of building in specific canned reactions.
"There's some really magical moments that come out of that," he said.
Ken Levine, creative director at Irrational and the game's lead writer, pointed out that while writing a game is a task with known parameters — a three-act story, building out characters — in designing Elizabeth, there were situations where it was impossible to know where the player would be or what was going to happen.
"Doing a game like this is like ... writing a scene where the lead actor is a psychopathic alcoholic," said Levine.
"But that's the joy of it," he added, discussing the interactions between Elizabeth, a creation of Infinite's designers, and the player. "You have to respect the player and love the player, and not fight against them. ... You've got to kind of embrace that lunacy."
"it's like writing a scene where the lead actor is a psychopathic alcoholic"
Drew Holmes, another writer on BioShock Infinite, brought up how important it was to make sure there was a consistency to Elizabeth from all sides — writing, voice acting, motion capture, animation and AI — because if the player stops believing in her, then "we might as well go home." The relationship between Elizabeth and the player character, Booker DeWitt, is the crux of Infinite, and Irrational couldn't just build it with story; it had to support it through gameplay as well.
"Our biggest goal was to make her feel like a partner in combat," said Abercrombie. In Infinite, Elizabeth will occasionally throw you health or a weapon when you're on the ropes. According to Levine, that interaction used to be much more mechanical — you had to look at Elizabeth and press a button, then wait for her to toss you assistance — but Irrational realized that it had to be seamless in order for it to feel believable and spontaneous.
A major part of how Elizabeth comes across is her performance, which comes to life courtesy of voice actress Courtnee Draper and motion capture performer Heather Gordon. Gordon said her theater background was a great help, since she had to make Draper's vocal performance come through in Elizabeth's body language. And the panelists showed a video in which DeWitt's voice actor, hurled verbal abuse at Draper in order to get her in the right frame of mind for a scene in which Elizabeth was crying — Draper compared it to Method acting.
"The default for any sidekick character in a game is annoying," said Jaffrey, eliciting laughs from the packed house. Irrational hopes no one will say that about Elizabeth.
You can read our review of BioShock Infinite here.