Muzyka said that the BioWare team has faced the same challenging decisions in building a story, and that having a strong team along for years helps. "These are the difficult choices we make throughout the collaborative process... if it's a rational collaborative discussion, it's very humble, and people are willing to take a better idea," he said.

Muzyka said that the process of building a body of knowledge around an IP can take six months to a year, all with the aim of creating a livable world that feels real.

"It's like an iceberg -- 90 percent of the content created will never be seen by fans," he said. "The tip is the part that's so hard to decide -- what to show?"

So BioWare focuses a lot on the activity chains -- where does the story intersect with player behavior like combat and exploration? "We always try to improve and tighten this so the narrative flow, the pacing is improving," he said.

But building a detailed universe, he continued, is really the key to making the game feel real. The places the player doesn't get to see are what creates possibility and makes the story resonate.

Levine said, "Sculptors chip out a statue from stone. The challenge with games is that you build the rock and THEN take out your chisel... I feel people don't chip enough."