Elaborating on this in an interview with Mashable, Co-Director Harvey Smith talked about how Lead Level Design Director Christophe Carrier came up with the perfect solution:
He’s the one who recommended, maybe you play as Emily for like half an hour and then you get to this pivotal moment where a dramatic thing happens, and you choose at that point whether to continue with Emily or switch to Corvo. And then you’re locked in.
While the missions will essentially be the same regardless of who you choose, combat is different between the two. “Emily fights with a little more finesse than Corvo does,” Smith said. “Whereas Corvo has the very classic Possession, Rat Swarm, Blink [abilities], Emily has Far Reach, Shadow Walk, Mesmerize… these powers that nobody has heard of.”
Conveyed in the E3 2015 trailer, Far Reach is Emily’s version of Blink where “you send this magic tendril out into the world to pull yourself to a location.”
Smith continued by talking about Emily’s evolution throughout the game:
You can stick to walls, you can yank somebody toward you and assassinate them in mid-air, so you have these synced assassinations in mid-air. It begins to feel different, and it adds momentum. You can run and jump and it has rope physics to it.
Both Emily and Corvo will be fully voiced this time around, and you’ll notice how differently the two characters see the world. “Corvo’s an older guy, he’s coming home for the first time to Serkonos,” Smith said. “Emily is like an empress outlaw on the run, and she’s young, she’s 25. So their perspectives are very different.”
Dishonored 2 releases in 2016 for the PlayStation 4, Xbox One, and PC. Before that, the Dishonored Definitive Edition releases on August 25.
Dishonored 2 Emily or Corvo Choice Happens Early on, Arkane Talks About Their Differences