In playtesting, Arkane found that people just weren’t all that able to go about finishing the mission using their own heads. Without at least some sort of clue, people would just wander about aimlessly, hoping for the mission to complete itself.

“People would just walk around. They didn’t know what to do. They didn’t even go upstairs because a guard told them they couldn’t. They’d say ‘Okay, I can’t go upstairs.’ They wouldn’t do anything, explained Arkane’s Julien Roby."