"Look what we've done with the Fallout franchise. We've turned an existing franchise into millions of sales. Can we do that again?"
"If we're taking franchises that were big in the late 90s, I wonder if there's a way we can reboot the Thief franchise?"
"Eidos still owns the intellectual property rights to that game."
"Besides, rumour has it that they are working on a new game."
"Still, I really think we could have a go of doing a Thief game well. What if we took the general idea of Thief and changed a few of the mechanics?"
"Well, instead of slowly sneaking up on people and clobbering them over the head, how about we sneak up on people to stab them?"
"That's a start, but it doesn't sound like enough."
"We could change the focus away from stealing. Stealing would be there, but it wouldn't matter as much."
"So what would the goal be?"
"Remember in Oblivion where we assassinated the Emperor at the beginning? Imagine if the Emperor's guards were in on it and could frame the protagonist."
"And from there, the protagonist seeks revenge... I like it. What else?"
"What if, too, we take away the punishment for not being stealth? We make it so stealth can be there for those gamers who crave stealth, but also allow gamers to play it like an FPS."
"But won't that discourage people from using stealth? Why make a stealth mechanic if it's only optional?"
"I know, we'll reward players who use stealth with a different ending - a good ending. And punish players who just kill everyone by giving them a bad ending."
"That sounds a little like Bioshock."
"Bioshock also did cool magic powers, perhaps we can use them too."
"Oh, and we should include zombies because they're the in-thing right now."
"Yes, this is sounding more and more like a game. Let's get on this quick before Thief 4 comes out."
Perhaps Bethesda weren't going out on a limb conceptually, but what's not to love about a game that combines Thief, Bioshock, and the Elder Scrolls franchise?