On the Following Scale, where do Dishonored's NPCs fit in terms of intelligence?

1- Skyrim- "My friends are dead and I've been lit on fire recently, time to sit down for a sweetroll."

2- Assassin's Creed- "They pay us to yell at people, not to catch them."

3- Metal Gear- "I keep waking up with darts in my ass, better be cautious for a few minutes."

4- Deus Ex: HR- "He's here, we're going to be legitimately concerned for a decent amount of time."

5- Real World- "Suspicious package? Evacuate the building and send backup."

Is it possible to switch from an aggressive, action approach to a stealth one mid mission? Will NPCs relocate based on alerts and alarms? How many sweetrolls can a drunken whaler eat before vomiting?

4.They look for you if they see or hear something weird,and that last for some time.

Lol i liked your description for metal gear

I played it for a couple of hours over my friend's house since he got the game early. I was playing on Normal and I would say #4 matched the AI's intelligence the most. The AI was more aware than I expected them to be and I do recall them changing up their patrol after becoming suspicious. Sometimes they would even bring another guard along to help out before returning to their original post.

Guards have 4 levels of alertness, 0, 1, 2, and 3. Once it goes up to two or so, it won't go back down to 0, it'll remain on 1 or so. So somewhere between 4 and 5 on your great scale.

I don't believe the guards act like they do in Metal Gear because I heard that once someone is knocked out they stay out for the duration of the mission so you don't have to worry about them getting back up and alerting people.

lol great descriptions.....if only games were somewhere between your real life and choice 4 options.

I believe the AI for guards is very similar to Thief's. In there, they reacted to suspicious noises and seeing you, as well as bodies, camera/turret alerts (in Thief 2),
civilian distress, and occasionally things missing/out of place. They would call out, alerting other guards in vicinity, and then systematically search for you, including
opening closed doors and combing through the rooms. Once alerted, they seemed to become more sensitized to noise and would trigger much more easily next time.

Oh and I love OP's description for Skyrim

Best description ever, had to say it.

Indeed, this is what I understood from the stealth system as well.
When you alert them once they'll search for a limited amount of time, but they will never stop being suspicious.

That describes Skyrim's detection system perfectly, as that has actually happened to me before.

This always makes me laugh

http://www.youtube.com/watch?v=lHbF9ynGZV0