At the end of a mission I completed the stats said I killed 9 enimies and 1 civilian, yet my chaos was still low. Doesn't that seem like a little too much lee-way? I did do the mission mostly tending towards stealth however. Does the chaos rating depend more on if you spared the main characters rather than the insignificant guards? Also, does a low chaos rating require less kills on higher difficulty levels? Is there a difference between killing a guard silently and killing a guard in a less stealthy fashion (like sword fight, grenade etc.) when it comes to chaos?

in regards to low and high chaos the mission stats at the end take into consideration the whole of that level you've played. so u mite have killed 9 people but on the level as a whole there cud be 30 + guards so killing 9 isnt a massive amount. i once killed one person in a whole level and it stated high chaos at end of mission and it was overseer cambell who i killed, so maybe killin a main character adds to chaos.

I believe I read somewhere that if you kill less than 20% of the people in a level, you get low chaos. But I'm sure the status of the main target and any hostages matters in some way.

I killed well over 50 people, though none of them were civilians, in my first playthrough, and still got low chaos. Most of them were killed stealthily, and almost no bodies were ever found, so that may have some effect on the chaos rating.

I think so too. When I decided to go for the high chaos ending, I found it hard to do so, had to replay a few levels because I didn't murder enough. And then I have to resist the temptation of hiding the bodies and whatnot, and breaking all the rules I've learned from playing Thief and other stealth games

So yeah, I agree.

One thing i found lacking in chaos is it was too "black and white" there was nothing in the middle like a medium chaos or a med low or med high or anything other then high and low and i felt that although you have mutliple choices not enough of them impacted the ending you still only have 3 endings (low chaos, high where you dont save emily, high where you do save emily) though they could easily make up for that with a dlc that is affected by certain characters being left alive (for example meeting the then alive and deformed pendleton twins who can only write to communicate as a new character)