This is serious issue in Skyrim. Tod promised every NPC is killable but he lied. You cannot kill 7/10 of people. I mean, you even cannot kill inn keepers even if they aren't related to quest. I think it was something that if they have childrens you cannot kill them. How stupid is that ? You cannot wipe the stormcloak camps beacause the leader is allways immortal etc...

We all like to have mod where you can kill every single NPC game has. If it is possible there would be some text if he/she was related to some quest. like in fallout, you could kill everyone but if he/she was related to quest later on game notified you.

Thank you

Just gonna throw this out there, but are you suggesting killable children as well?

Why not? First thing I'm going to make. Its a simple flag on every character. If "essential" has a script attached to keep them from dying completely, I would think you can erase everything about that and replace it with either nothing, or a box on death similar to Morrowind's "With this character's death the thread of prophecy has been severed, etc etc"

The system that keeps important characters alive in skyrim might be more complex...for example, I had one of my followers with me, and she is for the most part, completely invincible, surviving being thrown 1000's of feet into the air by a giant, being eaten by a dragon, and even me beating her senselessly as a werewolf. However, on a few occasions, I have accidentally shot her with a sneak attack with my bow, and she has died (being able to be looted and everything). I'm not sure why she is invincible at some times, and yet not others...

I agree, this is important for the "open world" concept. Even if it breaks things, or perhaps especially so.

It's handling those broken things smoothly that creates a headache. I'm certain we'll see some good attempts at freeing us from this issue in the near future, if past history is any guide.