In Demon's Souls it was possible to kill all the NPCs, and I had to take great care not to kill them by mistakes (the R2 button having a tendency to get pressed whenever I put down my controller). And if you did hit a NPC even by mistake, he will turn hostile for the whole play-through.
As Dark Souls is a spiritual successor to Demon's Souls, I'm wondering whether the developer kept that element of gameplay. Is it possible to kill the NPCs in Dark Souls? Do I need to take care not to hurt them? If they are killable, what is the impact on the game, apart from their disappearance?
I could try to hit one of them, but as the game autosave after almost every modification of the world or character state, I prefer not to risk it.
Best Answer
You can kill NPCs in Dark Souls, just as you did in Demon's Souls. Some people kill Lautrec early on, for example, to obtain his very useful ring. If you ever accidentally harm a NPC, they will be hostile towards you, but you can "absolve" your sins at the NPC "Oswald of Carim" in the Church after the Bell Gargoyle fight to make them unhostile. The cost is Soul Level x 2000. Some covenants will also become hostile if you dishonorably leave them (abandon covenant without use of Oswald, betray their rules, etc.), which is also something that can be absolved at this NPC.
Unless you kill Oswald, you can always resort to this method to make the NPC's like you again (note that this won't revive them however if you killed them).
You might miss out on some story/sub-plots, but you should still be able to complete the game having killed all the NPC's that you are allowed to kill. It is hard to say for certain what the impact on the game will be as there are so many NPC's in the game with different functions.