Bit of a train of thought incoming here, hope it's not too rambling.
So this topic is not new, but it is something that has been on my mind a lot as of late. It is a fact that violence is the predominant form of interaction in games. Some see this as a problem, some do not. Personally I'm somewhere in between. I don't have a problem with violence as such, but the dissonance between what some games try to convey with their story and the fact that the protagonist is mercilessly slaughtering hundreds of people is often immersion-breaking. There are also a lot of people that simply doesn't want to kill people as entertainment, even if they would enjoy the bare game mechanics of the thing.
However, reducing the amount of violence is not a trivial task, since violence - as I see it - is a natural and easily accessible source of conflict, and conflict is really the important thing here. The simple interaction of pointing a crosshair at something/someone and launching a projectile at them enables a whole host of emergent experiences with almost an infinite amount of permutations: Are you moving, is the target moving, is the projectile affected by certain rules, terrain considerations, ammunition conservation, awareness of the surroundings etc. You trying to accomplish this essentially simple task of delivering an object to the face of another person trying to do the same to you provides ample opportunities for strategy and excitement.
Now, I believe an argument can be made that "violence" and "conflict" are naturally connected, and that doing away with one without affecting the other is not neccessarily possible. However, mortal violence should certainly be possible to at least minimize.
To my mind there would be two main ways to reduce the lethality of gameplay:
1) Replace the actual killing with something less direct.
In Arkham Asylum you don't technically kill a lot of people (if any? don't remember the details), but it is still pretty violent. I think it would be quite possible though to create a context where the form the violence takes is less direct and the resolution of combat is trapping the enemies in a net or similar (just an example, there are probably more elegant solutions). The animations could emphasize the decreased lethality by consisting of a lot of evasive maneuvers, feints and other moves that are not actual damaging hits to the body of the opponent.
In the end though, this is still fighting, and even though it might reduce the sociopath factor story-wise, would probably still not attract the kind of people who doesn't want violence in their games.
2) Invent a new conflict metaphor that does not consist of two entities trying to physically overpower one another.
I don't know of a game mechanic with the same simplicity and modularity as physical combat, but the ideal would be to find a mode of interaction where competition can be as fierce and strategy as deep as with a system based on violence, but that has a completely different context. It doesn't need to be a "realistic" approach, it can be completely abstract, but a mechanic that could replace violence in games taking place in the "real world" would of course be great.
Thoughts? I could of course be completely missing that such a thing already exists; if anyone knows of a game that solves this problem I'd love to hear of it. Also, if you feel I'm completely off the mark please say so. I've tried to make solid some simmering thoughts I've had lately, but I'm not sure I succeeded.