Neonchameleon
Legend
Yeah, I could use different systems. I'm making my own system which is far less combat centered. I can deal with the combat, but what I don't want to deal with are my players, honestly.
I've has about three different groups so far in my DMing time. All of them had the same thing in common: they loved killing things. It wasn't just, "let kill the monsters and take the loot." It really became killing just to kill things.
Maybe I'm just a little crazy. I've considered this many times. And i know the game isn't real, but I still don't like having the things that I create be brutally murdered just because, even if they are imaginary, and i do make the NPC's of my world...and all the other stuff.
One time, it was an NPC i had a story for. He had a wife and a daughter, who was key to the story i had in mind. Players go in and I, speaking as the innkeeper, say something that pisses off the player. So he cuts his head off, mounts it on a stick and parades around town scaring everyone off. The rest of the player thought it was funny. I was very sad. I rather liked that innkeeper...
OK. Simple solution to that. What was the town watch doing? Rough frontier town, well liked inkeeper. Town watch supported by the rest of the town. Adventurers don't stand a chance against a 20+ crossbow volley. Murderous PC killed while resisting arrest (I don't care if he was on his knees with his hands behind his head and begging to surrender before he took a crossbow bolt through the back of the skull from point blank range. Everyone will swear he was killed resisting arrest after he paraded round the town with the head on a stick.) Other PCs arrested, beaten, and sentenced to hard labour if they have the sense to surrender. After all, these are dangerous lunatics who hang round with someone who casually kills beloved inkeepers (or even Thenardier type inkeepers).
Next adventure for new PCs: chase down a certain bunch of wanted maniacs who have their likenesses posted to every town. Yes, the surviving PCs from the last game who have now escaped. Or keep playing with the PCs having to run and hide to stay alive. Every time they try a new village in a hundred miles, there's a poster up for them - Wanted, Dead or Alive. Danger, do not approach. Actions have consequences. And just because the PCs are strong doesn't mean they can deal with everyone else at once.
For more general advice see S'mon's posts above. Also try playing as well as DMing, and with a new group. (I'd refuse to play with a group that casually murdered like that - but wouldn't use D&D rules if I wanted a pacifist game).