There are lots of games where combat is not even an option, like Life is Strange, Before your eyes (do play this one with a camera and a box of tissues nearby), or Firewatch. But games where you’re expected to fight but can find ways around it the first example that comes to mind is Metal Gear Solid 3, you can beat that game without killing anyone, there’s even an achievement for that and one of the bosses will be particularly easy if you go this route.