Most cod but specifically the Barrett from MW3. A rifle that powerful can rip someone's limbs off without directly hitting them but it take two shots in regular(core) but getting knifed is an insta kill. Another cod thing is the quick scoping. You have to be laying down with a proper grip on a rifle to aim/shoot properly without injuring yourself but Ingame you can sprint and maneuver as if it's a pistol and quick scope while effectively killing them. Also the .44 magnum would probably kill your hands after being rapidly fired in a span of a few seconds yet your character simply reloads for the next kill. Now I know the game wouldn't be as fun if these things were implemented but realistically speaking none of these are possible.