What are the core features that must not change?

[Sifer2]

I am just saying I hate when in some games headshots do so much more damage than body shots that it overwrites all the normal weapon balance an the game becomes about just aiming for the head. Even though its unrealistic I think some games have it right when they restrict headshots to only certain sniper type weapons. An even then you still tend to get the "no scope" type BS where the guy is good enough to one shot people in melee range with it.

It also puts a lot more power into the hands of a hacker with an aim bot. Just like how making damage "realistic" in say COD makes wallhacks so gamebreaking.