If an innocent does 10 or more damage to you, you should be able to kill them and lose no karma.
Guy 1 is shooting at at someone, or throws a grenade, etc.
Guy 2 intentionally jumps into the line of fire and gets hit.
Guy 2 kills Guy 1 without punishment.
Alternatively, Guy 2 shoots you in the leg with a pistol, doing something like 5 damage. He knows this is not enough to trigger your rule. Guy 1 kills him and still gets punished.
Broken rule, rewards trolls.
I'm not going to get into a long winded discussion on this topic. Every system and rule you can think of
will be exploitable. It's not that bad for the karma system as-is, and any change is going to make it worse. "Any change"? Yes, because I've already thought of anything you might suggest when I designed the karma system. The mechanics are based on
a lot of discussion and experimentation. They work decently, and that's as good as it's going to get.
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