dc heroes & Killing

DC Heroes takes killing very seriously. A Player has to deliberately enter "killing combat" to kill or be killed, and if they do, "this Player loses any Hero Point awards he might have gained." Yeah, no experience for that play session at all, that's the penalty. Moreover, the rules add this:

"NOTE: Players who consistently forfeit [Hero Points because they entered into killing combat] may not be asked by the GM to participate in any further adventures."

Once or twice because the fiction demands it? Go ahead and make that call, but you get no Hero Points. Do it regularly? You are probably not welcome here.

(Marvel Super Heroes is similarly constructed. There a character loses all her Karma points if she "kills someone or takes no action to prevent the death of an innocent person that [s]he could have saved." But the Karma system is much more interesting and complicated, with a whole list of things that add or subtract Karma. The game however never says you can't commit crimes or become a villain, only that you'll be punished with bad karma. DC Heroes goes much further in stating that the GM has every reason to boot your ass from the game.)