Retaliate then, but don't try and Pk anyone. RP it right. If someone is Powergaming report it to the current admin in-game. Only SA's have the right to declare someone PK'd. But really do anything unrealistic won't work. If someone has a gun to your face, and you pull a shotgun, no sweat, and kill them is way not cool. First by the time you got your shotgun out, they would have killed you. Think that your character could be PK'd for every little thing and you will start to value them more. Knowing you can't die, and doing irrational things is just dumb. RP it right and more or less realistic.