In the two days I've scrolled through graalians I haven't seen anything like this. I'm assuming that it has been brought up though because there's bound to be some other realists out there than just me. Here's my take on the issue.
I'm going to lay this simple. I believe that in some servers it is legal. And on others it is not. But on all of them, the government endorses it.
What are bases? A place to get hours? EZPZ Pks? I'm from zone and we have designated PK arenas. I think we have 5. All of them are always empty. Instead I see PKers at the SkyBase. I can tell you right now that if Zone was real, the skybase would be illegal.
Think about boxing for a moment. You can box and honestly kill people during a fight and not go to jail(trust me, it's happened more than once). You take the same two boxers and put them in a nondesignated area, and it is illegal. Zone has PK Arenas. Think about the Purge now. That's legal because the government is giving you the right to kill. But by giving you the right to kill there, can you kill throughout the whole world? No. Hence safe areas.
I conclude that on Zone, it is only legal to PK in pk arenas and anywhere else is pushing it.
On classic my theory is a little bit different. I don't think it's legal to pk at all on classic. Why? Classic has the most sound structure in terms of fictional government. There's an actual class structure and there's a government. If you're telling me that the classic government lets people just kill one another, the guy who has that one huge wine pit would be dead since he's got stacks on stacks of money. Now in basing, the rules are expanded and you can harm, but not kill. That's why unlike some other servers, the respawns are much farther away from the flag of the base. That's their way of basically saying you suck and you shouldn't try away. That's why they give swords and bows, not guns.
I conclude that on classic, all player kills are legal.
On era it's illegal. Gangs. They wouldn't have police if it wasn't. Basing on era is literally just turf wars which is always illegal.
Era PK is illegal.
Old west has no structure. Is it legal? No. Is it illegal? No. If anyone know who buffalo bill is then yea it's like that. If you're weak on power and kill someone, its illegal. If you're basically running the town and the sheriffs are afraid of you, who killed what now?
Okay I'm now going to contemplate about how my life went so wrong that I spent ten minutes writing this.
***Props to Sir since I had the idea to do this based on his signature or nickname, one of the two.