I couldn't find any other reliable website where I could ask this question, even though it has no specific answer (which the rules suggest). But I have a strong feeling this is an easy one for experienced GMs.
I'm in a long term AFMBE campaign, and this is my very first game as a GM, ever. I've already done 2 sessions of about 3 hours, to give you an idea of my experience. I've played about 30 hours as a player.
Right now, to their knowledge, the world as ended, the human population is drastically reduced and zombies roam freely. I would like to start to let them know they are actually smart (some of them, not the 'grunts') and they are already organized.
It all started because of radiation and radiation is and should be an issue in dense areas.
The subject of interest
I'm trying to have a city that has a human side and a zombie side, pretty much like they did in World of Warcraft with the city of Shattrah.
That would be a very cool hub for quests, dialogues, and a general good source of "reasons and ideas" for me in the future. I would really like to have this, or something similar.
But I need a reason for it to have happened, a way to make it work because of radiation, and a reason for both sides to not attack each other relentlessly. And I don't want to say "it's like that, deal with it."
Practically, the city is shaped like an egg, north side is human, south side is Z. There is a very large road that crosses horizontally which is the frontier.
I'm thinking all the radiation would be only in the south side, and there would be a massive lead/concrete wall or something similar to help reduce the radiation.
The middle road could be some kind of "no mans land" where nobody attacks each other but everyone can interact and trade (quests, etc.). I think this is really cool, and it'll make them very curious of the zombie side. Which I could use later.
Now that area would be dangerous because of radiation, but there are practical ways to handle it (hazmat suits, not staying too long, etc.) That can be dealt with.
What I can't find is something smart and reasonable for this to happen in the first place, and a good reason for everyone to not attack.
I was thinking of some kind of "forcefield" (like UV lights) so zombies wouldn't attack, and zombies would have trading supplies that human needs or something. But that doesn't really work because my zombies are daylight friendly, and also this all feels... not real.
So anyway, I'm here for some seeds, if you could give me some ideas to make this work in a reasonable and realistic manner, that would be amazing :D
Sorry about the wall of text for such a simple question. I wanted to give as much information as possible to get the best answer possible.
Thank you very much for your time.