One concern that has been brought up by the few people I have discussed this game idea with is: How do you replenish supplies in the world?
This is a very complex issue, that after much though has a very very simple solution, and that is: You don’t. Not directly anyway.
To be honest, one of the problems I have with many games is the endless respawn of stuff. Now, I did say this would be a world of endless zombies, but all my zombie spawns would be “at the edge of the world”. Anywhere a “populated” area meets an “unpopulated” area is a potential spawn point for zombies because they are wandering in from other areas. But monsters and items fading in to view appearing out of thin air while the player watches… not in my game, its immersion breaking.
As for food and other supplies that players go after, in their area they will eventually scavenge it clean, at which point they’ll need to either a) start with the farming, b) widen their scavenging routes, or c) move somewhere else. If they choose a, then there is no need to handle any replenishment of supplies, they will find make them themselves. If they choose b or c… well, you don’t want the world to eventually be totally picked clean, so what you do is, when an area remains “unpopulated” for a length of time, you reset it, and everything goes back to like it was on launch day.
By design, the game will take care of all potential issues except for player memory. Players who used to live in the area that haven’t logged in will have eventually starved to death (as mentioned before, the game is going to have a level of persistance not used in very many games, when you are offline your character is still living), which is one of the factors in deciding to reset the area. However, nothing could be coded to prevent a player from remembering that they used to live in that area but had moved out. They’ll remember clearing the mall and eating all the food, perhaps even burning it to the ground, but suddenly upon area reset the mall will be back and stocked (with supplies and zombies).
The only real issue facing the game is making sure there is enough world to support the players, but that’s an issue that would have to be planned for but addressed only if the game exceeds expectations.