@Raylahthanks for interest. :) It will not be a typical NRP. Basically each “nation” starts out as a small group of people with a limited amount of resources and land. Over time they will be able to recruit more survivors and acquire more land as they scout more areas (dice rolls will be performed).
As the groups expand, there will be more need for organization and policies. Each turn will possibly span a day or a week, and the leader gets to send out people to scout new land, clear nearby zombies, scavange food and resources, build barricade, guard their own territory against zombies and possible human invasions, research for cure, etc.
Possible important indicators will be survivor count, happiness level (sad population will be more inclined to leave the group or deny helping), food supplies, medical supplies, transport and oil supplies, weapon and ammunitions, environment zombie threat level, group technology level etc.