It's just an idea as of now; I don't even have any concrete ideas on the rules or anything. What I do have is some poster board and some bigass sheets of 1x1 inch graph paper and a lot of free time. I've also got plenty of dice (about 25 D6s). I want this to be a community project thing where everyone can feel free to contribute ideas, artwork, or anything else that's helpful you might think of. Vaguely what I have imagined is a competitive game consisting of at least two players. There should be at least one player controlling the zombies and at least one controlling the survivors. I imagine that the survivors will be largely avoiding combat (preferring to run and use barricades), while the zombies will be all about mindless destruction. That's really all I've got in my head at the moment, so feel free to post suggestions.
Rules as of Now:
-The Horde
When a zombie is within one square of another, both zombies get another action in their turn. This bonus stacks. For example: a zombie on his own has one action, which he can use to move 1 tile, take 1 hitpoint off of a barricade, attack a survivor, etc. If another zombie enters a square adjacent to zombie A, then they each have 2 actions. If zombie C moves up adjacent to B, but not A then C and B would have 3 moves, while A would only get 2 moves. To get their action bonus, zombies must stay adjacent to each other for the whole turn. If A has 2 moves, but his first move transports him one tile away from B so they are no longer adjacent, zombie A's turn would be finish immediately. Zombies all take their turn together at once to allow for hordes moving together. I may add something where Survivors get a morale bonus or something for being together too.
-The Hunger System
Every time a survivor moves 1 square, he or she must draw a hunger card. As you collect more hunger cards they will have more sever effects (for example, if you get 5 you have a smaller inventory or something). The most severe of these effects will be either death or immobilization. You can discard hunger cards by using food cards that you can collect some way (I haven't decided how yet) during play. Different food items will allow you to discard different amounts of hunger cards. Zombies have 30 (this number is subject to extreme change) turns from the start of the game before they starve to death. By killing a survivor, a zombie can extend her own life by 15 (again subject to change) turns. A zombie can eat another zombie (with the other zombie's permission) to gain the consumed zombie's remaining time (for example if zombie A and zombie B both have 7 turns left until they stave, A can eat B and have 14 turns until she starves).
-Items
On the map are various containers such as cars, dressers, etc. These containers can only be looted once by survivors, but there are tons of them around the map. Zombies may destroy containers taking up one turn, making the container unable to be looted by survivors. They take one turn to loot and on looting them the survivors must draw a hunger card. Whenever you loot a container you may draw from the "items" deck. I will have a full list of items later (feel free to suggest some!) but I imagine they will be things like food, energy drinks, weapons, and barricading materials.
-Death
When a survivor is bitten by a zombie, he or she has 5 turns before he turns into one. I'm thinking that maybe there will be an extremely rare "zombie cure" item that a survivor may take in order to stop the infection. If a survivor is bitten twice by a zombie, he immediately dies and becomes a zombie. When a zombie dies, he will rise again in 3 turns wherever his body is. Dead bodies may be dragged by survivors at the cost of an additional food card per square (one for the movement plus one for the body).
-Winning
Zombies win when they have converted all of the survivors. Survivors win when all of the zombies have starved to death.
Thanks to:
Everyone who posted suggestions