Since I run a Apocalyptic campaign recently, including base setting and improvement, maybe here are some ideas for you.
Initial base: instead of giving them a base, let them choose amongst a few options (three bases), with different pro and cons for each.
Example:
- a military bunker in a forest: easy to defend, but no land to grow food around, possible contamination with chemicals, high presence of zombie. May or may not have some spare supply, usually include generators and even water purifier (but are they running, are they contaminated ?)
- a farm converted by a sect retreat (like Waco tragedy), with a decent fence, farmable land. Not as sturdy as the military base, but more potential for autarcy. Far from the next city - gas consumption will be a limiting factor to organise raids to retrieve missing goods.
- a luxurious 6 story building in the middle of the city. Good security system - however some glass walls on the ground floor should be quickly replaced by sturdier materials. Proximity of the city and relative ease of access to retrieve goods. No cultivable lands, however a glasshouse and hydroponic farm on the rooftop could be installed since there is already a swimming pool.
Depending if you consider having magic or not, an aura or some source of power can also be additional advantages.
Your campaign will go through three phases (or maybe even four depending when you start).
Phase 0: during the apocalypse - the PCs have to survive the raise of the dead, whatever triggers the Zombocalypse. Very likely, they are limited with what they have on themselves or in-house when it started. Survival is based on a daily (even hourly) basis. You might skipped this phase, or run it as an introduction scenario with disposable PCs (which may or may not be immuned - if they survive, they are
)
Phase 1: after the apocalypse. They are survivors. Now, survival is planned on a weekly basis. Pillaging for food, gas, ammo and locating a place to settle. It should become obvious than staying on the run is not sustainable: having to always move means you never have a strong shelter and you need to find gas on a weekly basis if not more, and if you have wounded people, it becomes even more a strain. Do they pick up some people that most of the time will be a responsability and a burden (more mouth to feed and to protect), but could from time to time provide some unnexpected help (having a unique skill; surgery, speaking a dead language, having some visions or other supernatural ability). Fresh food availability is decreasing rapidly as after a week or so it naturally spoils.
Phase 2: settlement. They have found the place they believe is suitable. They need to reinforce it and plan for the longer term: how to become self-sufficient for food - pillaging super market might only last so much. Fuel is not hit by peremption date, but securing it might requires taking more and more risks. This is where crafts and technological skills become more prevalent: how to install solar panel - impossible to make new one, but salvaging is very much an option, how to heal fractures, wounds and diseases, how to repair a water well and so on. Ammo can become scarces. Training with other, more primitive but easier to maintain weapon might be required.
Phase 3: expanding. The daily life might not be bright, but at least food is sufficient to prevent starvation and the protection of the settlement from zombie hordes has been proven. The PCs are not anymore on survival mode, they can start thinking on the future: how to reclaim more territory, finding out other survivor camps, what did cause the zombocalypse and can it be stopped, is there a mystical ritual to banish the invasion from the dark dimension ?
As zombies varieties, there is an excellent book called "Zombies of the world"
.
For my campaign, I had those various types (all undeads):
- Basic zombie: stupid, slow, hungry, but relentless, more or less blind but gifted with the ability to sense living people within a certain radius. Easy to avoid alone, easy to outrun, but PCs needs to sleep, they don't. Adjust their ability to track to your taste/need;
- the ghoul: faster, more agile than a human, cunning (but not intelligent), rare. In group of 3 to 10. Have talons and can climb walls, tears tile from a roof. More dangerous than zombie and useful to test a security perimeter. Cannot carry mission, only driven by hunger;
- the bloated corpse: a huge (3 to 5 meters - 9 to 15 feet), obese, monstruosity moving as fast as a human (hence slow for its size), able to "discharge" zombies from its belly. Cunning, but still not intelligent. Able to take controls of zombie around it - range of the ability up to you to decide (sight, 100m, 1 km, or more);
- the hunter: intelligent, as agile as a human, rarer than ghoul, able to raise dead animals (especially dogs/wolf) that it uses to track people. Act usually alone. Can set trap. Good for harassing a small group of PCs.
- the mist bearer. Similar in appeareance to a regular zombie, but intelligent and more agile, rare. Surrounded by a green, heavy mist which raise dead bodies. Can control every type of zombie. Motivation to be decide by the DM - or simply driven by hunger;
- the delicious corpse. Look very much like a living human, including a warm body (although no pulse). Exudes strong pheromons at will, which makes people form both sex fall for it. They are not contagious except when exchanging bodily fluids. Intelligent. Rare. Used by power behind the scene to enter and weaken stronghold. Their victims don't turn immediately into zombie, the process takes several days, during which they behave like human, but follow order from the delicious corpse. After 7 to 10 days, they rot and becomes mindless zombies.
The three first types can easily be seen as variant of the basic zombie type and can go with more or less any setting. The three next one are more suitable if there is a power behind the scene to explain their existence - and magical background is almost a requirement to justify their existence.
That's it for now.