Even if you do get bit, that victim usually has to die immediately in order for them to turn instantly, and when we do get to see that happen in a zombie film, it usually involves the zombie-to-be being ripped apart limb from gory limb by a horde of shambling undead. Otherwise if they escape with just a small bite, it takes hours or days of dramatic agony for them to become a monster.
So, realistically, that first day should be rough going for a zombie plague. Sure, humanity's not ready for you, but once we do see you coming, we've got the advantages of speed, firepower, and brains. Brains...mmm. Seriously, any city big enough to have a SWAT team should have the whole zombie thing under control on day one.
Yet despite those obvious truths, within no more than one in-character hour of the first zombie sighting, most films have the undead outnumber the living by a factor of 100 or more to 1. Sometimes, that's hard to swallow (unlike all those tasty brains, they go down easy). Unless absolutely no one at the police department has ever heard of a zombie before. But I'm interested in gaming on planet earth, usually in the post-Romero world where everyone knows that a pale dead-looking thing with blood pouring from it's mouth probably isn't friendly, long before it ever shambles into biting range.
Now, if you've got fast-moving zombies with rapid-onset zombie infections you might logically be able to go from patient zero to full-blown zombie apocalypse in a day or two. But even 28 days later, the movie that started the whole "fast zombie" revolution, realized that the apocalypse doesn't happen over night, it takes 28 days or so to get to the stage where most zombie films start.
Problem is, fast zombies with instant-conversion is really hard for table-top gaming, and this is after all a tabletop gaming blog. Players just generally don't care too much for an endless stream of "save or die" effects that would be required for a "1 drop of blood on your face and you go zombie" scenario. How do you get attached to a character who's that expendable?
So for my recently started zombie RPG, I turned a critical eye towards how I could make a slow-zombie apocalypse happen on a time-frame that was still interesting to play out. I didn't want to jump ahead four weeks past the end of the world, I wanted to game in the last days of mankind. Nor did I want my players to have to invest hours in a character creation process that might have to be repeated every three combat rounds.
Here's a few things that I figure any slow-zombie virus needs to get it's self up to the world-threatening stage before the CDC and US Army can shut it down.
- Densely Populated Epicenter: There needed to be some event at which a large group of people were gathered, and all exposed. There can't be one Patient Zero who personally bites every other zombie, there has to be a Ground Zero mechanism for a large group to be exposed all at once. Could be contaminated food or air, could be a deliberate act of bioterrorism, but it probably can't be one dead guy and his dentures.
- Delayed Conversion Allows For Dispersion: All those people at Ground Zero need to head home, or at least flee at human speeds. They need at least a few hours to disperse before they convert to undead status. That first wave have to spread out, and not even realize they're a danger to themselves or others. Ideally, the early infected need to be able to travel by plane and land in other cities before they know they're sick.
- Compromised Police Response: I'm sure we've all read tragic news reports that suggest that Police under pressure tend to get trigger-happy even when there's nothing about the suspect any more threatening than the color of their skin. Now put those same cops responding to the hordes of shambling dead. Yeah, it's a 6-gun massacre writ large and gory. So if the slow zombie apocalypse wants to have a chance in the big city, something else has to distract the police, or at least complicate things for them. Such as...
- Sympathetic zombies or carriers: The zombies can't be immediately distinguishable from humans. They can look sick, they can look hurt, but they can't look like flesh-eating monsters in the first hours of the outbreak. When the healthy see the infected, their response shouldn't be "shoot it!", it should be "OMG are you okay?!" A zombie plague that makes you want to bandage or medicate the early-stage zombies, and doesn't provoke the knee-jerk reaction of heading for the hills with gun in hand, has a much better chance of catching the most flies. After you've hit critical mass, you can have the zombies enter a bloodthirstier stage, but in those fragile opening hours there probably needs to be some doubt and moral ambiguity.
- Reason not to Nuke: Dropping in a daisy cutter, tac nuke, or the like is of course a cold and calculating solution to the zombie outbreak scenario. So the zombie plague has to be damn subtle, or leave some hope for a cure. Or else it needs to strike places too valuable to nuke, and too many of them. There's a number of possible solutions to this conundrum... or the GM can just let the PCs know the nuclear option is inevitable and suggest they go hide on the other side of that mountain. You've got options.
I started my game with the President being in town, and things getting ugly at the big protest/counter-protest/counter-counter-protest rally near his speech. 8 hours later, all those protesters, and the cops they wrestled with, start turning. They aren't monstrous yet, their brains are clouded, they've got fevers, and they're scratching at pus-filled rashes. In the meantime, there's news of some other(?) disease outbreak in another major city far away. Just enough confusion and uncertainty to let things get out of hand.
My original plan was to start with sympathetic zombies, and only show the first bloodthirsty one as the final image of the first session. It seemed like a natural cliff-hanger. However, my early sympathetic zombies were _really_ successful. There was a point where I was going to have to bridge the gap from disease victims to murderous zombies, or else the rest of the party was going to nursemaid themselves into terminal infection. Despite springing the predatory undead ahead of schedule, we still ended the session with one PC covered in zombie blood and driving a car full of infected to the church full of survivors. This does not bode well for that PC.
Oh well, at least there'll be no nuclear option until the motorcade makes it back to Air Force One.