> Survivors are going to have a hard time out for them.

That's the idea, and why I will be interested in seeing what tactics players come up with for dealing with the problem. Would be pretty worrying if some old gaffer drops dead in a back alley, wakes up, and alerts its undead buddies in a fifty mile radius, wouldn't it? Worse, what would happen if you engaged a horde of undead? How would you stop them? Ditches filled with pitch? A gauntlet of stakes and explosives? Would a small trickle of them attract an even larger stream? 

This RP will not be a simple "k I'm taking over this plot of land now", it'll be "okay I want this land, this is how I've done it." 

Players will then be like, "bitch that ain't happenin'" or, "bitch, that's some cool shit." 

Of course, another interesting aspect will be what shape the societies have taken. Facing potential danger from within, and from without, what methods have they established to deal with the random old gaffer? Do they monitor everyone at all times, with an insane and ingenius secret police? Is everyone assigned a "watch buddy" at all times? Do soldiers patrol the streets in droves to put down any resurgent dead? How are the dead disposed of? Good old fashioned fire? Or improvised explosive burial grounds? 

Should be fun.