I want to make it clear that this [i]is[/i] a medieval/fantasy concept. I put that in the tags but feel my post did not adequately reflect this. 

[@QT] 
1. What do you mean by "type"? They're of the more magical variety, and I plan to have several different variations - two of which being your zombies and your skeletons. Their movement speed depends on what they are, so your zombies are really only going to reach maybe a fast walk. Skeletons, on the other hand, will be [i]much[/i] quicker - like scary fast. Evolution is a fun idea. Unfortunately I'm really only familiar with World War Z, but from what I've seen from Resident Evil 7 it's probably closer to what I had in mind.
EDIT: Actually, I forgot Hunt: Showdown is pretty close.

2. Most survivors are indeed taking refuge in walled cities, and there are several of them. Efforts have been made for safer paths, but ultimately the safest method of travel is either by boat or in armed caravans.

3. Sadly nothing that isn't too typical. I'm still more focused on the world at the moment, trying to make it cool.

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[@Dumb1And1Lazy] Timeframe is roughly the medieval era, but the technology level will probably be slightly increased to maybe the renaissance (or it's dark and twisted cousin that never was). It's lower fantasy, magic for humans will be scarce and of religious value. At the same time, with the way I'm going with the introduction I'm willing to grant some extra leeway to the player characters. 

No definitive plot points yet, but there are organizations - both religiously driven and not - trying to ensure the safety of the surviving cities. I'm still mulling over how sandbox-y I should make this.

EDIT: [i]Also nice avatar[/i]