Returning tech: Nothing electrical yet. EMP made sure of that. Guns still work, but cars won't. 
'Magic': It can be anything that isn't OP, and is of any of the twelve elements (which I will post in the actual thread)
the creatures themselves can't be OP, and can't resemble humans (there are already two exceptions, and even those can only be considered borderline), this basically means no 'vampire' species, 'half-demon' species, or 'anime chick' species allowed.