do i need a vent for my new home basement plumbing rough-ins
if you mean a vent in the plumbing, then yes.  wet or dry, the plumbing must be vented.  if you mean an air exchange vent to pull moist or smelly air out of the room, then it may or may not be code in your area, but do yourself a favour and just put one in.  its always a good idea.