BTW, Ylorea, in every system I play, Flanking allows sneak attack, but that is beside the point. I use a strange hybrid system. I hand the players a large tactical scale battlemat (Whatever the largest Crystal Caste is, I don't remember), and then describe it to them. That way we have a tactical map, so when they pace off rooms, I give them the dimensions, and then if they mess up, they are up a certain creek, sans paddle. It works well, allowing dungeons to be nice and tactical, but no maps elsewhere, unless they specifically draw one and survey, as Ylorea mentioned.
EDIT: And my players have gotten very good at playing by description, so we don't actually need the map anymore, but we are initiating a newbie, and she needs to be able to see the map. I find that for experienced players, it works just as well either way.