You could say that about a lot of games. It is a common approach. Every compression scheme you can imagine has been used and more, from simply shipping the whol

You could say that about a lot of games. It is a common approach. Every compression scheme you can imagine has been used and more, from simply shipping the whole thing after all to procedural generation and everything in between. I seem to recall Oblivion was mostly procedural on the overworld but then people would come in and edit the maps afterwards for various things.