Rhye's and Fall of Civilization is a modpack for Civilization IV that attempts to make your single player game an “Earth simulator".
It can be considered both a mod and a dynamic scenario: Rhye's and Fall of Civilization revolves around the re-enacting history on Earth, guiding your game in through an alternative, but still realistic history, unique every game you play.
This mod doesn't feature loads of new units, civilization and other "stuff": it's focused on new concepts