Civ IV: History ReWritten is the number one mod in my opinion for Civ IV.
The creator Xyth has created a
religion system, similar to the civics system, where you use reformations to shape your faith and what bonuses come with it.
There is also a great
civil war system. This solves the major issue with all Civ games, where you reach "critical mass" and basically you know there is no way you will lose as your civilization just generates production and gold exponentially.
In HR [History Rewritten] as you grow and gain more cities, just like throughout history, your civ becomes more unstable and expensive. New cultures and religions leads to growing
dissent (a new system, that works alongside happiness/unhappiness, and is effected by culture and your espionage). As dissent increases you begin to have a risk of civil war.
I was playing on a real earth map with 12 civs, in the middle ages revolutions began to occur across the globe. The Celtic Civ split, and England was created on the British Isles as it should be, with celtic groups scattered from Iceland to norther Europe.
Xyth also has worked in
real world wonders to his maps, which give unique bonuses to certain squares (great barrier reef, Mt. Everest, Kilimanjaro ect.)
Every civ has two
unique units, a unique building, and a unique national wonder.
He has also greatly
improved the technology tree, adding new technologies, and creating a far more logical path to development.
Most importantly, for windows users the most recent iteration of the mod incorporates
K-Mod!
This mod is very much alive, and is constantly being improved every few months by Xyth. He is always looks for testers and folks to help out with Civilopedia entries for the
135+ civilizations and leaders he has added to Civ IV. So check it out!
http://forums.civfanatics.com/showthread.php?t=560143
