This mod from the Fall from Heaven Team is a dark fantasy mod. Features include magic, an experience system, and changes to upgrading, religion, heroes and technology.
Author: Fall from Heaven Team
Fall from Heaven II is a dark fantasy mod for Civilization IV. The Age of Ice has ended, what is left of the once great empires of man have formed into small tribes, ready to rebuild and retake that which was lost. But the world is not empty. Hordes of barbarians await these new civilizations. Wild animals stalk hapless scouts and reckless emissaries. Giant spiders lie in patient wait in the jungles and the forests waiting for their prey to take that last, fatal, step.
There is great evil, but also selfless good. There are those who strive to remain neutral in the coming conflict as opposed ideologies break the world asunder once again. The first goal, is survival. The second goal is power, for good or ill. Will you pursue power through strength of arms or arcane studies, through piety or blasphemy? Choose carefully. On each path you will allies, and bitter foes, and the deeper you delve into the secrets of combat, or sorcery, or the divine, the harder it will be to turn back.
Here is a brief list of some of the new features in Fall from Heaven:
Magic! - Spellcasting units can take promotions in the different spheres of magic, granting them access to new spells and abilities. There are three sorts of casters, those that know Sorcery, those that practice Summoing and Divine casters. A unit has access to spells depending on what sort of caster it is and the spell spheres it chooses which of 14 spheres it wants to learn when it levels up (Fire, Entropy, Nature, Spirit, etc). Casters gain experience slowly automatically, so there is no need to risk them in combat as they pursue their studies in the mystical arts.
Experience - Veteran units are now more valuable. The base promotions have been essentially doubled, making the difference between experinced units and greenhorns especially noticeable. Also, new anti-racial promotions have been added, become the scourge of the elves, if it suits your fancy.
Upgrading - In order to upgrade the the strongest units a unit must first prove itself worthy. Do you want to be an Immortal? Unable to die, and thus able to fight for all eternity? Then you have to be at least a Lv. 6 Maceman.
Religions - Not all religions are created equal, and some of them effect the alignment of your civilizations. If you choose to follow the vile practices of the Ashen Veil, your civilization will descend into the depths of Evil. You will of course be rewarded with immense arcane power, knowledge and the aid of Demons. On the other hand, if you follow the Runes of Kilmorph, you will be able to obtain the aid of the reclusive dwarves and share in their love of gold and gems.
Heroes - In times of darkness and strife, heroes will rise to lead their civilizations to victory. Heroes are world units, that can only be built once. If they die, they cannot be rebuilt. Each civilization has at least one hero associated with it, as does each religion. Heroes gain experience each turn, meaning that in any given game, they will probably be your most powerful unit by far. They are capable of taking lightly defended cities by themselves, but they're only a short dogpile away from being dead, so protect them!
Technology - Specialization is the name of the game here, while you may be able to generalize into the first or second tier of techs, you're probably better off specializing in one of the various forms of combat or the arcane or the religious. Tech progression is noticable slower in FfH, giving you an opportunity to play with those new toys you just discovered. There are also religious specific techs, that cannot be researched unless you follow the appropriate state religion.