Religion...
that's the big question !!
Nobody rised this issue but. I can probably assume that we can agree that religions are loosing their influence on the people and civilisations since our world became a global village.
there's more and more atheists, more and more acceptance for mixed marriages, people dont care so much about church i.e. comparing to medieval times.
I agree that State Atheism should be a civic, but I disagree that religion has become irrelevant in the modern world. Bush's form of evangelical Christianity; Islam; Judaism; these religions and the differences between them are still fueling wars, as we speak.
One aspect of religion we can see in the modern era which doesn't exist in the game is a sort of ecumenical affinity, similar to diplomatic relations between empires: sometimes religions get along better with certain other religions, than with yet other religions. Christianity and Judaism currently seem to be teamed up against Islam, in the global struggle for humanity's soul; yet if this were a Civ4 world, they'd all hate each other in equal proportions.
What might be a good new feature to add would be a religious relations function, where religions either get postive or negative toward one another based on the same factors as between the civs as a whole:
1) Years of peace between the shrine-owners of religion A and religion B.
2) Common cause in a war.
3) Trading with the enemy of religion A.
...etc.
In this way, sometimes there would be a large diplomatic hit to being a different religion than an AI, and sometimes not.
This also reminds me of a diplomacy issue: why is it impossible to know what level of relations each AI has with each of the others? "Furious, Annoyed, Cautious, Pleased, Friendly" should be visible not just between the AI and you, but between the AIs and each-other. At the very least make it available upon the establishment of an embassy or spying mission, which (and I hate beating the Civ2-was-better drum all the time but it's TRUE) was available in Civ2 (I think it was upon Writing you could build a "diplomat" and establish an embassy to reveal inter-civ relations).
Nowadays religions definitely does not have so much cultural and espionage impact as it has been set up in civilization 4. I would strongly recommend to decrease religious benefits while civilization is more and more advanced. Probably an internet could be a kind of turning point. The ability to give happiness, culture and information aboult rivals' cities should decrease during times.
OR... in the modern era let Atheism gain an equal if not slightly higher footing than religion in terms of ability to generate happiness. The problem with having Atheism as a "religion" is that Atheism has no concept of a shrine or a holy city. Even if it has "missionaries" of a sort (Atheist philosophers), and libraries and universities can act as its "temples", the business of shrines nags at me and makes me want to avoid it as an alternative religion. However, as a religious *civic*, it makes perfect sense. And maybe this can be captured by Free Religion getting slightly more powerful in the modern era (maybe the 10% beakers benefit goes to 15% after Industrialism), and adding a State Atheism civic to represent such states as the former USSR and how they approached religion: they didn't, after all, have "FREE" religion, now...
It is also a chcracteristic of christian church which is institutionally and politically organized. I would not say that bhuddism or taoism should give so strong espionage benefits as christian church. Each religion should give different benefits for sure, and differently changing during times. Probably buddism should give more happiness, christian more espionage benefits, islam
military and so on. Islam could keep the benefits till modern times, while christian should be decreased ealier.
That's a good idea. Unique religion-based bonus attributes of some sort. Maybe allow these bonuses with the building of the religion's shrine, such that, instead of just a WEALTH bonus, each shrine could have a unique bonus. Some ideas:
Buddhist Shrine = +25% culture in cities with Buddhism; +50% with Buddhist Temple; +100% with Academy
Hindu Shrine = +1 health in cities with Hinduism; +2 with Hindu Temple; +3 with Mandir
Jewish Shrine = +5% wealth in cities with Judaism; +15% wealth with Jewish Temple; +25% wealth with Synagogue
Taoist Shrine = +1 happy in cities with Taoism; +2 happies with Taoist Temple; +3 happies with Academy
Confucian Shrine = +5% beakers in cities with Confucianism; +15% beakers with Confucian Temple; +25% beakers with Academy
Christian Shrine = -25% war weariness in cities with Christianity; -50% WW with Christian Temple; NO WW with Christian Cathedral
Muslim Shrine = -25% unit maintenance cost for units built in cities with Islam; -50% unit maintenance with Muslim Temple; NO maintenance cost for units built in cities with Mosque
...something along those lines
Edit: obviously these benefits should only work if you *have* the city with the religion, and the shrine. If someone else has the Muslim shrine you don't get the effects in any cities you have with Islam, nor do they get the effect for having spread their religion to you.