Originally posted by Pembroke
There was a discussion about having religion in the game in the Creation&Customization forum. It _is_ possible to implement it without offending anyone. What you have to do is to stay strictly generic with it. Religion can be a VERY touchy issue so that really is the only answer: strictly generic.
One possible implementation could be to refer to the religions as "the Roman religion", "the German religion", etc. Of course, if you yourself then mod these names to your liking in the editor then that's entirely your private business. OTOH a generic reference does have the advantage of not having any "semantic ballast" going with it so you can play it with an open mind. After all civ is pretty much an alternate history simulation.
But then the big question: What would religion mean in the context of the game rules?
It has to have meaningful game related effects. Otherwise there would be no point in adding religion in the first place.
Religion could act as a complement to the governments and culture and bring to the game a degree of social engineering. For example with a simple definition that "a religion" (in the game engine sense) is a combination of attributes and their values you can do quite much:
The German Religion at 4000 BC:
Domestic: 0
Trade: 0
War: 0
Culture: 0
Science: 0
Notice my choice of attributes: they correspond directly to the "advisor screens" of the game. Their names could be changed to more descriptive ones but I want to explicitly refer to these aspects in this example.
A ruler can't (really) determine the religion of his people. Religions emerge, form and evolve. (No disrespect meant; just a simple historical observation; add Divine Guidance if necessary). This ought to hold true in Civ, too. However, what the ruler can do is to lead his people. So after building lots of warriors and spearmen (War), maintaining social peace with troops (Domestic) and not building many temples, libraries or courthouses (Culture) and pretty much ignoring scientific research (Science) but building lots of roads, marketplaces and trade with neighbors (Trade) there has emerged for the Clever German Folk a religion:
The German Religion at 1 AD:
Domestic: +1
Trade: +2
War: +2
Culture: -2
Science: -3
And now we have something to work with. These attributes can have direct effects in the game related to their meaning. As there are both bonuses and penalties it's always a trade off which keeps the game interesting. Also, as the player does not have a direct control over the religion of his people it works as a "cause and effect" feedback to his actions.
And what about the religions of other nations?
Naturally the more the religions are similar the better their relations ought to be, although not necessarily peaceful. An attitude modifier based on the religion difference ought to be an easy one. Also, going to war against a civ with a similar religion might invoke discontent in your people: "Stop the aggression against our brothers in faith!"
Religions ought to have far-reaching influence, too. This could mean that two nations having trade deals and/or sharing a border influence each other's religions bringing them closer together over time. Perhaps so that the culturally more powerful civ has an advantage in this. In cultural city flips the distance of religions might give a modifier, too.