Chapter 4 - Religion

Civilization IV adds religion to its already deep and complex gameplay. Although it’s certainly possible to play entire games of Civilization IV without utilizing religions, the benefits of founding, spreading, and practicing one or more of the seven available religions certainly encourages you to experiment with the new feature.

Religions are founded through technology research. The first to research certain technologies founds the religion and can then spread it to other cities and civilizations and begin to construct religions temples for happiness and culture and eventually special structures to generate income.

The chart below reveals the technologies required to found specific religions. Expect computer-controlled civilizations to found a religion or two; certainly one civilization will go for Buddhism, which is the easiest to found on the technology tree.

A Uniter or a Divider

Having multiple religions provides the opportunity to change your state religion to appease a rival or to gain more benefit from a particular civic.

Religion is one of the largest factors in diplomacy. Sharing a religion with another civilization provides a diplomacy bonus. You will have a good relationship and be able to conduct various trades and alliances much easier because of the common bond shared; take note of the positive benefit from the shared religion while highlighting the other civilization’s name and revealing the pluses and minuses that are factoring into your good or bad relationship.

And it’s religious differences that can play a huge role in poor trade relations and even war. It’s a huge diplomacy negative to have a "heathen" religion according to your rival civilization. Couple it with a few other factors (you refused to give us tribute!) and troops could be filing into your borders and straight for your cities. Religions can unite you with other civilizations or divide you.

One of the pluses (and there are several as these tips will discuss) to having multiple religions (and being a spiritual leader) is to switch state religions to match other civilizations to get on better terms, even if it’s only temporary (perhaps to form a short alliance or to negotiate a valued trade). Perhaps a neighbor civilization has a different state religion. Perhaps that same neighbor civilization is a military powerhouse. It would likely be in your best interest to switch your state religion to match so you can help maintain the peace! Once again that shared religion bonus is a big factor in keeping other leader’s in your good graces.

Spreading the Faith

Because shared religion is such an important factor in successful diplomacy, it’s wise to spread your state religion to other civilizations. You do so by sending a missionary (or multiple missionaries) into a rival civilization’s city and spread the faith. You can found and spread multiple religions. You can select one as your "state" religion. If another civilization adopts your founded state religion, you can gain sight on their city.

The key to spreading the faith is obtaining open borders agreements with other civilizations. Now you can freely explore inside their borders and send missionaries to their cities to spread your religions. This is important early on not only to maintain good diplomacy with neighbors but to lay the groundwork for a stronger civilization in the late game when you have turned religion into quite a profit.

If you plan to focus on religion, construct temples and subsequent religious structures (monasteries, cathedrals, etc) for their various bonuses to happiness, research, and culture. You can also use priest specialists and spawn Great Prophets. You can build a shrine in cities religions were founded ("Holy Cities"). The shrine supplies benefits of other religious structures but also generates commerce for each city that bears the shrine’s religion. This can be very, very profitable if you’ve spread your religion faithfully! Found multiple religions and build multiple shrines. Spread the faiths around to foreign cities and start earning.

Religion can impact your technology decisions. For instance, perhaps you want to add Free Religion to help boost happiness. You’ll need Liberalism.

Founding a religion early will help the spread of the faith. If you wait and found a religion that requires a later technology (such as Christianity) then other civilizations will already have founded their religions and spreading yours (and maintaining good diplomacy) will be more difficult. But founding an early religion also means devoting research time to those technologies and not to technologies that may help you gather resources or even rush to construct an army. Focusing your entire strategy on religion and its profits is viable but obviously can leave you vulnerable to other tactics, for instance a military rush. If you want to aim for early and multiple religions, choose a leader that already has the Mysticism technology researched. These leaders are: Asoka (Indian), Gandhi (Indian), Huayna Capac (Incan), Isabella (Spanish), Montezuma (Aztec), and Saladin (Arabian). Follow the tech tree through the religions and found them first!

Keep in mind that religions will need to be spread within your own empire as well. One city may found a religion but others in your empire may not adopt it or may even be influenced by a rival’s civilization’s religion. Use missionaries to spread the faith within your own borders. Spread your state religion to gain more from its benefits. Having multiple religions in each city isn’t a bad thing. You could use the Free Religion civic to help boost happiness throughout your civilization; it adds +1 happiness per religion for each city.