Religions

Civilization 4 has seven religions (Buddhism, Christianity, Confucianism, Hinduism, Islam, Judaism and Taoism) with identical effects; each is founded by the first civilization to discover its technology, in a Holy City that can later build the religion's shrine. Religions spread on their own and by missionaries, and a shared or rival State Religion shapes how the AI leaders treat you.

Civilization 4 has seven religions (Buddhism, Christianity, Confucianism, Hinduism, Islam, Judaism and Taoism), and all of them have exactly the same effects: the only difference is the technology that founds each one, and the first civilization to discover that technology founds the religion in one of its cities, its Holy City. Religions then spread along trade routes and through missionaries, give happiness and culture to the cities that hold your State Religion, pay gold through their shrines, and sway the AI leaders, who like a shared faith and resent a rival one. 2K calls Civilization 4 "the first entry to feature Religions that can spread across the map" on its official page.

Quick facts

Religions	7, all with identical effects
Founded by	The first civilization to discover the religion's tech
State Religion bonus	+1 happiness and +1 culture per city with it; +5 culture in its Holy City
Shrine income	1 gold per turn for every city in the world with the religion
Shrine built by	A Great Prophet, in the Holy City only
Cathedrals	One per three temples of that religion
Religion Advisor	F7
Religious civics	5: Paganism, Organized Religion, Theocracy, Pacifism, Free Religion
Added in Beyond the Sword	The Apostolic Palace

The seven religions

Religion	Founding tech	Tech cost	Cathedral	Shrine
Buddhism	Meditation	80	Buddhist Stupa	Mahabodhi
Hinduism	Polytheism	100	Hindu Mandir	Kashi Vishwanath
Judaism	Monotheism	120	Jewish Synagogue	Temple of Solomon
Confucianism	Code of Laws	350	Confucian Academy	Kong Miao
Christianity	Theology	500	Christian Cathedral	Church of the Nativity
Taoism	Philosophy	800	Taoist Pagoda	Dai Miao
Islam	Divine Right	1000	Islamic Mosque	Masjid al-Haram

Source: founding techs from the Civilization 4 manual, pp. 81-82; costs (version 1.00) from GameSpot's guide, Jan 18, 2006; cathedral and shrine names from the Warlords manual, charts pp. 129-138.

The order matters more than the religion. Because the effects are identical, the only real choice is which tech to chase, and the cheaper ones go first: GameSpot's guide expected the AI to found "a religion or two" and called Buddhism "the easiest to found on the technology tree" (GameSpot, Jan 18, 2006). It named the base-game leaders who start with Mysticism, and so reach the early religious techs fastest: Asoka, Gandhi, Huayna Capac, Isabella, Montezuma and Saladin. The Technologies page shows where each founding tech sits on the tree.

Why every religion is the same

Firaxis made the religions equal on purpose. The manual (p. 77) says "All religions in the game have the same effects, the only difference being their technological requirements", that testing found seven "the optimal number for gameplay", and that the seven were chosen as those "most familiar to our audience", adding: "We're game designers, not theologians." Senior producer Barry Caudill's developer blog post of Sep 15, 2005 tells the same story: seven was "a number that seems to come up quite often when designing versions of Civilization".

Holy Cities and how religions spread

The first civilization to discover a religion's tech founds it in one of its cities, which becomes that religion's Holy City (manual, p. 78). Owning a Holy City lets you see into every city in the world that has its religion, and everything those cities can see (p. 80), and it is the only place the religion's shrine can be built.

Religions spread on their own. They travel from Holy Cities to the cities they touch, faster along trade routes and with Open Borders, and religious buildings and the religious civics speed or block that spread (manual, p. 78). A religion that reaches you this way works exactly like one you founded, except that you cannot build its shrine unless you capture its Holy City. Soren Johnson's afterword in the manual (p. 181) says religions first spread only by this hidden trade-based rule, which frustrated testers, so missionaries were added to give players control.

Missionaries

Missionaries carry a religion where you want it. Under the Organized Religion civic any city with your State Religion can train them; otherwise only cities with a Monastery of that religion can, per the manual, pp. 79-80. They need Open Borders to enter another civilization's land, and a civilization may have only a limited number at once.

Each conversion attempt uses up the missionary, whether it works or not. The odds are best in a city with few religions, since every religion already there lowers them, and a missionary spreads more easily into its own civilization's cities than into foreign ones; there is no limit to how many religions one city can hold (manual, p. 79).

State Religion

A State Religion is the one your civilization adopts on the Religion Advisor (F7). Every city that has it gets +1 happiness and +1 culture per turn, and the Holy City of your State Religion gets +5 culture more, which the manual (p. 79) recommends as a quick way to push early borders out. It also powers religious civics and buildings: Organized Religion builds 25% faster in cities with it, Theocracy gives new units +2 experience there, and Pacifism doubles Great Person birth there (manual, p. 90; see Civics).

Changing State Religion can cost turns of anarchy, except for Spiritual leaders, who switch civics and State Religion "with no anarchy" according to GameSpot's guide; see Leader Traits. Free Religion, from Liberalism, gives up the State Religion altogether for +1 happiness per religion in a city and +10% research.

Your State Religion also affects loyalty. Your cities flip more easily to a rival whose State Religion they share when it is not yours (manual, p. 48), and spreading your State Religion into a newly captured city is one of the manual's ways to keep it from slipping back.

Religion and diplomacy

Religion was meant to give diplomacy a reason. Johnson writes in the manual's afterword (p. 181) that a different State Religion breeds animosity while spreading yours can win a long-term ally. GameSpot's guide called religion "one of the largest factors in diplomacy": a shared religion is a plus in every AI leader's attitude, a "heathen" one a "huge diplomacy negative", and a Spiritual leader can switch religions to match a dangerous neighbor (GameSpot, Jan 18, 2006). Diplomacy lists the other factors.

Temples, monasteries, cathedrals and shrines

Religious buildings belong to one religion and can only be built where it is present, so a city with Judaism and Confucianism can have both a Jewish and a Confucian Temple (manual, p. 80).

Building	Cost	Needs	Effect
Temple	80	Priesthood	+1 happiness, +1 culture, 1 Priest
Monastery	60	Meditation	+10% research, +2 culture, trains missionaries; obsolete with Scientific Method
Cathedral	300	Music and three temples of that religion	+50% culture; +2 happiness if it is the State Religion; 2 Priests
Shrine	Great Prophet	The Holy City	+1 gold per city with the religion; spreads it; 3 Priests; more Great Prophets

Source: Warlords manual, charts pp. 129-138; GameSpot's guide, Jan 18, 2006; Civilization 4 manual, pp. 80-81.

Shrines are the money. Only a Great Prophet can build one, only in the religion's Holy City, and it then earns one gold every turn for every city on the map with that religion, yours or not (manual, pp. 80-81). GameSpot's guide advised founding several religions, building several shrines and spreading the faiths to foreign cities to "start earning". See Great People for how Prophets are born.

Cathedrals are capped by temples: one per three temples of the same religion, so seven temples allow two cathedrals (manual, p. 81). Their big culture bonus makes religion a mainstay of a cultural win; see the Culture Victory Guide.

The Apostolic Palace

Beyond the Sword added the Apostolic Palace, a Medieval-era wonder "with abilities similar to those of the United Nations (but with voting power determined by one's faith rather than one's size)", per the Beyond the Sword manual (p. 27). Steam's store page says it makes a UN-like body available "earlier in the game, providing a way to win a diplomatic victory earlier" (Steam), and GameSpot's preview described its builder pushing decrees that stop civilizations of the same faith from attacking one another (GameSpot, May 25, 2007). The manual leaves the details to the in-game Civilopedia.

Rendered view of a great domed church at sunset, a wide square ringed by columns and an obelisk standing in the middle of the paved square. — A wonder scene from 2K's Beyond the Sword page: a domed basilica behind a colonnaded square with an obelisk at its center. Firaxis Games and 2K

The final patch, 3.19 (Jun 11, 2009), fixed two of its rules: situations that invalidated the "Secretary General/AP Resident" now force the next vote to be an election, and captured cities no longer give a double bonus for the Apostolic Palace. Beyond the Sword's Gods of Old mod replaces the seven religions with seven Mesopotamian gods (Beyond the Sword manual, p. 39); see Scenarios.

What critics said

GameSpot's 2005 review found religion "intriguing" but not crucial, noting there is no religious victory (GameSpot, archived, Oct 2005). Two decades later, PC Gamer's review of Civilization 7 measured that game's religion against Civilization 4's, saying religion had "played a major part in each series game dating back to Civilization 4" (PC Gamer, Feb 3, 2025); see Civilization 4 vs 5, 6 and 7.

Frequently asked questions

What is the best religion in Civ 4? No religion is better than another in Civilization 4: all seven have identical effects, so the useful choice is which one you can found first and which one your neighbors share.

How do you found a religion in Civ 4? In Civilization 4 you found a religion by being the first civilization to discover its technology (Meditation for Buddhism, Polytheism for Hinduism, Monotheism for Judaism, Code of Laws for Confucianism, Theology for Christianity, Philosophy for Taoism, Divine Right for Islam).

What does a Holy City do in Civ 4? A Civilization 4 Holy City shows you every city with its religion, gets +5 culture when the religion is your State Religion, and is the only place a Great Prophet can build the religion's shrine.

How do shrines work in Civ 4? In Civilization 4 a shrine is built by a Great Prophet in a religion's Holy City and earns 1 gold per turn for every city in the world that has that religion.

How do you build missionaries in Civ 4? Civilization 4 lets any city with your State Religion train missionaries under the Organized Religion civic; otherwise a city needs a Monastery of that religion, and each missionary is used up by one conversion attempt.

Should you have a State Religion in Civ 4? In Civilization 4 a State Religion gives +1 happiness and +1 culture in every city that has it and helps relations with leaders who share it, while Free Religion trades it for +1 happiness per religion and +10% research.

What is the Apostolic Palace in Civ 4? The Apostolic Palace is a Beyond the Sword wonder for Civilization 4 that works like an early United Nations, with votes weighted by faith rather than size, and it can lead to an earlier diplomatic victory.