Merry Christmas everyone. It seems like as good a time as any to start adding in Religion. We'll start with Christianity which is the religion I'm the most familiar with and found the easiest to find a core identity for.
Christianity in this game is based around the Catholic Church as a wealthy political institution, and focuses largely around funding, art and holy war.
DRAFT - Christianity & its Tenets
Terminology & Mechanics
Founders and Followers:
Timeline distinguishes between the Founder(s) of the religion and those who follow it. The Founder of the Religion is the Player that created the Religion, + any other Player that owns a Holy City while also having that Religion as their State Religion. These players benefit from the
FOUNDER BELIEF.
The
FOLLOWER BELIEF affects anyone who follows the Religion as its State Religion. It doesn't require majority Religion in most cities, although some Tenets will scale based on / exclusively interact with Majority Cities and Follower Count. Followers can become Founders if they obtain or designate a Holy City belonging to their Religion. There are plenty of ways to doing this, depending on the Religion. Vedism and Islam can very reliably obtain more Holy Cities, while Tengriism doesn't have one at all, with every Follower counting as a Founder.
Populations that belong to a certain Religion will also be called '
Followers' down the line.
Worship Buildings and the Grand Temple:
The Founder and Follower Belief, as well as the
Worship Building (the Tier 3 Grand Temple) are unique to each Religion. Some Religions have additional variants of existing buildings, such as Islam's
Madrassah and Vedism's
Gurdwara. Christianity, which we'll talk about first, only has one type of Grand Temple, the Cathedral. Churches and Chapels are refered to as '
Christian Temples' and '
Christian Shrines' for clarity.
Tenets
The other key mechanic of Religion are the unique
Tenets every Religion has access to. Tenets are unique to their Religion, with the caveat that Religions can have Tenets with similar effects. Some Tenets can exist for other Religions in weaker forms. Christianity for instance has a Coin focus, and Coin-based Tenets in other Religions are weaker or less numerous, to help cement Christianity as the Religion of material wealth.
Tenets offer a broad range of buffs that could play into your Civ's strengths, or give you guidance towards how to win the game.
For a Tenet to take effect, it has to be
adopted, just like how a Policy Card would be slotted in Civ6. Religions have a limit on Tenet slots, but Founders have the ability to expand the amount of Policy Slots via certain actions.
There is no theoretical cap to how many Tenet slots you can obtain in a game. The exception is
Judaism, which is permanently capped at 10 slots, but has them all unlocked from the start.
Denominations, the Ecclasiastical Council and Schisms
All Players that follow the Religion will benefit from adopted Tenets. Tenets can be Discovered and adopted by expending a Great Prophet. If a Founder adopts or renounces a Tenet, the effect is automatically applies for all players who follow that Religion. If a NON-Founder adopts a new Tenet or renounces an old one, a vote will happen between all practitioners called the '
Ecclesiastical Council'. This is a World Congress Vote between only practitioners of the Religion. If the change is rejected and the player who proposed it defies the decision, a
Schism will happen, and that player will found a new
Denomination of the Religion, with them as the Founder. This can happen up to twice in a game per Religion.
Practioners can choose which Denomination they follow. This will decrease Relations with rival Denominations but greatly boost Relations within their Denomination.
Denominations of the same Religion have the SAME Founder and Follower Beliefs and the SAME Worship buildings. All that Denominations differ in are adopted Tenets (there is some overlap but it's no longer universal) and which players have Founder and Follower status.
How to obtain Tenets:
Tenets are discovered via Great Prophets. Discovery works like it does in Hearthstone - the game randomly picks three Tenets to show to you, and you pick one of the three. One of Christianity's features is that it will be able to see
five Tenets instead.
Typically, players can only discover Tenets of their own State Religion, but they ARE allowed to add Tenets of other Religions if they know them. (this may upset the Founders depending on their Leader's Personality). It is possible to discover Tenets of non-State Religions if you own a Prophet of that Religion.
Each Religion has a group of Interfaith Tenets that they share with other Religions (dual-type Tenets, if you will), as well. Henry VIII is able to discover Tenets of any Religion present in his empire, and add it to his State Religion through by-passing the Ecclesiastical Council. Since Henry cannot found Religions, this will nearly always result in a Schism.
How to obain Tenet slots:
The Ethics tree will contain additional Tenet slots as potential Tech Rewards. The 'Reformation' ability on Great Prophets will offer their owner the choice between discovering a new Tenet or adding another slot to their Religion. Additionally, I'll ensure there is at least one World Wonder that rewards Tenet slots.
Clerics
The Civilian units tied to Faith, the
Clerics, will all follow a Religion that you can choose yourself. The Cleric's abilities will then work towards that Religion. If the Religion has experienced a Schism, you'll have to assign a Denomination as well. Henry VIII, who cannot earn Great Prophets, can instead Discover Tenets via his Clerics. (expending them as other players do Great Prophets).
Heretics, Heathens, Pagans and Faithful
Finally,
Heretics are players that follow the same Religion but a different Denomination.
Heathens are players that follow a different Major Religion.
Pagans are players that either don't have a Religion, or follow
Tengriism.
Faithful are players of the same Religion AND Denomination as you.
Advantages: Provides players with the Guidance they need to execute their strategy.
Disadvantages: Poor relations. Religions put a lot of strain on diplomatic relationships, with both Heathens and Heretics, and can make befriending other AIs very difficult. If you want to stay friends with everyone, consider converting to the most prominent Religion or staying irreligious.
The plan long-term will be to add Ideology to the game, which is a way for non-Religious Civs to have a Religion-like mechanics without having to commit to Faith and piety. This won't be introduced for a while however.
Important Reminders before we jump into Tenets:
- All Clerics and Worship Buildings mentioned below are Christian unless stated otherwise. If a Tenet's effects apply only to Denominations (either the player's, or all but the player's), it will specified.
- In order to benefit from the Founder Belief you either need to own a Holy City, or be the player who Founded the Religion, while also following the Religion.
- Any player that has the Religion as its State Religion will benefit from the Follower Belief and the Tenets.
- ONLY Players who Found a Religion can retain their Pantheon bonuses, and only as long as they have it as their State Religion. (This applies to any Religion that Player has founded in a game.)
- Bon-Pagan Worship Buildings (Shrine, Temple, Grand Temple) can be built as soon as one Population in a City has Converted to the Religion. Pagan Worship Buildings and Pantheon bonuses will become unavailable once the City has a Majority Religion. If you Founded a Religion that is your current State Religion, the Pantheon bonuses will be retained.
- Factions with a unique Pagan Worship Building (such as Ptolemaic Egypt's Serapaeum), will be able to retain it as a Variant, but only for their State Religion. If Cleopatra follows Buddhism, the Serapaeum will count as a Buddhist Temple only.
CHRISTIANITY
Founder Belief (Sancta Sede): Christian Holy Cities receive extra
Coin and
Culture per Christian Tenet slotted. Receive a

Tenet slot whenever a

Religious World Wonder is built in a Christian Holy City. Whenever you discover a Tenet, see five Tenets instead of three.
Follower Belief (Tithe): Christian Temples and Cathedrals generate extra
Coin from Christian Followers in their City.
Worship Building (Cathedral): One additional Display slot. Can Display
Art. All Art put on Display here doubles as a Christian
Relic, generates
Coin in addition to
Culture, and attracts
Pilgrims as well as
Tourists.
Core Identity & Tenets
Clerics as Governors: Christianity offers several Tenets that improve City Yields passively if a Christian Cleric is stationed inside the City.
- ANOINTMENT: Clerics can prevent Disease Outbreaks in their Cities.
- BAPTISM: Clerics exert more
Religious Pressure when stationed inside a City with Fresh Water.
- BEATIFICATION: Clerics increase the
Tile Appeal and
Wonder Tourism in their Cities.
- CARDINALIS: Clerics increase the
Coin income in their Cities by a set percentages, schaling with the amount of Promotions they have.
- CONFESSION: Clerics decrease the success chances of enemy Espionage or Secret discovery in their vicinity.
- EUCHARISTIA: Clerics increase the
Faith income of their City based on the amount of Followers in that city.
- INDULGENTIA: Clerics increase the
Coin income of their City based on the amount of Followers in that city.
- JESUIT EDUCATION: Majority Cities or non-Majority which a Cleric is stationed may spend Faith to buy a Blueprint towards an Education Building of choice. The cost goes up by a set percentage each time you use this.
- LAIETY: Decrease the
Faith cost of Clerics by a small percentage.
Holy War: Christianity offers bonuses to Military Combat Strength and Health/Morale recovery rates near Christian Cities, irrespective of their owner. Christianity also receives Tenets that allows them to straight up disrupt other Religions, including other Christian Denominations (Heretics).
- CONTRA REFORMATIO: Military units have more Offence against Heretics in Foreign Lands.
- CRUSADE: Military units have bonus Strength against Heathens, more near Heathen-controlled Holy Cities.
- DEUS VULT!: Military units have increased Offence against Heathens in Foreign Lands.
- EXCOMMUNICATE: Your Clerics surpress the effects of foreign Clerics when stationed in an owned Majority City.
- LAST RITES: Increase morale recovery in foreign lands.
- LAY ON HANDS: increased health recovery in foreign lands.
- SALVATION: Increase
Food from Military buildings, which are also cheaper to construct.
Church Power: The Christian Church likes to flaunt its wealth, and several Tenets will enable you to build dazzling cities, or reward you for playing towards Culture Tourism Victory.
- CYRILLIC SCRIPT: Increased
Knowledge and
Religious Pressure from
Scriptures. Every Christian player receives a
Scripture when this Tenet is adopted.
- ENCYCLICALS: Cathedrals can display
Literature. Any
L iterature displayed there yields
Faith and
Production in addition to other Yields and counts as Religious.
- ICONOCLASM: Worship buildings with empty Display slots yield more
Faith per empty slot.
- ICONOPHILIA: All
World Wonders in Christian Holy Cities are considered Religious. All
Worship Buildings receive 1
Display Slot towards a Relic or Scripture.
- PATRIARCHY: Increased
Faith and
Coin on Wonders, more if they're Religious.
- RETROTABULUM: After you successfully complete any Religious Wonder in a Majority City, receive a
Great Artist.
- VADE ET VINCE: The Ecclesiastical Council will designate an additional Christian Holy City after adopting this Tenet, and every second Tenet after this one. Each vote will be held between the two most eligible Cities. Cities belonging to the owner of the previously designated Holy City aren't eligible for this vote.
- [The Holy Cities will be picked via a set of IF-statements, with Follower Count, amount of Religious Wonders and Location being taken into account
Interfaith Tenets:
- GENESIS: (Shared with Judaism) Whenever a majority City has a
Growth event, add a small amount of
Culture and
Coin to Worship buildings for a set amount of turns.
- GOD IS GREAT: (Shared with Islam): A portion of military upkeep costs are paid for with
Faith instead of
Coin.
- ICONOGRAPHY: (Shared with Vedism): Increased Architectural Wonder
Construction speed in Majority Cities.
- LOVE THYNE NEIGHBOUR: (Shared with Zoroastrianism) Clerics exert more
Religious Pressure to foreign border Cities. Improved
Relations with Players whose Cities receive extra Christianity Pressure from this Tenet.
- MISICATENGRIN: (Shared with Tengriism) Whenever you complete a World Wonder in a Majority City, discover a Christian Tenet
- MONASTIC ORDERS: (Shared with Eastern Zen) Receive a Knighthood for every second Cleric you recruit after adopting this Tenet.
- PREDESTINATION: [Shared with Buddhism]: Whenever you would receive something at random,
Discover between three eligible options instead.
Flavour Tenets:
- CARITAS: Majority Cities have increased
Faith based on their
Coin output.
- ECUMENISM: Increased
Relations with other Christian players, irrespective of Denominations.
- EXCELSIOR: After you have converted a set number of Heathen or Pagan Cities to Christianity, trigger a
Festival in the Majority City with the most Followers.
- KYRIE ELEISON: Increased
Faith,
Housing and
Amenities from Medical buildings.
- NATIVITY: After completing a
Festival, increase
Relations with other players by +1 for a short amount of turns.
- OPUS DEI: Christian Holy Cities receive bonus
Production per set amount of Followers in other Countries.
- PENTECOST: Trigger a
Festival in all Majority cities a set amount of turns after earning a
Great Prophet. (49 turns on Standard)
- PURITANISM: Worship buildings no longer provide Amenities, and instead increase Food and Production for every Amenity they otherwise would have given.
- SCHOLASTICA: Monastery improvements yield extra
Knowledge
- SOLEMNITY: Worship buildings grant double

Amenities during Festivals.
The list is tentative, so more Tenets may be added later, while others might be tweaked. I'll slowly fold the Religions in, with the next one being
Islam.