Every city has a culture level: Weak → Developing → Strong → Legendary. Culture accumulates per city from buildings, specialists, projects and events; when it reaches the level's threshold the city advances (and fires a culture event). Higher culture is worth more Victory Points, unlocks better wonders, buildings, units and projects — but each Citizen consumes more to sustain the lifestyle.
| Level | Culture to advance | VP per city | Governor XP/turn | Citizen consumption | Level-up project |
|---|---|---|---|---|---|
 Weak | 100 | 1 | 4 | -1  /Pop | Council I |
 Developing | 500 | 2 | 6 | -2 /Pop -1  /Pop | Council II |
 Strong | 2,000 | 3 | 8 | -3 /Pop -1 /Pop -1  /Pop | Council III |
 Legendary | 5,000 | 4 | 10 | -4 /Pop -1 /Pop -1 /Pop -1  /Pop | Council IV |
Culture to advance is iThreshold — the culture a city
must accumulate to leave that level (100 to go Weak → Developing, … 5,000
to advance past Legendary). Beyond Legendary each further culture
step costs 5,000 × (steps + 1) and is worth +1 VP apiece
(countCultureStepVPs). Governor XP/turn is the XP a
governor earns each turn from the city's culture level
(culture().miXP). The level-up project (Council
I–IV) is the city's default/shortfall project at that level.
Culture prereqs across the rest of the XML, grouped by the level that gates them. Tiered city projects (Council, Festival, Decree, Inquiry, Hunt, Olympiad, Convoy) require the city to be at exactly that level; Treasury / Forum / Archive tiers require at least that level.
Weak 
Market Developing 
Library
Courthouse Library 
Temple · Holy Site 
Stele · Aksum Stele Temple of Solomon · Holy Site Strong 
Amphitheater · Odeon 
Cathedral · Cathedral Cathedral · Cathedral 
Citadel · Garrison Stele · Aksum Stele Cathedral · Cathedral Cathedral · Cathedral Cathedral · Cathedral Cathedral · Cathedral Legendary Stele · Aksum Stele 
Palace · Courthouse 
University · Library Culture-tier units come in pairs: the Developing-tier version (Battering Ram, Hoplite, Hastatus…) goes obsolete at Strong, replaced by its Strong-tier upgrade (Siege Tower, Phalangite, Legionary…). Buildings and wonders also need their tech and other prereqs — only the culture gate is shown here.
| Level | Extra capture turns | Extra assimilate turns | Assimilation per turn |
|---|---|---|---|
| Weak | +0 | +0 | −1 |
| Developing | +1 | +10 | −2 |
| Strong | +2 | +20 | −3 |
| Legendary | +3 | +30 | −4 |
A captured foreign city starts at 20 base
assimilate turns plus the founder's culture bonus, and yields
are modified by -50% until assimilated;
the countdown ticks by the city's current culture level each turn
— higher culture assimilates faster (City.cs,
doPlayerTurn). Extra capture turns stack on the base
2 — full formula on the
City Capture Mechanics page.
Despite the name, development.xml has nothing to do with
city development. It defines the Development game-setup option
(advanced start): how developed existing (AI) nations are when
the game begins — average cities, capital population and free techs —
plus how many turns the AI holds off building wonders and founding
religions.
| Setting | Avg cities | Capital pop | Free techs | AI no-Wonder turns | AI no-Religion turns | Notes |
|---|---|---|---|---|---|---|
| Default | — | — | — | — | — | The player receives the default number of Cities and Technologies for the currently selected game options. |
| None | — | — | — | — | — | Existing Nations don't start with any extra Cities or Technologies. |
| Fledgling | 2 | 2 | 2 | 5 | 4 | Existing Nations start with an average of 2 Cities and 2 Technologies. |
| Established | 3 | 3 | 3 | 10 | 8 | Existing Nations start with an average of 3 Cities and 3 Technologies. |
| Advanced | 4 | 4 | 4 | 15 | 12 | Existing Nations start with an average of 4 Cities and 4 Technologies. |
| Massive | 5 | 5 | 5 | 20 | 16 | Existing Nations start with an average of 5 Cities and 5 Technologies. |
Source: culture.xml (thresholds, VP, XP, capture/assimilate
modifiers, EffectCity, Council projects), effectCity.xml
(per-Pop consumption), improvement.xml / unit.xml
/ project.xml (CulturePrereq,
CultureObsolete, RequiresCulture,
MinimumCulture), development.xml,
globalsInt.xml; semantics from City.cs
(growCulture, canDoProject),
Player.cs (countVP) and
Character.cs (governor XP).
