When a city is conquered, or acquired through a trade deal or other method, the player is prompted with up to four options of what to do with it:
- Annex the city into his/her empire
- Make the city a puppet
- Raze the city to the ground
- Liberate the city and give it back to its original owner
The first two options are always available, but the total amount depends on the city being captured, as not all captured cities are eligible to be razed or liberated. (Holy Cities and original Capitals, for example, cannot be razed.) When only one option is available, which can only occur when playing as the Venetians (who can't annex captured cities) or as the result of a glitch, that one option will automatically be chosen.
Also note that when capturing a city, it will go into Resistance for as many turns as there is Population left in it, which means that the city will not produce any resources or yields, because its citizens simply refuse to work for the occupiers. However, the city will not starve during resistance, either.
Annexed cities work much like founded cities. The player can choose what they produce, manage where their citizens work, purchase units and buildings, expand their borders by purchasing additional tiles, and so on.
Nevertheless, the city will have an Occupied status and generate extra Unhappiness as detailed here, and the population of the city will generate additional Unhappiness (1.34 per Population, instead of the usual 1). Building or purchasing a Courthouse will remove the additional Unhappiness (but not the normal Unhappiness from the citizens or the city itself), and the city will thereafter function as a normal city in your empire. Note that on lower difficulty levels, these penalties may be reduced.
Note however, that the player may also progress from a puppet to annexing; and from annexing to burning down any of their annexed cities at any time (except for some cities, see below), and this will reduce the population count, most likely reducing it past that of a puppet. On the other hand, player cannot convert an annexed city back into a puppet.
Puppeting a city is one of the most popular means of controlling conquered cities. Such cities are not controlled directly by the player, but rather by an "expert democratic government," charged with carrying out extensive reforms such as raising the standard of living and exterminating widespread corruption, and which is benevolently protected by your mighty empire. This state of affairs brings the following distinctions:
- You immediately acquire the city's territory and gain control of all its resources. That also means you can upgrade your units within this territory and the isolated city doesn't need to have a road or Harbor connection to the Capital for spending strategic resources on upgrading.
- You may station garrison units and air units in it, as in a normal city of your empire.
- You benefit from the city's yield production ( Culture, Gold, Science, and Faith) once the Resistance period is over. Note, however, that Science and Culture produced by a Puppet city suffers a 25% penalty!
- The city will continue to grow its Population and borders as a normal city. However, you have no control of these processes.
- You have no control of the production process in Puppet cities. Once the Resistance period is over, it will always produce something, which is either a building, or Wealth (after all possible buildings have been constructed). It will never produce units, though, nor will it attempt to produce any Wonders.
- You cannot assign the Population in Puppet cities. The "democratic government" thinks it's most prudent to assign them according to the Gold-producing setup. Very...democratic.
- Units and buildings cannot be purchased from Puppet cities, nor can territory. This is not the case if you play as the Venetians, though - then you will be able to purchase units and buildings, but not territory.
Puppet cities do not count towards the additional Culture requirement for acquiring new Social Policies or the requirement for National Wonders, and generate no additional Unhappiness compared to cities founded by their current owner. In addition, they do not affect your treasury negatively, as their focus is set to Gold focus.
Since a newly captured city enters a Resistance period and can't really do anything useful, it's advisable to make it a puppet for a few turns until Resistance ends instead of immediately annexing it. Another point of keeping a city as Puppet is if your empire is very large already, and has Happiness problems - mainly if you play for a domination victory.
Any puppet city can be annexed anytime by clicking on the city's banner (unless you're playing as the Venetians), and the city name can be changed while viewing the city.
Captured cities can be burnt down to remove them from the game completely. When this option is chosen upon the capture, the city will be treated as if it were just annexed (thus still causing a hit to Happiness), but the city will start burning, decreasing its population by one every turn. After some turns, depending on the size of the city, it will disappear and City Ruins will be left in its place. The territory it controlled will also disappear, and the land will become Neutral again. This is a good option to take if you have no interest in controlling the captured city or owning its land. The Huns raze cities at double speed.
At any point during razing prior to the city's destruction, you can stop the razing, which can be a useful tactic for reducing the Population of an annexed city to avoid Unhappiness without destroying it outright (this is good for cities with wonders in them). Technically, choosing the razing option automatically annexes the city, making the thinning tactic a bad choice if you intend to avoid annexation of captured cities.
The player may also choose not to raze a city when it is captured. Only annexed cities can be razed, which means that puppet cities must first be annexed before they can be razed.
Attacking and conquering a city lowers its population by 50% and destroys all cultural and defensive buildings in the city, as well as some of the other buildings the city had (this will not occur when acquiring a city peacefully). So it's advisable to, instead of annexing most of the time, raze the city and then build another one near the ruins to avoid dealing with Unhappiness or the Courthouse maintenance cost.
The downside is that doing so will cost time, production and food to be spent on building a Settler, as well as time for moving the Settler to such position and founding the city, and that razing a city will also destroy all of the remaining Population and buildings, including wonders, in addition to leaving the area it inhabited unclaimed, requiring radical border growth that will cost a lot of time and money, and may potentially result in another civilization placing a city in the location before it can be reclaimed.
Certain conditions will prevent a city from being razed. City-states and annexed cities that were once the original Capitals of civilizations cannot be razed. This is so you cannot prevent a civilization from being liberated by destroying all their cities.
In addition, the Indonesian civilization's unique ability guarantees the first three cities founded on continents other than ones containing other Indonesian cities cannot be razed. Additionally, founding a religion makes the city where it was founded impossible to be razed, as the city becomes holy for that religion. Finally, the player can never raze any of the cities he/she founded.
Alternatively, the player may also choose to disallow city razing by checking in "No City Razing" in the Advanced Game Options before starting the game.
Liberating a city means that the city you capture will be returned to its original owner, after which it will immediately be added back to its owner's empire as a settled city, allowing its owner to immediately have full access to the city's resources with no cost to happiness and no resistance.
When hovering over a city before attacking it, the tooltip will mention the liberation bonus, if liberation is possible. The player who eliminated a particular civilization can't liberate its cities later on.
When a city is liberated to an extinct civilization or city-state, they will be back in play, and they will vote for the liberator when the United Nations or World Leader election occurs, no matter how their relationship is at the time of the vote, provided they are still in play. You can liberate cities of extinct civs even if you were at war with them when they lost their last city. In case the city has been liberated more than once, the latest liberator will get the vote.
A city can only be liberated upon the capture. If another option is chosen, it will no longer be possible to liberate the city unless it is captured again. It is also not possible to liberate a city when you capture it from its original owner, making it impossible for the player to resurrect a civilization they conquered completely unless another civ later captures one of the extinct civ's cities from you and you then capture it back.
In vanilla Civilization V, liberating a city is possible only if the city was part of an extinct civilization or city-state. In order to "liberate" a city originally belonging to an existing civilization, it would have to be puppeted or annexed and then gifted to its original owner.
In Gods & Kings and Brave New World, you can liberate any captured city, whether or not its original owner has been eliminated. Unlike in vanilla, bringing a civilization back from the dead no longer guarantees diplomatic support from them.
Liberating a city-state will immediately start an alliance with the liberator and give the liberator a lot of Influence. (This will still decrease each turn, though, and by going under the limit, the alliance will then be cancelled.) Liberating a city of an extinct civilization will grant the liberator a relations modifier and open borders agreement for the rest of the game.
Liberating captured cities also helps improve diplomatic relations with all other nations by reducing the player's reputation as a warmonger if the player has earned one through the conquest of other cities.
Conquering city-states and the diplomatic victory
When a city-state is conquered, or otherwise joins another civilization (as per the Venetian and Austrian civilizations' special abilities), this affects the diplomatic victory. First, the total number of Delegates required to win the World Leader vote diminishes by 1. Second, the one or two delegates (depending on the World Congress Era) associated with this city-state simply become unavailable - no nation can use them in further votes anymore, even the one that conquered or otherwise acquired the city-state. It is as if this city-state stopped existing as an individual entity in the diplomatic world.
Later, if the city-state is liberated, it rejoins the fray and its delegates reappear (automatically joining the delegation of the nation that liberated them). The total number of delegates required to win the World Leader vote also goes back up by 1.
Note that cities that joined Venice or Austria via their special abilities can never be liberated! In this case, the change in the delegate count is permanent.
Overall this complicates the achievement of a diplomatic victory, because after the Modern Era each city-state lost detracts two possible delegates from the wannabe Leader, while the overall delegate count required to win the vote diminishes only by one. This forces the nation attempting a diplomatic victory to rely on other sources of delegates, such as bonus delegates from declared World Religion and Ideology, the bonus delegates won from the Globalization technology, or a number of other possibilities. As such, it is a viable strategy for a nation trying to prevent an adversary from winning a diplomatic victory to attempt to conquer as many city-states as possible, so as to diminish the delegates available.