Purchasing is the ability to spend an accumulated resource (模板:Gold6 or 模板:Faith6) to acquire instantly something in a city. Purchasing by either 模板:Gold6 or 模板:Faith6 has its own tabs, along with the Production queue. You may Purchase instantly two types of game elements:
- Buildings, from the City Center or any District, as long as they are unlocked (have their requirements fulfilled). Districts may not be Purchased. Buildings are usually Purchased with 模板:Gold6, unless they are Religious buildings (such as the Temple), in which case they may also be Purchased with 模板:Faith6. The only buildings that can't be Purchased at all are City defenses (such as the Ancient Walls) and, of course, Wonders. Purchased buildings appear in the relevant District right away, and start functioning.
- Units. Most units may be Purchased with 模板:Gold6, with the exception of some special units such as the Spy. Some units may only be Purchased with 模板:Faith6: this includes the three types of Religious units, and the Naturalist. If you are in the Theocracy government, you may also Purchase military units with 模板:Faith6. Note that the cost of Purchasing Civilian units goes up with each unit Purchased, following the same scaling rules as with Producing them (this is valid for both gold and faith purchases)! So, as the game progresses and you keep Purchasing or Producing a certain type of unit (for example, a Builder), its cost will rise far above its Base value.
In general, the 模板:Gold6 cost of an item is 4x its current 模板:Production6 cost, while the 模板:Faith6 cost is 2x the 模板:Production6. Discounts to 模板:Production6 costs applied by gameplay elements (such as Policies) do not affect the Purchasing costs. Note that in cities with Military Academy or Seaport you can also purchase Units as Armies/ Fleets, etc. however, their cost will be double the normal cost for Corps/Fleet, and triple for Army/Armada. In this case it is cheaper to Produce the units, since their 模板:Production6 cost receives a discount from the above-mentioned buildings, and comes out as less than double/triple.
Note that, in the case of unit purchases, the place where the unit will appear needs to be 'free' - that is, no other unit of the same type may be present there. So, for example, if you have a Builder in the City Center, and you try to Purchase another one, or a Settler (which is again a Civilian type of unit), you will be told that you can't do it. The same is valid for Military units, although they may have the additional option of appearing in an Encampment District.
The final type of production in a city are Projects - conceptual undertakings, which use the city production system, but don't pop up physical things, such as units or buildings. Instead, they provide different benefits!
Along with the usual Projects, related to the Space Race, or to developing nuclear capabilities, Civilization VI introduces a number of regular Projects, such as Holy Site Prayers, which are related to the Specialty Districts, and may only be undertaken if the city has these districts. These Projects run for a set number of turns, and when finished produce a large amount of some stats, and usually some specific Great Person points.
As in previous games, every city pushes your empire's territorial boundaries. At foundation, it annexes all tiles surrounding the City Center (which are still free). Further expansion is again controlled by the amount of 模板:Culture6 the city produces. Note that, barring exceptional circumstances, even newly founded cities now produce a small amount of 模板:Culture6 from their 模板:Citizen6 Population, and will thus grow their borders eventually.
You can visualize the next tile the city's territory will grow to by activating either the Citizen assignment, or the Tile Purchase option of the city command tab. The tile will be displayed in purple, and the number in it will show in how many turns the growth will occur.
Tiles may also be purchased with 模板:Gold6. This is now done straight from the city options on the main screen. You may purchase any tile which is found right next to the current boundaries of the city; the farther the tile is from a City Center, the more expensive it is. Unlike in Civilization V, Resources don't seem to affect the price of tiles. Again, you may only purchase tiles up to three away from any City Center - further tiles may only be annexed via normal Cultural expansion.
Being a civilization's main manifestation, a city is always a target for military action. That's why it's also important to consider how a city can defend itself from enemies.
In Civilization VI early cities are quite weak, because they lack any defensive structures. Unlike in previous games, without defensive structures a city cannot use a Ranged Attack to damage invaders. It will still damage attacking units in retaliation to melee attacks, though.
But there are additional vulnerabilities to cities in Civilization VI: because their districts are now physically located on other tiles, cities may now become severely crippled by invading armies, even if they don't attack the City Center. Invaders now are able to pillage nearby districts, crippling other aspects of the city production, and setting an empire back even without taking its territory. Each time a Pillage action is triggered on a District tile, one Building in this district will be disabled; if there are no functioning buildings left, the District itself is disabled! Disabled buildings and districts have to be Repaired, using a special action in the city's Production queue. Repairing a whole District is quite expensive, while individual buildings take less time to fix.
For more information on city combat, head here.
Where to Construct Cities
Cities should be constructed in locations with plenty of and 模板:Production6 and with access to Strategic, Luxury, and Bonus . It is often a good idea to build a city on a or coastal hex, as sources of water are very important to a growing Population. Cities constructed on gain a defensive bonus, making it harder for enemies to capture them.
The exact location of the City Center shouldn't consider yields, just strategic access (and eventually, whether there is a Resources on it). This is because of the change in yield the city forces on the tile. In fact, the best possible yield for a City Center without a Resource on it is 2 , 2 模板:Production6, and this may only be obtained by settling on a Hill in Plains. For any other terrain, the yield will be 2 , 1 模板:Production6, even in Desert or Snow. In fact, you may find it worthwhile settling in such inhospitable terrain, as long as nearby tiles have better yields! This way you will practically force a tile without yield to acquire one, and still preserve better tiles for use by your 模板:Citizen6 Citizens. Normally, you should also leave tiles with Resources to be outside the center, because later you can build Improvements there and increase the yield. Settle on top of resources just in extreme cases, when other strategic factors warrant it.
Cities built on a Coastal tile will be able to build ships, once you've researched the right technologies. Cities built within 2 tiles of Coastal water, or a Lake, will be able to construct a Harbor District (once their borders have grown to the water tile), and then they too may build ships. Any civilization which wishes to develop seafaring must have at least one city with conditions to build ships.Civilizations which have special sea-oriented Abilities, such as the Norwegian and English should consider settling cities on the Coast a priority.
With a selected, ideal city locations will be shown on the map with an icon. Additionally, every Settler will show the Settler Lens (for the first settler, you can activate it with the filter button on the top of the minimap), giving you an idea of where on the map will provide the best source of water for your city, and indicating unavailable tiles.
Choosing the exact location for a city is actually so complex that it almost amounts to an art. With all of the above recommendations, there are still a ton of other factors to consider: location in respect to your other cities, in respect with rival civilizations, nearness of Resources, etc. etc. It is only after you acquire experience playing the game that you will be able to place your cities in the best locations strategically.