What Buildings are Destroyed When a City Changes Hands?

[Halcyan2]

When you capture a city through conquest, there is a percent chance that some buildings are destroyed.

However even if you gain control of a city through trade or through a peace deal, some buildings still disappear:

1. It looks like defensive buildings (walls, castle) automatically go away even if the city is peacefully taken.

2. Pre-BNW, all cultural buildings were lost when a city changed owners. Post-BNW, most cultural buildings (with great work slots) stay intact though they can still sometimes get destroyed if you conquered the city.

3. I have noticed that some Unique Buildings get destroyed.

Right now the popular consensus about UB's is that: If your civilization has a UB and you capture a city with the normal building, it automatically becomes the UB. If a normal civilization captures a city with a UB then it gets converted into a normal version of that building.

Here is the thing: I am currently playing a game with a minor custom mod. Made it myself. It has very minor changes which I do not think should be significantly impacting the way the game works. In particular, I made a custom civilization that has two unique buildings (which already exist) - the Stele and Royal Library.

So the thing I am noticing is that whenever I take control of a city with a Monument or Library it is converting to a Stele or Royal Library (which is expected). However, whenever my city (with Stele or Royal Library) becomes owned by another civ (including as part of a peace deal), the Stele or Royal Library is instantly destroyed (not converted into a normal version).

Assyria happens to be in this game, and even though we both have Royal Libraries, they still get obliterated if control of a city changes. And it also applies when my custom civ is not involved. (Carthage got Ninevah in a peace deal. The Royal Library got obliterated, but the city retained its university but no library).

On a different note, I did see that in Baghdad (originally with Arabia's Bazaar UB) the Bazaar did successfully convert into a normal Market. Which makes me wonder if it's something special with the Stele and Royal Library. Or my mod somehow messed things up (even though it is fairly simple and I don't think it should).

So anyone else have experiences with UB's disappearing (and not getting a normal replacement) when a city changes control?

 

[Acken]

Well according the XML table for buildings. Some like walls have the NeverCaptured attribute set on true.
Other buildings have a ConquestProb attribute being set on 100 for wonders and 66 for most of what I see.

UB have the building class of their replacement (Stele has the BUILDINGCLASS_MONUMENT type) and some of them like the stele are set on NeverCaptured. The bazaar however is set on 66% probability.

There doesn't seem to be a real logic behind this besides the capturable being from Vanilla. Which would mean this is probably just sloppy coding from Firaxis.

 

[Halcyan2]

Thanks for reminding me of the XML files. It seems there are two possible variables (which are not always present for each building/wonder).

1. As you've noted, World Wonders have 100% ConquestProb, so you always get them if you gain the city.

2. Most National Wonders have the NeverCapture flag set to True. The exception are the three Guilds which don't have that variable, which explains why players who don't have a Guild have been able to capture one from another player.

3. Generally, most buildings have a Conquest Prob of 66%.

Some have a Conquest Prob of 0%:

Monument
Anti-Espionage (Constabulary & Police Station)
Military Training (Barracks, Armory & Military Academy)
Defensive (Walls, Castle, Arsenal & Military Base)

Furthermore, the Courthouse has NeverCapture set to True.

In contrast, a few buildings have a Conquest Prob of 100%:

Great Work Buildings (Amphitheater, Opera House, Museum & Broadcast Tower)
Most Religious Buildings (Cathedral, Mosque, Pagoda)

* Before the last patch, there was an issue with Amphitheaters commonly getting destroyed. BNW gave them 100% ConquestProb but did not remove the NeverCapture = True. The last patch seems to have helped and Amphitheaters commonly are retained. However, I have still seem them destroyed on at least one occurrence. (Conquered Rio de Janeiro from Brazil, who had never lost it. The city came with an Opera House but no Amphitheater).

4. As for Unique Buildings, most of the ones from the base game have the same 66% Conquest Prob their normal counterpart has, including:

Floating Gardens
Longhouse
Bazaar
Satrap's Court
Paper Maker
Wat
Mud Pyramid Mosque
Burial Tomb

From the expansions, these also have the same 66% as their normal version:

Candi
Hanse
Maya Pyramid

The Ikanda and Stele have NeverCapture = true, which is consistent with the Barracks and Monument having the same flag value.

The Ceilidh Hall has 100% ConquestProb, which is consistent with the Opera House.

Discrepancies that I am seeing include:

- Ducal Stable has 0% ConquestProb, whereas the normal Stables doesn't seem to have that variable defined at all.

- Royal Library has both NeverCapture = true AND ConquestProb = 0%. Whereas the normal Library (and the Paper Maker UB) both have a standard 66%. This explains why I've been seeing Royal Libraries getting destroyed.

- Mughal Fort and Krepost don't seem to have any of the relevant variables defined, whereas their normal counterparts have NeverCapture = true.

- While the newer Religious buildings have 100% Conquest Prob, it doesn't look like Monasteries were updated. As a result they seem to still have the old 66%.

So my new questions are:

A. How often normal Stables get destroyed or are kept in conquest?

B. Any guesses why Royal Libraries are destroyed upon conquest (when Libraries and Paper Makers aren't)?

C. What happens when Mughal Forts and Kreposts get captured (kept/converted or destroyed)?

D. Can anyone confirm whether Monasteries can get destroyed if captured?

 

[Tapio]

But does cultural influence also effect this?

 

[Halcyan2]

But does cultural influence also effect this?

I don't know.

For some things (like the NeverCapture flag), it applies even if you get a city through trade or through a peace deal. So in those cases, all of the normal buildings are intact (and don't suffer the Conquest Prob possibility) but nonetheless buildings with the NeverCapture flag (defensive buildings, Monument/Stele, etc.) will still get destroyed. So I don't think that cultural influence through tourism will affect those.

I have no idea whether cultural influence changes the Conquest Prob when you actually take a city through war though. I would imagine not, but I could be wrong.