Why Are Some Cities More Vulnerable to Spies?

Background is that I had met Byzantium and Sweden. Some other Civ which I hadn't met reached the Renaissance Era so we all got spies.

Our capitals all had 11 population. I put my spy in Stockholm.

I had construction stolen when I had 15 turns to go before I could have a chance of stealing anything.

Why was my capital so vulnerable given that all Civs I knew (and it had to be one of them) were not especially advanced?

http://civilization.wikia.com/wiki/Espionage_(Civ5)

Broadly, the more science a city is producing, the quicker it is to steal technology from, However security buildings provide some defences, as to counterespionage agents.

If you are looking to steal tech, aim them for the ones with the most star ratings, as they'll be the highest science producers. If you are ahead in tech, don't bother as you can only steal a technology they have acquired but you haven't.

If you want to prevent tech theft (or at least improve chances of doing so) place them as security in your highest science cities. Bear in mind this is usually not optimal use of spies though, and unless you already have 100% alliance with all city states, you're better off using them for that.

AI almost never sends a spy to a non capital city, so your capital is the only city in which you need security.

Unfortunately you have to build Police Stations in every city (puppets excluded) to build the NIA though, but you can sell them off of the non capital after completing it to stop wasting maintenance costs just like you can sell off the extra barracks you needed for Heroic Epic after you complete HE.

Note that the main reason for NIA isn't actually spy defense but the extra spy, especially when going diplomatic victory.

Thanks for the replies. However, I do have difficulty with the replies.

Joncnunn, I tend to disagree with the AI rarely going for secondary cities. I have frequently had technologies taken from 2nd and 3 rd cities- especially if I have a killed a number of spies in my vapital. I would add that I prefer to pay wide.

Asklepios, I understand the cities with the highest number of stars are the best targets but we are talking the first spies in the game and at that point there was no knowledge of the ratings of any city apart from my own. It was also too early in the game for constabularies or other preventative buildings.

So, the bottom line is I had a capital the same size as the AI's. My city had a library but nothing else that would generate a huge potential (that I know of). Yet a recruit spy was able to steal technology from me 15 turns before I could take one. That is a massive difference.

On high difficulty level you often need to play the catch-up game, the AI often obtain the first spy earlier than you, during this time it's easier to steal tech. There is no method to prevent it unless your tech is way too slow in which case there is no point stealing from you.

Versaguy said:

On high difficulty level you often need to play the catch-up game, the AI often obtain the first spy earlier than you, during this time it's easier to steal tech. There is no method to prevent it unless your tech is way too slow in which case there is no point stealing from you.

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That may explain it. I thought we all got the first spy at the same time.

Convict said:

I tend to disagree with the AI rarely going for secondary cities. I have frequently had technologies taken from 2nd and 3rd cities- especially if I have a killed a number of spies in my capital.

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That is my experience as well, but your OP is about the beginning of the game. Also, I am often the one trying to catch up. Some games I have 3 spies in the largest cities of a single civ opponent.

Yet a recruit spy was able to steal technology from me 15 turns before I could take one. That is a massive difference.

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Yeah, it's frustrating. But this is usually associated with the player being ahead tech-wise.

Convict said:

I thought we all got the first spy at the same time.

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You did, I think you misunderstood Versaguy's reply. What difficulty level are you playing at?

Convict said:

Thanks for the replies. However, I do have difficulty with the replies.

Joncnunn, I tend to disagree with the AI rarely going for secondary cities. I have frequently had technologies taken from 2nd and 3 rd cities- especially if I have a killed a number of spies in my vapital. I would add that I prefer to pay wide.

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The last time I had a tech stolen from a non capital was back in the G&K days and even then it only occurred once involving a situation where the non capital was next to a mountain and my capital wasn't.
(I play tall tradition and indeed scrap all spy defense buildings that were needed for NIA in non capital cities. )

Yes, the stars shows the relative vulnerabilities. The AI though actually does NOT know the spy value in advance. I can't rule out them guessing via population size. (In BNW, the capital of a tall empire is bigger relative to the other cities even than it was in G&K due to food cargo ships.)

So why do you think it took ai so little and you so long? Use your own intelligence... for example, ais in the higher difficulty are less likely to steal from you since higher difficulty ais make e more technology. Constabularies and police stations increase the turns it takes an ai to steal.

There are some tips for spying from my experience:
1. Never spy the tech run-away AI. They definitely put one of their spy in their capital. If you feel there is not much to steal from others then spy on their second most pops non capital city. It is slower but at least you got something
2. Spy the higher tech AI that is also a warmonger to boost diplomacy with others
3. Spy the advanced tech neighbor that also looks like they might attack you
4. Understand the AI's priority tech based on their unique units/building and plan your technology well to maximize spying value. For example England tech is often education-machinery-navigation you may research civil service then wait to steal education, then the 2nd round research observatory to steal navigation. However if England are the top 2 advanced AI dont spy them or your spy get killed.
5. Spy on capitals of the wonder spammer in your games, could be France or Egypt. Once I was spying on Paris I got one tech in every 10 turns.
6. When they ask not to spy on them again dont agree unless your relation is so bad that they might attack if you dont. Keep spying on them until they reach another era and get another spy, this time they will put this spy in their capital. Moving spy to other civ's city very time-consuming so avoid to do so unless they already prepare with another spy or a constanbulary.

reddishrecue said:

So why do you think it took ai so little and you so long? Use your own intelligence... for example, ais in the higher difficulty are less likely to steal from you since higher difficulty ais make e more technology. Constabularies and police stations increase the turns it takes an ai to steal.

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I've already mentioned this is too early in the game for anyone to have constabularies or police stations.

Oh man, in my current game, there was a time around the Renaissance/early Industrial that a tech was being stolen from me roughly every five turns. I was Spain and had Recruit Garcia in Madrid but he couldn't catch whoever was doing it and so couldn't promote. Finally, by chance he did manage to kill an enemy spy (probably a Special Agent by then) and got promoted. From then on he managed to kill more, although techs would still get stolen every now and then.

Finally, when I got an ideology I picked Order and chose Double Agents. And from that point on, Special Agent Garcia totally went to town on everyone else's spies. At this stage in the game, Special Agent Garcia (who I imagine as looking like a cross between James Bond and Inigo Montoya) is killing an enemy spy roughly every 3 turns. The Russians, the Inca, the Aztecs, the Mongols, the French, the Dutch - practically everybody's sending their spies to Madrid to be slaughtered by Garcia. I just forgive them every time they come up looking so downcast about it. I don't even bother to tell them to stop spying on me anymore.

Versaguy said:

On high difficulty level you often need to play the catch-up game, the AI often obtain the first spy earlier than you, during this time it's easier to steal tech. There is no method to prevent it unless your tech is way too slow in which case there is no point stealing from you.

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No, I think that everybody obtains their first spy when the first Civilization in the game reaches the Ren area. After that, you gain your next spies by your own era advancement (starting with Industrial).

The time to steal a tech is calculated like this:

t = (c*m) / b

t - turns to steal
c - 125% of the cost of the most expensive tech that you can steal, at the turn when your spy starts stealing
b - beakers per turn of the target city, at the turn your spy starts stealing
m - multipliers... constabulary, police station, autocracy policy that doubles steal rate. The exact way the multipliers work (additive or multiplicative) doesn't matter for the original question, and I can't say for certain anyway

Note that both "c" and "b" are NOT updated as time goes by, they are determined on the turn the spy starts stealing.

So, the most likely answer to the original question is that you probably did not have expensive techs that the AI could steal (or maybe they didn't have the prerequisites for those expensive techs), while the AI did have expensive techs that you could steal, driving up the value of "c".

Of course, "b" could've played a role too. It is not at all uncommon for the AI to build the national college somewhere other than their capital. You should check when the spy arrives. They also like focusing production 100% when building wonders, no joke, they will have unemployed citizens for +1 hammer instead of working an amazing tile if it doesn't have any hammers. Sometimes, depending on how long it would take to steal, it's worth it to move the spy out and back in after they finish their wonder if there aren't any other good cities. Especially if the AI in question has the NC, observatory, and rationalism policy that gives +2 science per specialist. When they finish their wonder, the specialists go back to work, and science rate can easily double.



Another important point to make is that you don't always want to steal from the runner up in tech. If for example he has some expensive tech that you can steal from the top of the tree, but you would rather steal chemistry or fertilizer, it might be a good idea to steal from someone that's a bit further behind and doesn't have that tech that you don't want that's driving up "c". It's incredibly situational, but still worth knowing.

its all about the percentage of the empire's science output in that city. So, the best possible stealing target would be a player with only 1 city. Basically, the best target is the tallest capital in relation to the size of their other cities (and is ahead of you in tech).

Amask said:

Note that both "c" and "b" are NOT updated as time goes by, they are determined on the turn the spy starts stealing.

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Thanks, those are all terrific details. I sometimes shop spies around, looking for reasonable number of turns, sometimes ending back on the same city -- with the number of turns drastically reduced. This explains what was going on, and know that I know, I can be more systematic.

Trackmaster said:

No, I think that everybody obtains their first spy when the first Civilization in the game reaches the Ren area. After that, you gain your next spies by your own era advancement (starting with Industrial).

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Yeap. I was under the impression that the AI get the first spy earlier due to tech, but after this thread I read on espionage abit and realize that wasn't the case.

If a civilization reaches banking which unlocks the constabulary then a civilization could also be in the renaissance era. Banking could be a medieval technology btw.

Convict said:

Joncnunn, I tend to disagree with the AI rarely going for secondary cities. I have frequently had technologies taken from 2nd and 3 rd cities- especially if I have a killed a number of spies in my vapital. I would add that I prefer to pay wide.

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I'm like Joncnunn, I don't believe I've ever had a tech stolen from a non-capital. This might be due to my capital always having the highest science production. Generally be a very large margin.

I'm currently playing a game as Spain, immediately found Lake Victoria near my capital, settled Barcelona right next to it and built the National College and observatory there. I planted my spy in Madrid assuming the AI would target the capital despite Barcelona's better science production but Sweden stole a tech while spying in Barcelona. Obviously this is a completely overpowered site for Barcelona (did I mention I built Petra there with a number of farmed desert hills?) but it goes to show that spies do steal from non-capitals.