Cost of passive espionage missions

Can anyone tell me how the game determines how many EPs are required for passive espionage, more specifically how those costs increase? It's my understanding that the more EPs the AI spends, the higher the cost of, say, city viz or investigate city. If I'm outspending him, I'll gradually catch up to that point. For instance, say I need to see what WK is building in Seoul and Pusan, so I look on the espionage screen and see I need 1000 EPs for Seoul and 1100 for Pusan. I have 950 against him, he's got maybe 600 against me, and I'm outspending him 20-10 every turn. Assuming neither one of us changes our EPs against the other, I would guesstimate I need about 4 turns to investigate Seoul (I'll be at 1000 in three turns, but by then his EPs will have increased and the mission might cost 1020 instead of 1000). Y'all with me so far?

So. How come there's random jumps in the cost of missions, instead of the gradual increase I would expect? If he suddenly ran 50 EPs/turn against me, that would make sense, but he's not doing that. If he popped a GSpy and used him in one of my cities, I'd be able to see the +9000 or whatever it is (Marathon) that turn, plus his total EPs against me would show that.

Could it be counterespionage? I alays thought that only affected the costs of active missions, not passive- plus the required amount only seems to be jumping in certain cities. Like, maybe the investigate cost jumped 200 points in Seoul, but is still slowly increasing in all his other cities.

Any wisdom on this? I don't wanna be the "hurr durr computer cheats" guy, but the way it keeps spiking whenever I think I'm close is getting kinda irritating.

EDIT: I looked for guides/articles- I found some good info about espionage but I didn't see anything about this particular issue. If there's one out there, please let me know...

As a wild guess in the darkness...

Spy in the city in question, either as a specialist or as a spy unit stationed/passing through.

I have no idea how those things apply, but I do see the 'keep some spies in your territory for counter espionage' tip and assume if the programmers are giving me a tip they probably have the AI following it.

Hmm, that could be it. "Defensive spies" was another thing that I always thought was strictly for protection from active missions, but maybe they interfere with passive ones too. That would also explain away the quasi-randomness.

Maybe could check with WBuilder... put AI spy in that city and check Espionage info again (or next turn because calculations might not work right way)...

Good idea- I checked, and once I got him to actually leave the spies where I WB'd them, they don't increase the cost.

pondering next idea

Any way to convince them to have a spy specialist in city with WB? Maybe make a city with a courthouse, plenty of food, and no other specialist options...

Did he just complete a Security Bureau?

Security Bureau or a resident spy in the city do not increase cost. Instead they decrease the probability of a successful mission, and increase the odds that the spy you send will get caught. Counter espionage missions do increase the cost. Perhaps your target AI ran a counter espionage mission against you before your spy got there.

As to the projected cost increase rate, I don't know the mechanism but since everything else in CIV seems to increment in steps (culture level, XP level, inflation rate, etc), I would suspect that the espionage costs do the same thing. So instead of a steady increase in cost, there are sudden stepped increases as the number of EPs the target has against you increase.

s.bernbaum said:

Security Bureau or a resident spy in the city do not increase cost. Instead they decrease the probability of a successful mission, and increase the odds that the spy you send will get caught. Counter espionage missions do increase the cost. Perhaps your target AI ran a counter espionage mission against you before your spy got there.

Click to expand...

I am now a little bit wiser, I misunderstood the workings of that building. It sounds like counter espionage would explain what the OP was describing.

IIRC counterespionage trebles the cost of espionage missions, both active and passive. An increase of such a huge amount would be obvious!

Passive missions are also modified by things like the shared religion and trade route modifiers which can change.
I suspect that the base costs of passive missions would be dependant on easily changeable, and generally increasing things like the population of the city, perhaps of the civ as a whole so those would be a much more likely cause of the OPs question..

Espionage missions cost espionage points but if you leave a spy in the other civilization's city for a couple of turns. .. you could reduce costs of different espionage missions and increase the probability of success.

Sorry to open a thread and then disappear for a week and a half, a whole bunch of life happened.

Timsup2nothin said:

Any way to convince them to have a spy specialist in city with WB? Maybe make a city with a courthouse, plenty of food, and no other specialist options...

Click to expand...

Hmm. I put a spy unit there, didn't think to try and force spy specialists. Might try that when I get back to my game.

Mec AntiKythera said:

Did he just complete a Security Bureau?

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Good idea, but none of us are that far in tech yet. (We are now, but not when I posted the question.)

s.bernbaum said:

Security Bureau or a resident spy in the city do not increase cost. Instead they decrease the probability of a successful mission, and increase the odds that the spy you send will get caught. Counter espionage missions do increase the cost. Perhaps your target AI ran a counter espionage mission against you before your spy got there.

Click to expand...

It's not an active mission, I didn't send a spy. (Also directed at reddishrecue.)

As to the projected cost increase rate, I don't know the mechanism but since everything else in CIV seems to increment in steps (culture level, XP level, inflation rate, etc), I would suspect that the espionage costs do the same thing. So instead of a steady increase in cost, there are sudden stepped increases as the number of EPs the target has against you increase.

Click to expand...

Hmm... that makes sense.

Ghpstage said:

IIRC counterespionage trebles the cost of espionage missions, both active and passive. An increase of such a huge amount would be obvious!

Passive missions are also modified by things like the shared religion and trade route modifiers which can change.
I suspect that the base costs of passive missions would be dependant on easily changeable, and generally increasing things like the population of the city, perhaps of the civ as a whole so those would be a much more likely cause of the OPs question..

Click to expand...

More things that make sense.

Good ideas all around, thanks. It's just kinda frustrating to start getting more into micro but finding something that I don't grok...

s.bernbaum said:

Security Bureau or a resident spy in the city do not increase cost. Instead they decrease the probability of a successful mission, and increase the odds that the spy you send will get caught. Counter espionage missions do increase the cost. Perhaps your target AI ran a counter espionage mission against you before your spy got there.

Click to expand...

I would like to clarify that the security bureau does increase the mission costs. Take a look at the following screenshot taken by my recent Saladin game:

Spy Mission of Sabotaging a Granary at Shushan


Spy Mission of Sabotaging a Granary at Dur-Kurigalzu


As we can see, we get an additional City Espionage Defense cost at Dur-Kurigalzu. Also the chance of success is decreased by a certain percentage (-16% in this example). So we can conclude that the security bureau does decrease the chance of success of enemy spy missions and at the same time increase the enemy espionage costs. A powerful building indeed!

pandamancer said:

As we can see, we get an additional City Espionage Defense cost at Dur-Kurigalzu. Also the chance of success is decreased by a certain percentage (-16% in this example). So we can conclude that the security bureau does decrease the chance of success of enemy spy missions and at the same time increase the enemy espionage costs. A powerful building indeed!

Click to expand...

The Security Bureau acts the same as a spy for espionage defense. But the "sabotage building" is an active mission, and TheMulattoMaker was asking about increases in costs for passive missions.

When not comparing within the same city, you also are varying many other thing. Distance from capital, religions present, trade routes, etc.

Lennier said:

The Security Bureau acts the same as a spy for espionage defense. But the "sabotage building" is an active mission, and TheMulattoMaker was asking about increases in costs for passive missions.

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Yes, you are somehow correct. However, Security Bureau also increases passive mission costs. Take a look at another screenshot taken by the same Saladin game (See city visibility and investigate city):

Passive Espionage Costs in Dur-Kurigalzu with Security Bureau


Passive Espionage Costs in Dur-Kurigalzu without Security Bureau (Go to the world builder, removed the security bureau)


To rephrase again, security bureau does decrease the chance of success of enemy spy missions and at the same time increase the enemy active and passive espionage costs.

I hope that clarifies everything.

traius said:

When not comparing within the same city, you also are varying many other thing. Distance from capital, religions present, trade routes, etc.

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I think you misunderstood me, my previous post is just to show how the security bureau affects espionage (ignoring other factors). I used the example of two cities to display that the +50% city espionage defense is due to the effects of the building and not due to counterespionage, which if that is the cause, should be applied to all Babylonian cities (I think).