Countering Spies

[Charles 22]

Does placing the number of spies in each city stop as many spies as try to get in to steal something? I thought of that out of the clear blue, after playing CIV3 for quite a long time, as spies were one of the things about CIV2 that I couldn't stand. Is there something else I can do if that don't work?

 

[Stegyre]

My own strategy is to place 3 vet spies in each of my cities, which stops virtually all attempts at theft. (I usually have a very small number of cities, so this is do-able as long as I am not on an end-game conquering rampage, when it typically won't matter what techs the AI steals: it's too late for them.) Even one vet spy should substantially reduce the AI's chance of success.

Barring that, you have to stop them from ever reaching your cities, which is a bit of a pain: it takes many more units to wall-off a city than the 3 spies I would place inside.

 

[Duke of Marlbrough]

http://forums.civfanatics.com/showthread.php?s=&threadid=80476

A diplomat inside the city has a 20% chance to foil the attempt.
This grows to 40% with a spy and 60% with a vet spy.
It is also cumulative:
For example, with 2 vet spies inside the city, your chance to steal the tech is reduced to 0.4*0.4 = 0.16

The easiset way to stop spies is to be in Democracy.

 

[Charles 22]

Thanks guys. I tried a diplomat fortified in a city and it did no good. It's nice to know that blocking off the city entirely or using democracy will work too. I guess walling it off with units is best, then you probably don't have to worry too much about what anti-spy defense is in the city.

 

[Specialist290]

Be sure the units are stacked, though; a single unit can be bribed (unless you're in Demo). Watch your coastlines, too, since they can also sneak in directly from ships.

 

[Charles 22]

Be sure the units are stacked, though; a single unit can be bribed (unless you're in Demo). Watch your coastlines, too, since they can also sneak in directly from ships.

Stacked? Are you talking about having multiple spies in the same city hex as stacking? As far as coastlines go, CIV2 is so replete with coasts that if you haven't been hit that way numerous times in the same game you must be asleep. That does bring up the point that a city largely broderedby coean serves, sometimes, as easier protection. The difficult bit is usually when the AI just has the trineme (sp) and he sends those every once in a while. If you can get a sturdier ship you sure are safe for a pretty good stretch.

I only used one diplomat in that city because I didn't have very many, and didn't want very many for just defensive purposes, because I was hoping that putting one in every city would make them immune. Apparently when being alone, the dips. will only stop 20% of the attacks.

 

[ElephantU]

Stacking refers to having more than one unit on the same non-city land tile. Stacked units are "supposedly" immune to bribery. I put that in quotes because rare cases have been reported of the AI bribing a stack. There may be a "desperation" percentage test, like 1/100 if the human is 2 power levels greater, or something like that. Multiple spies in the same city has already been mentioned - their disruptive power is multiplied together, but they do not rule out tech theft completely.

As in most things, the best defense is a steamroller offense...

 

[Hexer]

"a single unit can be bribed (unless you're in Demo)"

Unless you play at deity-level .
The AI is able to bribe a Democracy-Unit at deity...

 

[Stegyre]

The AI is able to bribe a Democracy-Unit at deity...

Do you have an example of this happening? I play only at deity level or higher, and have never seen a democratic unit bribed.

 

[Ace]

I don't have an example, but I have seen it happen. Admittedly, It is a very rare occurrance, but it does happen. Only to units, not cities. IIRC, there are some old, maybe 02 or 03, threads regarding this. Maybe one of the Mods, with access, can search for them?

 

[Charles 22]

Since I got the advice that one vet spy is worth 40% of rejecting spy attempts on the residing city (well at least the 1st two are 80% rejection total), I've been playing the game. One city in particular, front line of course, has the AI attacking it with spies a good number of times since I started this thread. The end result, though rough, is that "maybe" one time the enemy has been rejected. I mean I'm placing 4 or more spies in that city and the AI is getting through that at least 90% of the time, so I dispute that the advice was any good (CIV2 2.42 here).

Conversely I have been attacking the AI too with spies. I estimate that only about 80% of my vet spies are getting through (I'm using nothing but vet spies for defense and attack), despite the fact that usually the cities I'm attacking have no spy units (or diplomats) in them. I'm having the spy select the sabotage themself and indeed the AI is being confined to sabotage seeing as how there is nothing left to steal anymore.

It's real sweet to have no way to reject the spies on a front line city and they keep destroying either the SDI or anti-air missile defense. The enemy attacks in that place so regularly that putting any units in front of the city to try to wall it off is quite problematic. Just today I figured out a way to allow my engineers how to make any improvements on the front with very mobile units of the enemy against them. It just seems to be a lot more hassle than it's worth. And to think I will have to keep doing that with whatever the city flavor of the year happens to draw the AI's interest.

I'm playing beyond 2020 BTW. I'm playing at this point to wipe out the map with 2 enemies at present and no alliances. But this protecting your SDI and missle defense by means of making large fortifications with large amounts of units will get quite ridiculous.

It's also funny how frequently successful the AI is at taking out my SDI and missile defense, when I imagine that letting the spy make the choice for sabotage works better. I've tried selecting SDI against the AI for example and both times the spy acts like it can't be done, so how does the AI get away with it so easy? And it's not like his city has more military, therefore perhaps a better guard for the SDI than I do. He has maybe 6 units tops most of the time I check the city beforehand, whereas I have usually 12 ground units and maybe 5 air units.

 

[TimTheEnchanter]

On the democracy bribes...the AI has also been known to bribe your troops with military (not diplomatic) units. Again, it's rare and I haven't seen it in some time (maybe it's an MGE thing, since I play that less now) but I have definitely seen it happen.

As for defending against spy attacks, how well connected are your civs. if there is not a good road/RR network between your civ and theirs, you could put a fort with 2 units to block the path so it can't reach your city. Personally I'd be inclined to just ramp up to exact some retribution from the other civ until they've learned their lesson.

 

[Charles 22]

At one time there were good rail links and such, but I went out and severed them via pillage. Funny how I hadn't thought of severing them further and then monitoring them. I suppose because severing the rails slowed the enemy assault enough to where it was bearable, which of course points out that I wasn't doing it for the sake of slowing down spies, that I forgot that doing more severing might be a good thing.

That's probably the best idea I've heard so far, to sever the links and then maintain the severing. I was thinking along the lines of forting all possible routes to the city, but the problem is that they're attacked so frequently that keeping them maintained would be a pain. It seems destroying enemy engineers by air is less of a hassle, once the sacrificed units go out and sever the lines real good.

Since I've wrote the last post I've had between 3-5 spy attacks against me, all getting through. That spies protecting the city idea sure was lame. I have dealt out a little retribution though. Part of my dilemma was that I could never knock out the SDI. The only hope seemed to be to hope my spies hit the AA missile system and then destroy the city occupants with air attack, and then occupy the city. Takes a bit long but not too bad. Well those last enemy spy attacks got me steamed, so I dared do something that I was holding back on, ta-da, the ol' spy nuclear device trick. First of all I never used it because I was afraid of a backlash, but seeing as how the game was getting ridiculous anyway, and how I had already used ICBM's how much more could I get in trouble if I planted spy nukes? I also thought they had a very high rate of failure. Well so far that's not true. Two cities got plants, two cities nuked, and now mine. Well at least I'm up 2-0 in the spy nukes category. It's so nice to still have the SDI system up on those cities you conquer that way!

 

[Prof. Garfield]

Just so you know, spies stationed in a city don't prevent sabatoge, only tech theft.

 

[Charles 22]

Yes, I was afraid of that, but the earlier quote said of it's chances to foil an attempt, only whether they spoke of stopping all spy activities against a city was in question. It does seem pretty dumb that once all the techs are discovered they're completely defensively useless.

 

[biru biru]

I believe that courthouses make cities more resistent to spies and diplomats.

I personally use a lot of doplos and spies in my games. The AI has never used as many as me (diety lvl, MGE), although I have noticed that the AI success rate is much better than mine. AI usually steals tech or incites revolt.

Move 3, ignore zones of control makes spies tough to keep out; for a land assualt, terrain can be terraformed to slow them down (a wall of trees will stop them) in combination with sabatoging rails (previously mentioned). Bombers can pretty easily scout for spies if you have the patience to do manual border surveilence every turn.

I had always assumed that spies fortifird in a city are effective against all diplo-attacks. Prof Garfield, Charles; how did you come to discover that only tech steals are slowed? (if I may...)

Last, I have had the problem of the AI bribing units with non-diplomatic units as well; I assumed just an unfortunate IA 'cheat'.

Anyway, I love spies. Probably my favorite unit in the game at diety level, honestly. The variety of tactical options that they offer the player, including fast tech catch-up, scouting and establishing embassies, escorting other units through enemy territory, taking out city walls or air defences, and even bribing or terrorism make them very powerful and relatively cheap. Arguably too powerful; but only arguably too powerful in the hands of a human player. The comparatively minor damage that the AI does with spies is harldy worth complaining about!

 

[Charles 22]

Yes, I forgot about the courthouses, but since I'm running communism for the most part I'm not too concerned about getting them. The earlier note about how effective spies are defensively, be it that Prof's conclusion is right or not, and their achieving almost zilch against what was mostly sabotage attempts, doesn't leave me too anxious over courthouse possibilities. If the AI fails more frequently, however, he may figure that it's not worth the expense and therefore a good strategy for me. Having said all of that I can definitely see how putting a courthouse in the 3 or 4 most susceptible cities would be a good idea.

This game, at least the random ones, is so coastal-based that keeping enemy AI out by means of terrain destruction isn't too practical, though isolated instances of using it would serve well to remember.

I guess one could always surround ports with ships, but seeing how an entire stack is lost quite easily that's pretty much hopeless.

BTW, today I put like three spies in one city waiting using them in offensive missions, and it looked like they didn't cost any upkeep despite the city being over the unit limit. Is this true, because I could've sworn I've seen them take upkeep (maybe communism makes them free of upkeep, whereas monarchy does not)?

I think Prof is right about the spies being able to stop only stealing of techs, because the sabotage going on like no spies were there, and, of course, if the AI is resorting to sabotage, especially frequently, that probable means there's nothing left for him to steal.

One thing that does gripe me a bit though, and maybe I just need to relatively ignore it, is that I get warnings when I try to steal techs from the same city, as though the spy is twice as likely to get caught, so I don't use them then. But I'm pretty sure the AI had no qualms about constantly stealing from the same city, and he failed only once, if that. He probably succeeded mostly when I was in monarchy, but he was getting by when I was in communism too.

BTW, guys, is there a way to destroy a city in this game? I suppose straving it to death might work but is there any other way?

(phew)

 

[ElephantU]

Dips and Spies don't require upkeep shields - the only other units you can build that don't require upkeep are caravans and freights.

If the city is not your first and only one, you can "disband" it by starvation (slow) or by building a Settler/Engineer when it is size 1. You get a "delay build or disband city" confirmation box the next turn. If the city IS your first and only, a Set/Eng is built without disturbing your Food Box. This is the Size1 Settler trick. Note that when you disband cities your other supported units need to have their support relocated BEFORE you disband (except Partisans, which become NONE automatically); the new Set/Eng will try to get support from the nearest city - if it is not yours it becomes a NONE. There have been several tricks developed that take advantage of these things.

 

[Charles 22]

Thank you very much. It's very good to know.

 

[la fayette]

Charles 22

SlowThinker and I tested thoroughly almost anything that can be achieved by diplomats and spies about 3 years ago.
You can find detailed results here:

http://home.tiscali.cz:8080/~cz045662/civ2/dipspy.htm

If you have done some testing giving different results, just post here.
I am fairly sure that SlowThinker is just as willing as I am to take your tests into account.