Does it help keep enemy spys from completing missions by posting spys in you're own cities?

Yes. Then when you build Security Bureaus move the spies out of your cities onto critical resiurces like oil, or up to your borders

Does it help to have more than one? Or does the effect not stack? What percentage does it add to the opposing players cost of spy activity?

Also with putting them on the borders. How many spaces to you leave between spys?

Does it help to have more than one? Or does the effect not stack? What percentage does it add to the opposing players cost of spy activity?

Also with putting them on the borders. How many spaces to you leave between spys?

You don't need more than 1 in a city/tile. The effects don't stack.

I don't think Spies affect spy mission costs, just the success ratio.
Use a spy to run Counterespionage missions against the AIs that are using Spies against you. These will increase the cost of enemy spy missions.

If you have enough Spies, put them on every border tile.

1 spy per city is the best defense you can have.
1 security bureau is the best defense you can have.

2 spies in a city or 1 spy plus 1 security bureau is no better then either of the two above... you only need ONE spy or ONE bureau per city... "stacking" spies and/or bureaus gives you no added benefit.

If you have enough Spies, put them on every border tile.

You seem to imply that a spy will catch an enemy spy if it travels through the tile that your spy is in (and not: rests in that tile). Can anyone confirm this?

Hello!

In fact, not specific to tiles enemy spies are on, but on every move a spy unit makes through hostile terrain there's a certain probability that it is catched.

The calculation for that probability considers the following factors:
- The ratio of espionage points of the spy unit's owner versus the owner of the plot the spy is on.
- If a counter-espionage was performed against the plot owner recently.
- If spies of the same team are on the plot, and if not, if the spy is only there for one turn
- If an enemy spy (or if in a city, buildings with counter-espionage ability) is present

Regards,
Fabian Aichele

You seem to imply that a spy will catch an enemy spy if it travels through the tile that your spy is in (and not: rests in that tile). Can anyone confirm this?

You seem to imply that a spy will catch an enemy spy if it travels through the tile that your spy is in (and not: rests in that tile). Can anyone confirm this?

I believe they will slightly increase the chances of Enemy Spies being caught, but there is no way to guarantee you will capture their spies (unless you play with the new No Espionage custom game option). ;)

Super49er, this really works!! In my last game, I was messing around with ridiculous culture, and hardly any military or espionage. I was only getting 14 EP/turn in the 1700's!! So I tried your strategy of putting spies in my cities.. and WOW enemy spies were getting busted all over my territory:)

spies actually have a sort of "BFC" of their own... operating near an enemy spy (not in the same square) is more dangerous then operating in a tile with no spies anywhere near. Putting 10 spies in a 10-square tile radius is no safer then using 5-spies in the same area. Using more spies only ensures an overlapping of "covered" territory, but spies don't "stack" their protective bonuses. Your territory is either covered by a spy/bureau or it isn't. There's no bonus for saturation.

spies actually have a sort of "BFC" of their own... operating near an enemy spy (not in the same square) is more dangerous then operating in a tile with no spies anywhere near. Putting 10 spies in a 10-square tile radius is no safer then using 5-spies in the same area. Using more spies only ensures an overlapping of "covered" territory, but spies don't "stack" their protective bonuses. Your territory is either covered by a spy/bureau or it isn't. There's no bonus for saturation.

Very true. In fact it's a hindrance to have too many Spies. Use surplus Spies (From cities that have built the Security Bureau) to perform your own spy missions.

Of course you can pile more EP points towards the offenders.

Good to know about the Security Bureau and spy BFC's.

The point of border tiles is enemies usually come that way.

Why are spy nationalities sometimes revealed and sometimes not?

Hello!

If a spy's identity is revealed is decided by a separate test (based on a random probability), after a failed mission or if it is revealed while on a foreign map plot.

Regards,
Fabian Aichele


Why are spy nationalities sometimes revealed and sometimes not?

Very true. In fact it's a hindrance to have too many Spies. Use surplus Spies (From cities that have built the Security Bureau) to perform your own spy missions.

Are you saying that having too many spys in an area makes them less effective in catching enemy spies? That doesn't seem to make much sense.

Are you saying that having too many spys in an area makes them less effective in catching enemy spies? That doesn't seem to make much sense.
No, he's saying that having too many spies in an area doesn't help anything over having one spy in an area... so why have two or three or four covering a city when ONE does just as well? If you've got one covering an area, you get no added benefit for having more then one... so use any surplus for different missions.

Been having my first major play around with spies today. I have left very few spies in my cities unless they return from a mission.

I seem to be intercepting a high volume of AI spies. To be fair i have dumped a great spies in three in 3 different AI civs. In a few turns of doing this i was able to steal three techs off the AI without much trouble. i have over 4k in espionage points with the koreans so i should get a fourth tech soon

Goes to show its worth building spies. Its an aspect of the game i need to work more on. Didnt actually play for the great spies but not complaining.

Goes to show its worth building spies. Its an aspect of the game i need to work more on. Didnt actually play for the great spies but not complaining.
Having a surplus of Great Spies is a huge difference from having a game with no Great Spies. If you have to rely on normal means of espionage point production, the odds of ever stealing techs from an opponent are slim to nil.

i think that spies nationalities are revealed when they are found by ur securities bureaus or something.......
because i rarely ever build spies and usually it just say they stumbled upon them... but once i started investing in spies and security bureaus it started telling me that they were from certains countries and what not.

double post.
my bad.

The best way to counter spies is to DoW and kill the enemy off, once I had peter my neighbour, I blocked every border tile, every city had all espionage buildings, every key resource had spy on it but it didn't help, ofcourse I did counterespionage.