How to thwart spies on Prince level?

[Bestbank Tiger]

Just moved up to Prince and won my first attempt. But it required a lot of creativity--the Spanish had a larger empire and started stealing tech--at least 7 of them in a few turns--in order to catch up in the space race.

I saw what they were doing and put all my cities on the same wonder, so I could switch to Components and Modules when I discovered the last few techs I needed. I also sold off a lot of improvements to rush-buy parts, since I figured I'd need a 33-8-8-1-1-1 ship.

Anyway, how do I stop the spies? I outplayed the AI, but that one little thing kept them in it. Can 2 or 3 spies per city stop them? Do I need the entire city surrounded by units in forts?

Thanks.

 

[ElephantU]

Were they coming across terrain or jumping out of ships? Did you try physical blocks - lines of doubled units, like other spies or caravans? A line of ships can block a water strait too. A couple of spies in a city is supposed to cut down the "success rate" of steal attempts, but it seems like they always succeed eventually. Were you at peace or war? The best defense is a determined offense...

 

[Bestbank Tiger]

They were coming across land. I was at peace.

Wouldn't physical blocks cost a ton of shields? You'd pretty much have to occupy all 8 squares...and if you're not in Democracy they can incite a revolt.

 

[Ace]

You have Flight. Build a few fighters to patrol along your borders. A fighter can move 10 hexes, so just sweep in front of your cities and kill any spies trying to approach. If your have stealth, stealth fighters can move 14 hexes.
The only sure way to foil a spy is to kill it, before it can reach your cities.

 

[ElephantU]

"Killing" them during peace does not actually destroy them, it just sends them back to their nearest city to try again. If you have enough empty space between their city and yours you should be OK with fighter sweeps; if there is only a few tiles between you, you need to build a wall. I like using Dips/Spies or vans as there is no support and I always like to have some extras around anyway. Pick a choke point if possible and mix a couple military units in with them so you can "kill" those that try to sneak around.

 

[6K Man]

As I recall, AI Diplomats/Spies can automatically steal the necessary techs to build a spaceship in the late game. So stationing your own Spies in your cities is futile.

If at war, kill them. If at peace, block them off with rows of units (double stacked if not in Democracy).

 

[Ace]

Nope, the AI does not automatically get to steal "stuff". You can stop it. Sometimes, even your dips can frustrate an AI dip.

If an AI civ, like the Spanish in your game, steal more than 2-3 techs from you, you should declare war on them and wipe them out. At least, after you take several of their cities, they will be a lot more careful about stealing "stuff" from you. (And it feels so good to smash an AI civ after it does something nasty when your trying to be a nice guy).

 

[6K Man]

Nope, the AI does not automatically get to steal "stuff". You can stop it.

If the AI is trailing in the space race and Apollo has been built, the AI absolutely will automatically steal Space Flight, Plastics, and Superconductor. Thefts will stop being random - it will steal those three, regardless of the presence of Spies in the cities being stolen from.

 

[Ace]

The AI does not "automatically" steal techs, it must send in a dip or spy to do it, and spies do have the ability to choose which tech to steal....

 

[6K Man]

The AI does not "automatically" steal techs, it must send in a dip or spy to do it, and spies do have the ability to choose which tech to steal....

Absolutely, the AI needs a spy or diplo to conduct the theft. That's fairly obvious!

My point being that in the circumstances I described, the theft of one of those three specific techs is automatically successful, regardless of the odds, or the presence of your own spy or spies in the city being stolen from.

 

[Ace]

Have you tried having 3 fortified Vet spies in the city you want to protect?

 

[neutrino]

Too bad, Civ does not have built-in Geneva Convention. Spies, saboteurs, and ununiformed combatants can be arrested and shot on the spot.

 

[Ace]

Ahh, unless your allied with an AI civ, you can always "shoot" its spies. Of course, it may start a war, but....

 

[6K Man]

Have you tried having 3 fortified Vet spies in the city you want to protect?

Have you?

 

[Ace]

Yes, and it even works some of the time. But it is still better to wage war on the offending civ and cut it down to size. After all, a civ with only 1-5 cities is not going to beat you in a space race. (OCC human players excepted!)

Granted that most of the games where I reach the SS launch point, the AIs have been reduced to one city and present no threat, unless you consider a suicide attack the ruins your peace bonus a threat.