1. No, only 'production tiles' can be sabotaged.

2. Nope. Once it stops working, it stops working until they Nullify with a spy of their own (thus killing both spies).

3. Yes. You will get a little red dot in the lower right corner of the planet, showing that they have a spy there. Also, in your Empire->Espionage tab, there is a list of where your spies are and where any enemy spies on your planets are. It tells you the planet and then the name of the tile (eg Earth Factory). I don't remember off hand, but the IGN may give you a notice about it too.

4. The slider now spends more money on agents, rather than passively raising intelligence it gives you the ABILITY to get the intel. You can use 25% of your economy, I think, to train spies. They start out cheap, but then get more and more expensive the more you train. When you start, you obviously have to intelligence rating on other races. You put a spy on an enemy planet to mess things up. The longer he is there without getting nullified, the more points towards an intelligence level you will get with that race (with the bonus of that tile being deadweight). Your agents are always the same effectiveness and do not gain levels. I believe that is where the espionage stat point comes in handy. My guess is that helps your spy be undetected for a little while.

5. You have to train and wait. Currently I am going full bore on training, but I have trained so many due to a spying super event that they are take 20+ turns.

6. Nope. The spies are all vanilla. No specialties and no stats other than your main espionage stat.

Hope that helps.

Yes, and you get a drop-down notification on the side of the screen when one is planted. All you need to do to remove them is have a spy of your own available, go to the planet screen, and neutralize the sabateur.

hum... if I understand, the moment I put a spy on an enemy planet, he knows about it ? I though that spies could be undercover for a little while. In fact, it would have been nice to spy your own planet in order to detect an enemy spy instead of having it cover-broken the moment he starts to operate.

hum... if I understand, the moment I put a spy on an enemy planet, he knows about it ? I though that spies could be undercover for a little while.

He does not know who planted it, though, and unless he (or you, when the AI sabotages you) has spies waiting and ready, it's not always feasible to swat every one that appears, at least immediately.

Lets say for example you put an agent on an "invention matrix", what does it actually do and is the effect instantaneous? Will the research bonus stop intantaneously for that building or do we have to wait until the agent sabotages the building after awhile? Also, if I put my own agent to sniff out an enemy agent, does it happen as soon as I implant that agent or it takes turns?

The Invention Matrix would immediately cease producing research. If you nullify a saboteur, it is removed instantly (as well as the spare spy you used to do it).

I'm curious, is their a cap of how many agents you can have??

Only as many as you can afford, since the cost scales with your overall economy size (AFAIK) as well as rising with each additional spy you train.

Am I assuming correct if I say that we can only put an agent on enemy planets if we reach the right intelligence level to be able to "view" that planet's infrastructure and that we have the necessary range in order to transport that agent to that planet? I know that you place your agents automatically in enemy buildings, but what if the enemy planet is so far that even your ships can't reach it yet because you don't have enough sensor range, can you still put an agent so far on that planet?

You can see any planet at any time, as long as you are at peace with that civ. If you are at war, then a 'high' level is required in order to view a planet. Your level of intelligence on a civ depends on the amount of time that you have an active agent on that civ's planet. Range is not a factor. You can place an agent on any planet, regardless of range.

While on the subject of spies in DA...

Has anyone found an easy way to know what your current intelligence level against a target it? I always forget which race I've been able to keep a spy on the longest, how much intelligence I've collected and haven't found a setting for a simple way to know my level.

You no longer collect intelligence like you do in "vanilla" GC2. Instead you only gain intelligence on a race if you have a spy on their planet(s). Therefore there is a benefit from leaving a spy on someone's planet for a long period of time.

It gets mean when people start mass-targetting the same type of building. If you think your opponent is low on cash you can target their economic capitol and all their stock markets, for example, crippling their economy until they can remove thoes spies. Of course, not having an income makes it harder to hire more spies

I haven't payed attention to the spy cost yet, I just slide it as high as I can afford to.

Does spying eventually stop if everybody is spy swatting?

If a civ's economy is in trouble, it will no longer be able to afford to train spies, and so yes, it will stop. (for that particular civ) Any agents already trained/placed will still be available for use.

Just a few questions to see what I got wrong about the system:
If I always keep one agent at hand and go through all my planets each turn I'm basically invinceable against espionage until someone sends two spies at once?
Is it possible to recover from being struck by a few agents at your economic center? As far as I understand the victim gets fewer money, can effort less agents, gets more enemy agents, gets even less money, can effort even less agents, repeat.
This agent-chase sounds very boring and yet very lenghty. Can I make someone else do the espionage-tasks? I mean - I have to rule an empire. I hire the people who hire the people who hire the people who tell people to tell people to tell agents where to go.

No, when you use a spy to counter another player's spy, it destroys both yours and his.

As I understood it you train agents and keep them at stock until you use them. If I now take care to always have at least one agent at stock then I should be able to neutralize any enemy agent I get sent until someone sends two agents. That defensive agent is lost, but the enemy's agent is lost too, so were just exactly where we were before. Repeat until end of game.

Since spies get progressively more expensive to train, the enemy can't just keep sending an unlimited stream at you.

He doesn't need to shell out endless amounts. He just needs to be quicker than the victim, and the progressive-price mechanics apply for both in the same way. Just with the drawback that the victim has fewer money due to the sabotage and thus won't be able to keep up.

Plus the AIs will generally not gang up on you spy-wise unless you're already the most powerful civ in the game.

Why shouldn't they? Sounds like a good strategy to me. Spam one race with agents, cripple it economically, set up the devil's-cycle and that race is doomed. Repeat for next race. If I were the AI I'd do that.

Has anyone found an easy way to know what your current intelligence level against a target it?

Sorry, Malekish, just noticed this one. Yes, there is. In 'Foreign Relations', view the report on whichever race you are curious about. It will tell you in there.