Quote Originally Posted by RedDevil
I noticed that all spies have 100% to sneak into the city or castle...
It is little stupid because i always can enter into the city or castle without siege weapon! Only thing that i need to do is to throw in couple of spies...
I guess that depends on when in the game you are. If you have a thieves guild up and running, you may be generating spies that have 100% success I suppose (still somewhat unlikely). Success chances in general should not be as high as you are noting, though. It's likely you modded your game, are not playing 1.2, or have a botched 1.2 install in which some files did not update, causing 1.1 behavior to stick around. In the early part of the game at least, infiltrating a settlement is usually more like a 50% proposition, if even that good. Basically if you are running a working copy of 1.2, spies should be much more difficult to use, and decidedly NOT totally easy to train. On the contrary, they have a propensity for dying on the job now, about on par with assassins.

As to the other various questions about 100% chances still having failures, I think it's a display error. In general the maximum displayed value is supposed to be 95%, and the minimum 5%. So at best you will still have a 1 in 20 chance of failing a mission. Even if the game indicates 100%, I would regard that as incorrect and assume your spy will still have that base 5% chance of failure.

Also, spies "leaving" a settlement is in fact due to them being found out and fleeing, escaping with their lives. You can sometimes spot this happening to enemy spies in your cities too, which is how I figured out what was going on: the enemy spy is thrown out of your city when you get the pop-up message about an enemy spy being uncovered but escaping the guards.

It also seems worth noting that it is not necessary in all cases to infiltrate a city or stack just to see what is going on in it. Usually you can spot the details of things just by having them in the spy's field of vision, which can help keep them useful, but more importantly alive. That way you can see all the things you want to, but save your spy for use on easier targets where he stands a better chance of success and thus survival. It really pays to be more selective now about what targets you send your spies on missions against.