@Gazebo I will also add one additional comment that I've started a whole thread upon some time ago. In my opinion primary role of espionage is VISIBILITY. You send spies to understand what your opponent is doing (in real life, let say). To achieve this, I think, it would be great to have added a certain visibility radius to a spy depending on his level. So let say the lowest level spy put in the city sees only whats going inside of the city. The highest maybe reveals 3 tiles radius of the city, you just have a vision there, just like in your own territory. This way if you are planning a war and are unsure about the potential of your opponent, you can actually plan your invasion intelligently - you send your best spies to the border cities and gather a meaningful picture of whats going on - how many units are there, if they engage someone else maybe etc. Maybe if you send them to the cities of your vassal, you get twice of that radius? I dont know about the mechanics, but maybe if it feels overpowered, this can be turned into a seperate spy activity of sorts? so its either steals/disrupts or provides that "visibility"?