Guys, I seriously dont understand the idea behind espionage mechanics. Its probably me, who dont understand it, or its a flawed game design. First, training spies costs A LOT. Base cost is like a district (300 hammers on standart speed), then each next spy will cost even more, like +100 hammers per spy. You can lower building time by adopting a renaissance civic, but its still a very long process (10+ turns on standart speed in a high production city). And it seems that military city-state bonuses to build units and encampment bonuses to production doesnt help. Second, spies die and they die randomly and often. So, you train spy, invest A LOT, then you lose him on a 74% success mission. You are lucky if they capture your spy, at least you can offer some gold to get him back. But if they die, you need A LOT + 100 hammers to get a replacement. Third, spies offer mediocre benefits for you. You can risk and try to get some cash (180-300gold on standart speed), which is a really bad deal by the time you develop spies. And if you fail, you lose A LOT! You can risk even more and try to snatch some great work. But the chances are miserable and again, if you lose, its GGTHXBYE 300-500 hammers. Oh, and you can simply buy these great works with gold by trading. Fourth, there are so few options to enhance espionage actions. Yes, you can increase production rate by 50% (still 10+ turns on standart speed in a high production city). Yes, their missions can be faster (6 turns instead of 10? on standart speed). Yes, very late in the game you can also get some bonuses if you hunt eurekas. And you can invest some time to boost a spy so he can act as a spy 2 levels higher (what is it?), but then they still gonna die, no matter how much levels they got. And finally, AI will always know that you are spying on them. Which is really bad game design desicion as I see it. In Civ5 there was a rather high chance that AI wont know whos sending spies. But here, in Civ6 they always come to you, complain, and you get -influence with them. It seems that spies just come to town and say "hello, im a french spy!" to everyone... Ah, you can send spies on counterespionage mission. But you have to choose a city, then choose a district and then you still get a chance that enemy will still do damage. So if they move their spies, you have no control over where to guard your own cities. Guys, let me know if Im missing some important features or facts about current espionage system. At the moment its pretty raw and flawed in my opinion.