Total War: Three Kingdoms - How To Recruit And Assign Spies
In Total War: Three Kingdoms, you can use spies to sow discord between different factions. You will get access to spies when you hit the rank of Second Marquis, allowing you to use the Spy Network to learn information about your enemies and use it against them.
The Masterful Disguise Techniques reform will also give you access to a Spy slot for your Spy Network. If you open your character list, you can see any character that is willing to spy for you, as they will be denoted by a small eye symbol beside their role, just below their name.
How To Recruit And Assign Spies
To open up the Underground Network menu, hit the fourth symbol beside your portrait in the top left corner of the screen, or by hitting the number 5 button on your keyboard.
The first thing you will see is a circle with a plus symbol in it, under the words Active Spies. Hit the plus symbol, and a menu will open that allows you to pick your spy, and then pick the faction you want them to spy on.
To select a spy, you can either choose someone who is already in your Court or recruit someone specifically for the task. It is often better to recruit somebody, as many Court members can prove valuable in other roles, and risking them on a spy mission might not be the best use of their abilities.
After you have selected your spy, select the faction you wish them to infiltrate. If a spy is discovered, it will have a negative effect on your relationship with that faction, so it is best to send spies against factions that already dislike you. The hit to your diplomacy with them won't matter as much, and they are more likely to go to war with you anyway, so trying to get an advantage over them is not a bad idea.
Your diplomatic standing with a faction is denoted by the color-coded icons beside the faction name. The further from green and the closer to red, the icon is, the worse your relationship with that faction is.
It will take some time for your spy to infiltrate the enemy court, but once they do, you will be able to manipulate the target faction.
If you are having difficulty getting a spy embedded with a certain faction, it can be a good idea to speed up the process by starting a war with them and killing some of their characters. This will leave openings in their Court that your spy can then seek to fill.