Espionage, much like diplomacy, feels completely underdeveloped in 4X games and almost non-existent in strategy games overall.
Unlike other areas, spying plays a tertiary (at best) role, like a feature that was tacked on late in the development just for the sake of it. It doesn't connect well with other systems, we could cut it out and the changes wouldn't be even noticeable. Its design doesn't help either – limited in scope and use, with simplistic mechanics that doesn't allow for any player input.
We intend to create an espionage system that feels like an integral part of the game, is useful and sophisticated without being a micromanagement nightmare. It’s easy to criticize, but how are going to tackle these problems ourselves?
Spies aren't cannon fodder you can send out in thousands. Not unlike heroes, each spy has a name, a portrait and stats. You can train them yourself (the cheaper but less effective option – unless you are playing an espionage-heavy race) or hire them on the galactic market (these are costly, but more skilled).
Agents can be assigned to different positions. For now, we will definitely implement counter-espionage, a defensive measure against enemy spies, and three exterior missions: theft (acquiring designs), infiltration (learning another empire’s intentions) and intel (keeping track of enemy fleets and colonies). Every assignment will contribute a specific amount of mission points each turn. This is calculated by appropriate skills of the spies taking part in the mission versus enemy counter-espionage. You will be also informed how many points were scored against you (though you won’t know what or to whom are you conceding exactly), so you can reallocate your spies. Having continuous progress of missions rather than one-off actions with a % of success makes it more fluid and discourages save-scumming. So if you are stealing technology from race A, the progress will look like this:
Turn 1, 1 spy active: +5: Total 5
Turn 2: 1 spy active +5: Total 10
Turn 3 1 spy active: +3: Total 13
Turn 4 1 spy active: 0: Total 13
Turn 5 2 spies active: +10: Total 23 acquired
Spies can also be caught. There will be a counter going on for every spy on a mission. When it reaches 100%, the agent is caught. You will see a text assessment of the risk (“hidden”, “unsafe”, “in danger”), but not the counter itself. Uncovering a spy means a big hit to relations and a casus belli. The agent himself can be either executed or ransomed.
The larger the empire, the harder it is to prevent enemy spies from infiltrating it and the more agents you have to assign to defence. Maximum number of spies you can hire is limited by your population, so a small but developed civilization can bolster a powerful intelligence network, while a sprawling, spread out one will have problems counteracting opponents’ actions.