Hello everyone! I was thinking about going further in the universe and making it more complex and dense. And as I can imagine it, we can also go deeper into the very very dark side of things.

Here's my terrible idea: and why not to make slaves as any other good in the marketplace?

That does not imply that everyone can capture slaves, but civilization can have the choice they use/not use them. Here's some ideas how to implement that. Maybe some are to throw, but I believe in the G2G community to extend the list to make a cool stuff! The most difficult should be to balance the mechanism.

• Belonging to one of the sides, pro/cons slavery, can be a new way to  influence ideology (maybe linked with this idea  https://www.games2gether.com/endless-space-2/ideas/21-new-ways-to-influence-ideology).
  • So if you use slaves, you may belong to the slavery cartel, so you might have a small bonus belonging to other slaves civilization. Each actions  (makes more salves, steal slaves,trading,..) drives you to this side.
  • If you don't use slaves, you more likely to belong to the other side, so  you might have a small bonus belonging to other non slaves  civilization. Each actions (free slaves, not use them, ..) drives you to this side. Free slaves from a minor/major faction should provides a bigger diplomacy bonnus with.
  • To avoid a Manichean mechanism pro/cons, a middle way, the "opportunistic" one (as the Lumeris are) should be built with his own bonus/malus. Have to think more about it.
• When you buy slaves, the convoy has to physically go to the seller to the buyer stellar system: it gives the opportunity for some faction to capture the convoy, for its own use, or to free them.
• Have too many slaves (except for cravers or "slaves driver" factions) can lead to a revolt. Could be tuned with the ideology and repercussion on happiness, like pacifist really refuses it, a negative influence on ecologists, small negative influence on scientist and small positive influence on industrialist, while it has a positive influence on religious and military are approving it.
• Can be the a diplomatic way for "slave driver" factions to increase,  temporary, the relationships with other slave trading civilization.
• You can tune the behavior to yours slaves: are you despotic, or allow some of them to rise and become free, with different bonus it provides (may influence your position between pro slave/opportunistic, and also provides a different rate of BINS/unhappiness).
• It can provides more diplomatic interactions, as factions can ask you to choose your position pro/cons/opportunistic.
• We probably can add a lot of quest about slaves

And why not

• Makes sacrifice of a slave population to finish a building/ship? That's terrible, sorry for that, we should think about big malus with non slaves factions if you use this option.

Once again, it's just a game feature: don't be evil!