One concern I have with the proposed slavery system is historical consistency. While most of the civilizations in 0 A.D. practised some form of slavery, the way slaves were used varied considerably from one civilization to another. For example, the Britons did not necessarily have the same system of slavery as the Romans or the Mauryas. From what I’ve started reading (I’m by no means an expert on the subject), slaves seem to have been used extensively in agriculture in many of these societies, rather than for mining stone or gold or gathering wood. Perhaps agricultural bonuses would make more historical sense for some civilizations, while others could have different bonuses depending on their historical practices. I also think we should consider how different civilizations acquired slaves, since capture in warfare, slave markets and other forms of enslavement did not play the same role everywhere. I think some historical research would be necessary before settling on a single system for all civilizations. It could help us find a balance between historical accuracy and gameplay without making the mechanics unnecessarily complicated.

Hey, just wanted to introduce myself. My name is Sam but I go by Heliozah. I've been playing the game for roughly a week now and I'm loving it so far. It reminds me of when my dad and I played Stronghold. I'm more of a city builder game lover so I mostly focus on building up my city more than I focus on the war aspect, but I do enjoy that as well.. Just not when I first started and I was almost immediately attacked by the AI and barely survived... Just to have them come back and destroy everything again after I rebuilt everything lol I play as the Romans because come on... we all know they're the best! Anyways, I'd love to know any tips or tricks y'all have and just to get to know everyone playing.

See Delenda Est for the simplest way possible to implement a slavery system. One complexity I'd like to add is to make the available slave pool be a global limit rather than per player. But that's about as much complexity as I'd add. 

Google "The Oxford Handbook of Palmyra pdf", first link (dokumen.pub). Chapter 12 start at page 179 (198 of the pdf).

Local_Auxiliary_Units_in_Roman_Syria_Ico.pdf I found another strong one through Researchgate.