Hey,
playing RI I've come across some more cool features that might be good for DoC
- allowing for 5%steps on the research/culture/spy-sliders, not really important but quite nice to have, I usually try to run a sustainable research rate despite the fact that 0/100% is supposed to be better, so these smaller steps allow you to get to that equilibrium state between research and money a bit better
- civic choices unlock/lock buildings. This in combination with the next point allows RI to get the player to want to move through several civics over time and especially away from slavery at some point.
- let buildings&techs improve tile production (like the Dutch dike, printing press and a few others already do) , for example a market could give +1 commerce to villages/towns-tiles within the city radius (bad example in terms of balancing just to illustrate the idea)
For example early slave plantations could have some production/commerce boni (as they currently have) but then tech advances could enhance normal plantations while the slave ones remain at their old value.
- whipping could gradually become less effective maybe something like some techs reduce the amount of hammers gained per citizen whipped (also please display "hidden" factors like researchinh Nationalism giving you a negative stability modifier for running mercenaries in the techs info-pop-up (can provide pics later if anything is unclear)