I like what Imp. Knoedel is saying, especially regarding commerce versus gold. The important thing that V and VI are missing is personality, or identity, I think. Agendas were a nice way to bring this back, but they're built on an extremely flawed diplomacy system that fails at every single thing it could hope to accomplish, from friends/enemies to trading to UI to even showcasing the artwork that went into designing it all. Agendas should also be broad, and in that sense, they might resemble the (as in, easy to mod) <Flavor>, <UnitAIWeightModifiers>, and <ImprovementWeightModifiers> mechanics. A Viking leader could have the flavor 'gold' and favour the unit action 'pillage'. This leader could further respect leaders who pillage a lot. I do, however, believe that punishing players for doing well is a very bad idea; no agendas should be something like 'dislikes players who build a lot of wonders'. But an agenda could be 'desires to have a lot of wonders'. That differs from <iWonderConstructRand>, because if there are no wonders to construct, for one player has amassed all the wonders in his or her capital, then the leader with this agenda would be inclined to declare war (though, of course, there are far more factors that should go into this decision). That is, in my eyes, a crucial difference. And it will also give leaders a clear war goal, on that note. So too for 'protecting city-states' (if this idea is at all kept - I would vastly prefer the way RevolutionDCM naturally gives rise to city-state-esque civilisations), for example. Agendas, however, are but a tiny subset of personality or identity. Sulla once wrote this: "What happens when the religious powerhouse confronts the economic juggernaut? Who knows! Should be fun to find out." I would like to further explore that. The introduction of a faith yield is a good idea, and the separation of cultural and scientific tech trees - a bad idea, in hindsight - could have further supported this... But it doesn't. Endless Legends does, however, have civilisations that are drastically different - and why couldn't this be brought to Civilization, within the bounds of history? Already, we have many yields that can be used for many things. Why not expand upon that? You can purchase units with gold. Mercenaries. They'd be a bit weaker, probably, but of course, faster to 'produce' (instantly or not? Who knows). Perhaps mercenaries could be associated with tiles; mercenaries bought from desert hills would fight great in desert hills, for example, but far worse in tundra or snow. You can produce units the 'normal' way. With hammers (the production yield, for clarity) for equipment - the strength of a unit - and food for the manpower - the turns it takes to produce a unit. You could play with these numbers, of course; feudalism-esque things could decrease the required food - faster production speed - but also decrease the hammers, and thus, the strength. Buildings - such as a barracks - and resources - such as copper - could alter this, of course (copper is stronger than iron, but far less available, historically speaking - see also the 'bronze age collapse'). You can recruit units with faith. But their efficiency would depend on your continued faith output - how important is religion? - and that of your enemy. You can even recruit units with culture, perhaps once cultural levels are high enough, or once your city is drastically threatened - perhaps a combination of those, or perhaps depending on how 'aggressive' your civilisation is; do your people demand wars of expansion, such as, say, Rome, or the Flower Wars? - or once your civilisation has an ideology, or once a nationalism-esque technology has been researched... These would be little more than civilians given a weapon, but then, a nation focused on culture would hardly be warmongering. What all these systems do, however, is allow a civilisation to focus on one (or multiple) yields, and, though allowing all civilisations to achieve more or less the same, they will do so differently, with their own uniqueness (a military focused civilisation could get its yields from capturing cities and plundering science and whatnot from there, assimilating other civilisations' culture, integrating its conquered citizens...). And so, an empire focused on gold can actually go to war with a civilisation focused on faith - and what would happen then, indeed? Could soldiers be bribed? Or converted? What if the faith-focused civilisation is so overpowering, faith-wise, that it is like the medieval Pope? But what if the gold-focused civilisation follows the same religion - how could the gold-focused civilisation prevent outright rebellion from its own blasphemy? Civilization V slapped on all kinds of weird mini-game-esque things that seemed completely detached from the main game. I would take the main yields and use them to craft a distinct civilisation with them, giving so much freedom that practically every historical entity becomes possible to simulate. From the Carthaginian mercenaries and trade, to the merchant republic of Venice, to the Vatican - and of course, from Persia to Rome (empires with a different focus, mind! Persia was known for being very multicultural, so to say), to the USSR... The possibilities are endless. And they would bring back personality and identity in a very natural way. But they should flow naturally from base yields, and not be slapped on top of the game.