One might define this as Setting In-Game Goals (or having them thrust at you) that contribute to you or your people's definition of 'Victory'.
"My Theocracy converted 100% of my own population to Our Religion by 1032 CE - Victory is Ours!"
- only it really isn't, you have just achieved a self-defined Victory Condition that contributes to a Game Victory overall.
That's related to the 'Fame' mechanic in That Other Game in that 'Little Victories" are going to be defined or become available based on the emphasis of the Civ: religious for Theocracies as per the example, military for militants, Money/Gold for traders and commercial states, etc. But some are going to be strictly Conditional: a completely non-militant Civ attacked by some would-be World Conqueror that fights him off decisively - that's a Victory, and one unlooked-for by that society/Civ/Player. That kind of mechanic would keep the entire system Dynamic and somewhat Unpredictable: actions by other Civs or players (Barbarians, City States, NGOs, etc) could affect what precise 'Victories" become available or desirable, regardless of what little game you thought you were going to play . . .
I very much want to keep this thread going (snowballing, even) and, fortunately, have finally had brain activity congeal into a thought in reply to this post.
It's sort of like the Events and Decisions system, right? Things pop up, which describe a thing to do, and costs and benefits to the choice, but it's not just a choice, it's an achievement you have to reach from there, and with a deadline (or other restriction, like "Accomplish Z but don't do X , where X is something that mechanics make you inevitably need to do but we aren't going to define that time limit except in reference to the X mechanic.") And, like the Events and Decisions, they are triggered by tags of the current state of your civ. What era it is. What government it is. Having a story-rich tech. Being a specific civ, even. Being a theocracy in a certain context presents you with a "mission" of religious dominance, and that lets you develop if you do it, for example. Or, working with a technology gives you a mission to employ it to a certain breadth, and that gives you more research, for example. Or it could give you the victory points alone.
But, I don't like randomness. So here's what I imagine. The event pops up because you met the requirement, plus also something else deterministic that you can work on. I really despise both "Influence" meters and "Stability" meters for reasons I won't go into, but if any meter for generic top-down edicts of empire decisions I would tolerate, it would be such a meter. A meter you must fill, or spend from exorbitantly, to actually -do- an event. Doing so will mean the cost of not taking on another event.
But here's a
variant of that idea. Instead of having a meter, make it a drafting system. The event comes along as a card in a shuffle with other cards that apply. You draft and other player's draft.
OR , you have meter and the cards, and you "bid" for the card to get it.
OR, setting an event up applies to all players, so you want one that you will actually win and you might actually help a rival. <- this one is an issue with team-play problems, so actually I don't like it.
Mainly, the variables for this system are: Does an event happening for you mean it doesn't happen for others, or do you both get an event which you each run the gauntlet for independently (and can each win or lose)? And do you choose the event whenever you want, or do you give up attempting other events at the same time?
Of the second variable, if you use a meter, then you afford the potential for growing that bar so huge that you can spend like Mansa Musa in Egypt and not give a $%#!, ... which could be a snowballing thing, unless the meter didn't grow with empire growth. And at that point why even make it a meter. So instead of a meter, it's just you have events and you pick one and that means you're not allowed to take on another right now (or the maximum is 2 or 3).
.... Or, maybe you get the event and you do face them all and this is a bad thing because working to more than 2 of them will stretch you so much you couldnt possibly succeed. And at that point you might pay something to -not- have an event apply to you. Then meter would be interesting. Would it snowball? It would kinda be like... what money yield is in Civ right now; a yield that gives you flexibility saved up but is very much weaker than hammers or science or even food (early). You use it to get out of a problem that would rough up a plan of yours.