Text > Choice Branch > Random Factor > Effect > Loop

But wouldn't it require stats (like "Stewardship" affecting the random factor)?

Also, the big question, what "effects" there could be (let's say we are talking about some generic 4X in space)? I mean, how exactly the storyline tie to the 4X experience/mechanics?

Well take it back to the Dune reference. (Writing this up and I'm realizing how long it has been since I actually read the books. Assume that the following contains spoilers and mistakes, but close enough to get the gist for game design.)

At some point the Emperor was faced with Liet Kynes and the decision as to whether or not to allow him to start doing his massive ecological survey. This decision becomes a branching point in the Dune series with various possible outcomes. Allowing him to go unlocks a route that potentially enables Paul to overthrow the Emperor far down the road, but denying the request to start the research might either close that story branch or open a new one where Liet Kynes meets someone at court and and whole other chain of events might start to unfold. Maybe he meets up with a group and an assassination plot begins, or a plot begins and he discovers it and saves you.

Depending on how you are doing in the strategy side of things then different storyline events may trigger. Have you just failed to suppress a rebellion? Then you've met conditions under which different events may trigger, possibly so and so in a neighbouring sector will rise up and lead another rebellion because he sees that the empire is weak. Or maybe person such and such will rise up in the recently rebelled provinces with a counter-revolution, because your previous story line choices gained favour with her and her family, and she feels that her people are better off being in the fold of the empire rather than on the edge of it.

Your story scripting would ideally include chances with which ways given choices swing, simply to keep it hard from trying to repeat the same game twice in a row.

The core choice you have to make is, how big is your cast? How many factions are there? Do you want "Random" people to come up and be generated at runtime, or do you want to keep the storyline to be tightly focused with a dozen or so 'names' weaving the story around the emperor?

Also, what story do you want to tell?

As for your random factors, they can be a simple as laying out options in the script. Option A has a 50% chance of firing, B 30%, C 19% and D is 1%. User might see some of the odds when making a choice, or they might have the odds and effect hidden from view. The point of the random factor would be to add some flexibility and surprise into user choices, and some risk/reward. If Choice A always has a more positive out come than Choice B, then you'll want to pick it. But if Choice B usually is worse than A, but has the chance to be far far better on a good dice roll, then maybe you'll take it on some games instead, depending on how things are going for you.

The more I think about it the more I find the need for a storyline in that game :)

Depending on how you are doing in the strategy side of things then different storyline events may trigger.

Hmm, I was thinking the other way round. The story is given (more or less) and it affects the strategy side (triggered a rebellion, bonus/penalty to the Empire). I feel that if the strategy side would to generate the storyline it would be unplayable/boring.

"At some point the Emperor was faced with Liet Kynes and the decision as to whether or not to allow him to start doing his massive ecological survey." - like here, the player is given this choice and then the game tries to find a suitable planet for such terraformation and sets it as special and links to the story engine.

Also, what story do you want to tell?

A story about an old bureaucratic empire. With expansion, corruption, rebels, disloyal officials and so on. I don't want to tell CKII kind of story (dynasty focused) but empire focused.

The core choice you have to make is, how big is your cast? How many factions are there? Do you want "Random" people to come up and be generated at runtime, or do you want to keep the storyline to be tightly focused with a dozen or so 'names' weaving the story around the emperor?

I'm fine both ways. I think smaller cast (storyline wise) would be better, but I prefer a bigger cast on the gameplay level (strategy wise, like planetary governors) to convey the grand scale of things.

As I see it now, I probably should split the storyline cast (imperal court, advisors, factions) and the gameplay cast (admirals, officers, governors, ambassadors)...

I feel the best way to handle this might be to use the storyline to modify/branch out the 4X part of the game.

Like: An alien ambassador has eaten your citizen, which is customary to that race. And you are faced with a decision of internal problems (you let it go and your people are angry, +10 to rebel support) or external problems (you make this ambassador persona non grata which angers the aliens, -5 alien relations). Or you have an option for a special one time tax (money vs people happiness).

So, by the use of the storyline options the player would be able to decide which way the 4X game goes (more rebellions or more alien invasions, etc).

Also there should be some longer storyline (chain of events, sort of) in addition to the independent events above. Like the galaxy was inhabited by an ancient race and you discover about them as you go (people coming to you and tell you about it in the audience) and make some decisions (if to focus on discovering their technologies, finding their homeworld, incorporating their culture into yours, make a claim you are the descendant of them therefore making you stronger diplomatically).

Also I strongly feel there should be some sort of conspiracy/usurp plot :D Someone trying to stab you in the back (each game someone else) and you trying to discover this/counter it.

Note: I you have more ideas for plots that could fit here, post. It does not need to be 100% about mechanics.

Civlization : Beyond Earth does this via quests and random decisions. It's more of a "decide whether to get more of resource x or y" in reality, but the story bits sound good. Then again, basic resource exchange is what most storytelling is build on although the resources are usually reputation and emotional state.