There's an inbuilt assumption that I've been working really hard to overcome for a long while. I feel like I have a lot of these little confessional moments about ingrained assumptions as a DM that I'm working on. I don't know if that makes me whiny, or a bad DM, or just cognizant of my weaknesses. But that's besides the point.
The assumption is that only the player characters matter. What do I mean by this? CLEARLY for the content of the game, the player characters are the most important element. They are, in a sense, truly the only thing that matters because without them as a stepping stone into the game world the players would have no way to interact with anything and the game would be something more like a book and less like a roleplaying game. But in this particular instance, I mean that the actions of the player characters are the most important elements in the game world. Essentially, the idea that the world is a collection of events that were already going to happen and that without the player's interference, things usually degrade. EG, don't go and kill some ogres? Well, later they are much more dangerous and smashing up caravans instead of just terrorizing the local peasantry.
This is a good quick short-hand for consequentialism. You did or did not do X or Y, therefore Z or possibly W happened. I think that's a great lead-in for fresh players to understand the game. But consequentialism in D&D can be a lot more complicated than that. I have to remind myself that the players are not the only power in the region. They aren't even the only adventuring party. So things may resolve in a way that is more or less in line with what they were hoping for, but they shouldn't invariably degenerate without player input. It's almost as though the setting is a watch and the players need to go around winding parts of it to keep the systemic entropy from increasing and increasing.
That sounds like a fun game, actually.
But while having consequence-chains be completely beyond player anticipation or outside their frame of reference is frustrating... The world always counting on the players to solve things can be frustrating as well. It can foster a sense of immediacy that means PCs must accomplish every action all at once. This completionist feeling is arguably just as dangerous to the gameplay.
So, I've been thinking of making some charts to represent what happens to adventures when PCs turn them down. In the same vein, I've been thinking of making charts to represent how complex political situations resolve themselves so I'm not just deciding based on what I think is appropriate. That may work in some cases, but sometimes I want to be surprised -- does the attempt at a coup succeed? Fail? The dice can tell me and I can interpret their results.
Since these things are somewhat abstracted (they're happening "off stage" so they don't need to be granular, and without direct player interference so they don't need complex rules governing PC interaction with them) these charts can be as simple as the sample I'm going to provide right here:
What Happened to that Quest/Hook?
01-20. Things got worse. There are more goblins, more dangerous wizards, or some increase in stakes.
21-30. Things got worse. Another adventuring party tried to solve it, but failed. Their failure has made things even worse than before.
31-45. Things got worse. Local militia or knights tried to solve the problem, but failed terribly.
46-55. The problem went away or resolved on its own. No action was necessary.
56-70. The problem was solved by an adventuring party. It's all good.
71-85. The problem was resolved by local forces. It's still all good. They may have gained some levels.
86-90. Whatever was wrong has caused another major issue to spring up. At the DMs option, they may both be problems now.
91-95. The adventure was exposed as a political manipulation, maneuver, or front. Whoever had the "issue" has been outed as having set everything up.
96-00. No change.