Often we see rules-light RPGs (like Fudge, Risus, the Window, Everway, or Cthulhu Dark) coupled with an improv-heavy, “hold your ideas loosely”, “build on your players ideas” super quantum-y GMing style.
For example, here is Cthulhu Dark, pp 46–47:
As you play, adapt the mystery, so that wherever the Investigators go, they find horror. […]
Whatever the Investigators do and wherever they go, they get deeper into the horror. Make it inescapable.
Not into it.
On the other hand, we see more blorby, prep-focused games use more detailed rules, like Old School Essentials or my own maximalist mashup of 5e, 2e, Wizardry, and Rules Cyclopedia D&D. + houserules of my own devising.
I think this is a bit of a mismatch in one way.
A looser prep can benefit from detailed systems—games like Sorcerer or Fate leverage this; Diaspora especially comes to mind with how you’d be loosily-goosily collaborating along and then you enter a subgame and play to find a hard outcome.
Conversely, a blorby and robust prep might not need much in the way of rules. I’ve been daydreaming of running a game with a big Silent Legions sandbox on the GM side but player mechanics from Cthulhu Dark or my own “Eventually” idea that I never ended up testing.
But not so much with the “adapt the game” style.
Instead, I want the backend to be solid, the mysteries to be real, the exploration and discoveries and choices to matter.
And, the example mysteries in the Cthulhu Dark book do have things to explore, to discover, to be curious about, and to realize. The advice section comes across as all “here’s how to railroad, here’s how to adapt and be quantum”, but then the adventures themselves aren’t like that, they’re good and solid.
I don’t use a lot of skill checks in my #boatmode D&D game, they can usually just do it, but as they do stuff, I count time, and that leads to encounter checks which leads to tension. Today, for example, they wanted to lift this huge big 12 foot diameter statue slab that was buried in the sand. I was like “That’ll take you at least 20 minutes” and they were like “yes, we wanna do it” and then down the line that lead to some pretty interesting characters from the encounter table showing up, some escaped former prisoners and their trauma added to the horrific themes of that particular dungeon level. The party thought that the escapees were the wardens, and captured them, and then the escapees went to desperate measures to not getting re-imprisoned alive again, and it got serious. All that off an encounter check, and only a one-in-sixty chance of this particular group of NPCs showing up. Love it.
And the encounter check is the core & only mechanic in Cthulhu Dark, disguised as a scene resolution system. You can’t really fail normally, and even with in situations where a failure die is in place you can make it if you push yourself, but roll a six & glimpse the horror, and with enough insight you risk losing your character. I could get into that if I had some solid prep. A huge Silent Legions campaign of truths and cults and metaphysics all laid out, crawling just under the epidermis, waiting to be uncovered glimpse by glimpse.