A game idea:
GM, come up with a conspiracy plot. Some scheming faction is up to no good. They're doing many things to further their plan, some of them suspicious. Come up with something you're excited about and think is cool, something you're eager to share.
Now come up with a bunch of red herrings and deceiving appearances. What does it seem like the bad guys are doing, but they're doing something else? What's going on that seems like their fault, but is actually someone else's? Who else out there seems like a menace but could help, or vice versa? Again, come up with stuff you like and want to share.
Players, you're playing characters who have to get to the bottom of this, no matter what, because they're that kind of hero. They also have a lot of other things they care about, which the badguys will threaten or destroy, lending angst and tension to the mission. Come up with 5 categories of stuff you care about and rank them 5 (most important) to 1 (least important). Example: 5-son, 4-spouse, 3-body, 2-job, 1-gold watch.
GM describes everything except what the player characters think and attempt to do*, including the outcomes of any attempts. GM can even position player characters via scene framing. GM's goal is to show players enough fictional happenings that they can form theories about what's going on. For this, you will have to be a good storyteller. Use all your best tricks!
GM, once per scene, you should also introduce a situation that threatens to damage (subtract 1 if value >1) or destroy (if value = 1) something each character cares about. If the players doesn't block this, it happens. *GM cannot damage or destroy these valued things beyond the "once per scene if not blocked" rule.
Players, you earn the following points for doing the following things:
1 - sharing a theory with the other characters on what's going on -- not a quick and idle mention, but a strong argument
2 - sharing a theory and taking action based on that theory (if you don't know what action would work, just state your intent, and the GM will tell you how to pursue it)
Players, you can spend points on the following:
- block harm to the things you care about, 1 for 1
- win the final showdown at the end of the game; once you've uncovered the plot, foil it -- each point becomes a die to roll vs the GM's 10 dice
GM, every time the players act in pursuit of an incorrect theory, reveal one of your red herrings and then show them more of your plot. Every time the players act in pursuit of a correct theory, reveal some truth about your plot. When you're all out of small truths, it's time for the final Big Reveal and then the showdown!
GM, if you are stumped and it's ceasing to be fun to push your planned plot, just throw in random ominous occurrences, wait for the players to theorize, and then decide that one of their theories is true. Repeat as many times as needed or desired.