Check out Samhaine’s Player Tricks: Solving RPG Mysteries. It makes a fantastic companion piece to the Three Clue Rule.
Basically, Samhaine gives you a great overview of techniques players in an RPG can use to solve the mysteries presented to them by the GM. Broadly speaking, he breaks the solving of a mystery into three categories:
Deduction is the one most players are familiar with, particularly from published scenarios, where the players assemble so many clues that there is legitimately only one conclusion that can be drawn from them. The GM doles out unmissable clues as the game progresses (faster or slower depending on how aggressive you are, how your skill checks go, and whether you make bad decisions), and eventually you have enough puzzle pieces that the missing one is completely obvious. Even at its fastest, waiting for clues until you can work up a deduction tends to be really slow.
Induction is most useful at the mid-ranges of an investigation, because you take incomplete evidence and try to extrapolate something that explains it (but which might not be the only thing that explains it). Often, it’s the trick you use for figuring out if there are any other things you need to check before deciding you’ve got it all figured out. It’s your main way to generate falsifiable theories: we know a bunch of things, and it seems likely that X would explain them, but something else could explain them. Let’s figure out how we can prove and disprove X; if we disprove it, we need to think about these other clues in a different way.
Abduction in this context really means brainstorming to come up with logical explanations for clues based on known rules, which give you immediate things to check (such as whether those known rules don’t apply in this case). This is the thing you do when you don’t know much at all yet to try to figure out more things. Abduction is where RPG mysteries really diverge from scripted ones: you can jump the clue sequence pretty much whenever you want by working backwards along what seems like the simplest explanation. “The murderer got into the house somehow. One of the ways he could have gotten into the house was the nearby window. Thus, we can check to see if that’s how he got in!” Hopefully your GM has prepared enough for a lot of this tactic, because it basically means trying to skip straight to the solution using common sense and hoping proving or disproving your theories will at least narrow down the idea space you should be looking at.
And then he drills down into those categories to explore specific tips, consequences, and general fallout. It’s incredibly clever, broadly useful, and very much worth your time.
