Chris Lehrich makes some great points on the Forge about creating mysteries and playing in mysteries. Of particular interest are his thoughts on “abduction”, wherein players will create theories and then have their characters test those theories.

When confronted with a mystery in a role-playing game, it isn’t enough to listen only to the clues that the game master recites. These are only the obvious things that any person would see. The game master cannot foresee all possible clues that might be left by the situation in question. So, not only does the game master need to be open to the possibility of player characters searching unexpected places for unexpected clues, but the players need to actively make theories and test those theories by making predictions about what they should find if the theory is true.

Chris calls this “abduction”, taking it from C.S. Pierce. Abduction is a way for players to use induction and deduction in the game world.

If the players are working abductively, they will create clues of their own accord, then seek them out. That is, if they hypothesize that the killer must have run across that flowerbed, they will realize that it will help the Case immensely if there are footprints in the flowerbed. If the Case is accurate on this point, the GM has them find the footprints.

This means that the GM's job is to have a clear Case in mind and to work very strongly on Deduction, prior to the game, to figure out what the clear Results will be.

Chris also breaks down the means by which mystery-game players can solve a mystery in an exciting manner. It’s all interesting. The most useful for gamers in general, however, is his descriptions of abduction and how players construct and test theories for what is going on.

Role-playing games are interactive in a way that other games have not yet reached, and which current technology cannot reach. Players can have their characters interact with every single part of the game world, regardless of whether the game master has written notes about that part of the game world. As long as the game master knows basically what is going on, they can extrapolate, and players should take advantage of this.

Think out loud

A lot of this can be described as “thinking out loud”. Create a theory, out loud, so that everyone can discuss it--and so that the game master can hear it and apply it to what the game master knows really happened.

1. There are some things that the players will find without asking. The dead goblins in the moat, the skeletons in the mess hall, the glowing fungus behind the temple. If their characters see the moat, enter the mess hall, or go behind the temple, they’ll see these things without having to ask.
2. There are other things that the players will not find unless they search more deeply, but which exist before the players think about them. Yes, there’s an awfully small space between these rooms, and it would make sense for there to be a passage between them. But we don’t see one, so why not look for a secret door? Most likely, however, the secret door is on the game master’s map (or, if not, it won’t be found), regardless of how well the players theorize.
3. But there are some things that are so trivial that the adventure book would have to be the size of a metropolitan telephone book if the game master were even to attempt to write them all down. Here is where theorizing and testing helps the players and adds to the game. “If this was a mass suicide, then there ought to be some record, such as a suicide note or farewell note from at least one person.” The fact that the players haven’t found one yet means nothing unless they’ve made the theory first, because the game master isn’t aware that this is what they’re looking for.

There is often an assumption in mystery-oriented games that there are clues out there, and all the players have to do is find them. And in a sense this is true: but the clues are not always created until the game master thinks of them in response to inadvertent player input. Theorizing out loud moves this input from inadvertent to deliberate, making a better game for all players. The world is a big place, full of tiny items.