Moving in the Shadows

The question of what a player should and should not know is important to any game. It also happens to be one where people hold many different opinions. Some say that there should be near-total transparency; this is the approach taken by individuals such as Luke Crane, author of the Burning Wheel system. He views roleplaying as a collaborative drama between players and GM. Thus, players shouldn't be surprised by anything, even if their characters are. In stark contrast to it stands a system such as White Wolf's World of Darkness, or the Call of Cthulu RPG, both of which are aimed at horror, and where the players are told nothing. After much gaming, they may know more than their characters, simply because of out-of-character knowledge, but this isn't a conscious decision.

The Praises of Mystery
Mystery and the unknown can be a marvellous tool. When a player doesn't have all of the information, it places them in a position similar to that of the character: a bit lost. This is not always a bad thing. It encourages them not to see their situation as merely one movement in a grand scheme, but also as a very personal moment. In that moment, they can far more readily invest in their character, and not just as an actor in a drama, but as a person, who's limited like them. Their limitation becomes an advantage, and the storytelling gains.

Of course, mystery is also handy from a GM's point of view. With mystery, he can tell a story and weave the characters' own stories into it. Mystery ensures that if there are gaps, they don't have to be addressed all at the start. This makes threats and story elements malleable. This means that the story can truly be shaped around the characters.

A Specific Dynamic
Using mystery demands that you know what the dynamic of the GM and players is, accordingly. A campaign which keeps players in the dark about many elements is a game where players are participating in the story of the GM, somewhat like an interactive play. The general theme and events are decided by the GM, but they can be changed and interacted with by the players. This can be a good thing, or a bad thing. For it to be a good thing, the GM must use this power to make a compelling experience for the players.

Key to this is playing off of the PCs. They have talents, specialties, and also specific hopes and fears and so forth. A good GM should engage these in the plot, implementing them tighter and tighter, so that the ending brings all of the PCs together into one "story moment". The GM can't use mystery as a way to shoehorn the PCs into his own story. The GM has to work with the players.

Mystery can be a great tool. Use mystery right, and the players can feel like they're living in a grand story.