One of the persistent problems of running a role-playing game, I think, is having to mediate between different levels of knowledge. Having new players who don’t know the rules is a problem, but it’s one that is resolved rather quickly as they get used to things– that’s not really what I’m talking about. The bigger problem as a DM is that you have all of these conflicting levels of knowledge about what’s going on in the game.
For example, if a party comes across an abandoned chapel in the woods, one of the PCs has to come to the realization that it’s a chapel to Corellon Larethian (e.g.) where it could just as conceivably be a chapel of Ehlonna. As a DM, you have a dilemma. The in-game mechanism is simple and reasonable; the wise cleric in the party does a Knowledge (Religion) check, and finds out that the chapel belongs to Corellon Larethian (i.e. is told by the DM). In addition, there’s also a level of common knowledge the players need to move the story along.
It’s lame and immersion breaking to have the DM tell the whole party, ‘No, you know, Corellon Larethian, the god of the elves (hint, hint– remember the elf you met earlier)’. And it’s also lame if one of your players steps out of character (even though she’s playing a half-witted orc rogue) to point out the obvious elven character of the chapel.
One solution is to keep such specialist knowledge out of your story. But part of the fun in DMing is playing around with the lore and giving your story arc deeper resonances.
I imagine there are a number of ways to resolve this problem, but I came up with one while I was walking home today. One could give each player something akin to a course packet, with photocopies of relevant sections from whatever source texts you’re using. This allows you to use whatever source text you like (instead of having to keep to the well-beaten path), or also to interpolate things the DM’s written to give texture and content to the fictional world.
This gives all of the players a common pool of knowledge to draw from, and allows each player to mediate between their level of knowledge and that of their PC.