What you need, my friend, is the Carrot and the Stick.
Put simply, you reward the behavior you wish to encourage, and punish the behavior you wish to discourage. If your PCs are interrogating random beggers after you've made it clear that the only thing the beggers know is which houswives need some firewood chopped, punish them. In an RPG the worst punishment at your disposal is to be
ignored.Player: "I'm going to shake down the rest of the beggers. Someone must know something!"
GM: "Okay, you spend your afternoon harassing beggers. Meanwhile..." [switch to the rest of the group].
I would discourage you from using conflict as a form pf punishment; most players of this type have no problem fighting with the town guard,
even expecially when the guards are trying to arrest them for legitimately breaking the law. This also gives the player more face time and attention, which is what you don't want.
Now, when a player does what you
want, reward them. This need not be XP, gold or magic; instead, give them attention, make them look cool, and focus on whatever their PC values. Having said that, I use XP Awards: poker chips, each being wroth 50 XP/character level. It's an immediate, tagible reward and it's enough to be worth keeping track of, but not so much that it unbalances the game.
In a previous game, I already a character walking from library to library hoping to find some obscure tome that happened to be the GM plot notes. I told him explicitly that such would never exist (after the fourth library) and it would behoove him to try other routes of investigation other than research. Upon visiting the 6th library, I fully acknowledge I overdid it and had a riot break out and burn down the library he was in. The player is a highly intellectual type and has demonstrated this pattern over a series of games.
This player needs to be ignored when he continues on a course of action which you have blatantly told him was useless. If he continues looking through libraries, just smile, nod, and return to the other players. When he tells you his skill roll or asks what he's found, just tell him "Nothing yet," then turn away. He'll catch on.
I have another player who basically only plays non-combative spy types. I really don't mind the issue, until he refuses to work with the party in any way shape or form. He will usually slip out in the middle of the night and return just as the PCs are preparing for the day. (And yes he favors races that require less sleep.) This almost worked out against him once in a previous campaign when another character called him a traitor.
He
is a traitor. He's playing the Lone Wolf hero in a collaborative game; this DOES NOT WORK. "It's what my character would do" is the usual excuse for this type of behavior, and it's just that: an excuse. Tell him bluntly that he has to have a PC that plays well with others. He doesn't have to be all sunshine-and-rainbows, or even like the other PCs that much, but he *must* work
with them. No exceptions.
I have another player who for some reason only subscribes to his form of logic. For some reason he expects the common folk to know the deep dark secret of the warlock in the castle or for the maniacal zealot suicidal fanatic to be sane and actually follow his logic. No matter how many times he's been pulled aside and told about the environment or the circumstances, he seems unable to grasp the details.
As with Player #1, ignore him after the first two or three times he pulls this. "What? You're interrogating another barkeep? He doesn't know either." [turn back to the other players]. Some things are
mysteries; he needs to accept this even if he doesn't like it.
Is my attitude on this issue too harsh? Should I buy into the argument that the PCs know more than the players? I have attempted to meet the players half way by leaving clues in libraries in forms of old maps, and legends from the commoners. But that seems to have fueled the fire going the other way...now my players expect it. I understand nothing is more frustrating than when the storyteller refuses to tell the story, but nothing is more frustrating to me when my players just sit there begging for information.
Keep in mind at all times that any RPG is a cooperative game: the players give a little, the GM gives a little. If the players aren't figuring out your riddles and mysteries, you
have to help them. It's fundamental to the game. This may be frustrating, but is it better than having no game because the players can never figure out what they're supposed to be doing?
PCs
do know more than players...in the sense that they live in the campaign world and know the common customs, etc. If it's something Joe Schmoe on the street would know about (like, say, tipping 15% in most American restaurants), just tell the players. If it's something slightly obscure, allow an Int check.
I think you're in the position of a riddlemaker, to whom the solution is pathetically easy and blindingly obvious...unfortunately, the players are coming at it from the opposite angle, and find it much harder than you think it is. You carefully built the mystery to a logical conclusion; they are forced to reverse-engineer the finished product to find out how it works.
Regarding the skill checks: tell them that it's not possible to use them to find information that
does not exist in this time and place, regardless of what the book says. Invoke Rule 0 if necessary; the social/infomation rules are easily broken anyway. If necessary, give them a clue that points them in the direction they need to be heading..."The Mad Baron? There was a traveler through her 'bout a week ago what reminded me of him...eerie fellow; had eyes two different colors. He headed out thataway...'course, there's nothing there for fifty miles, save the old coal mine..."
Well; that took longer that I thought. Hope this helps you.
