Continued from here.
Lord Gusorio sipped his mead and smiled broadly. "The finest giant bee's honey, turned into the finest drink. You know, there's a story behind this brew."
The young treasure hunters leaned in, awaiting yet another tale of the baron's adventures with his famous companions. Gusorio paused to savor their attention for a moment, just as he savored his honey wine. Finally, he spoke. "Rashni had heard a rumor from some vagabonds who'd tried their luck in the Great Dungeon. They said there was an enormous hive of giant bees deep in the third level. From what exploring we'd done on that level, we knew there were plenty of bees flying around here and there.
"Well, one time, we set out into the dungeon to track down that bee hive. We wanted the honey to make healing potions. You know Old Helga says it's good for that. Well, we got the honey, and we fermented it and got the best mead in the kingdom instead of healing potions..."
Sometimes, a party hears a rumor about the dungeon. Or they discover a treasure map that promises great reward. Or they've discovered something early on that didn't benefit them at the time, but some mishap has occurred and they wonder if it might help now. So they set out into the dungeon with the express purpose of finding out if the information at hand is correct or not.
This sort of expedition is similar to a scouting party, but differs in a few important ways. First of all, on a scouting mission, the party may have an objective, but it's usually fairly vague. "Let's find a stairway down to the second level." "Let's see what's down the long corridor that leads south from the owlbear's lair." "Let's finally map the Twisting Maze."
On a Fact Finding expedition, the party has a bit more specific information. It may not be true (rumors often are not, and maps can be out of date), but at least it's something solid to shoot for. The party may have found a rumor of a rich treasure, a magic item, a fountain of healing, a friendly or at least neutral monster that acts as a sage, or who knows what else? For whatever reason, the players want to find out if it's true, and take advantage of it. Sometimes, they may just be curious if such a thing exists (and using Jeff Rients' exploration XP awards can actually make this valuable to the players as well).
On such an expedition, the party may decide to equip themselves as if on a scouting expedition--lightly armed and armored, and with enough utility magic to tackle logistical problems. But at the same time, a more mixed approach might be best. To find that mystery, a few battles may be unavoidable. In such cases, some heavy armor for the Fighters and Clerics is always good. A sleep spell or fire ball might not hurt, either.
Fact Finding Missions are sort of like many site-based dungeon modules, in that the group usually has a certain goal, an idea of how they might achieve it, and they're not just out to bust a few skulls and fill their coin purses. But because it's happening in a Megadungeon environment, it's often something the players decide to do themselves, rather than simply being the result of a plot hook thrown out there by the DM.