Rumors on the dungeon.

 For rumors about a dungeon that the DM gives to the players before they go: if they could be a lie. 

Then I'm inclined to disregard them all. I'd rather not indulge any of them if one could be a lie. 

This is an overly pessimist view. 

How do you do rumors and what are your thoughts about them and what have you learned in using them? 

Do you have a philosophy about them? 30% true, 50% half true, 20% lies? 

What's the design point of rumors? to wet the players appetite? To give them clues of what they'll be facing? A clue on how to beat them? 

If they can be lies, then is that to intentionally misdirect them? 

What if the rumors are only true and half truths? 

I don't have answers for this. Rumors certainly aren't needed but they could be a hook for why the players are going to this dungeon. Maybe that's reason enough?

Something to experiment with....