Our heroes can't win Descent. We get murdered a couple rooms into every quest. Our Overlord isn't trying hard and he's killing heroes with ease. So far we've played the first 3 quests in the basic game (the last one twice because we died so quickly). We've read the rules several times, downloaded FAQ's and errata. All of us players are very experienced gamers. No tactic we try works.
1. What advice do you have for players to win Descent?
2. Is there some commonly-misunderstood rule that gets heroes killed?