I tried to look at running Night Below in 3.0 and the first encounter with 5 bandits would have been way over CR for a level 1 party and they would all have died
Oh please do! I've actualy converted over half the npc's into 3rd Ed already (and should be able to update them to 3.5 no trouble).
And by over half, I mean all the hostile npc's from the first book and most of the ones from the second (but by no means all of them, or any of the third).
The thing with doing Night Below with 3rd Ed is that you end up being around 20th level by the time you reach the City of the Glass Pools instead of 12th so the stuff either needs some serious upgrading, or you need to downscale the xp a little. I generaly find 3rd Ed recommended xp handouts to be a bit huge for my tastes. If you give them something like a quarter to a third of the recommended uber xp ammounts, they'll level at about the same rate as they would've done doing it in 3rd Ed, and the encounters will all be roughly balanced without the need to upstat anything to make it challenging enough.
Funnily enough, when I ran Night Below for 3rd Ed, the starting encounter was a lot of fun. Since the npc's they meet are posing as lumberjacks, I had them meet up the night before at the lumberjack's camp. The two guys with the wagon fed the party, shared their dinner etc, but didn't dare tangle with them without backup. One of the lumberjacks, Brud, was a likeable fellow and the party really loved him.
So later the next day, as the party wizard sat in the wagon, an arrow came thudding through the side of the cart missing his eyeball by a mere fraction of an inch. He almost fainted.
Brud and Cleb shouted about bandits and, grabbing logs from the cart (to use as clubs) headed for the trees.
From that point on, stuff got nasty. A sleep spell simplified things but then Brud the Log Man managed to knock out three quarters of the party with a mere log! We're talking about a 1st level warrior (wearing no armour) bearing a log concussing 3 or 4 characters in a row here!
Brud the peasant is now a legendary character
My main piece of advice for Night Below? Rename all
the npc's (because Monte's Chellinifferiffer names aren't funny and they just piss me off, in my cvampaign Tauster the wizard became Terrick or Theothrastus, and his missing apprentice with her really crappy Jelleneth name became Chenna
I've been considering posting a Night Below suggestion for the last few weeks but it gets mentioned a lot on audio and I'm not sure how much you guys loved/hated it the last time round.