Converting White Plume Mountain, Part 1: What Level Is Appropriate?

White Plume Mountain strikes me as a good choice of an old-school module to convert to D&D4. It's effectively three separate chains of encounters, from which you choose very early in the dungeon. Should mesh well with 4E's style of adventure.

(There's a 3.5 conversion here, by the way.)

First part is to figure out what level it should be aimed at. My hunch is "somewhere at high heroic level", but a more exact way would be to look up the monsters in the adventure and see where they land at in their 4E versions. So let's go:

Existing monsters:
Black Pudding (L8, Monster Manual 2)
Bugbear (L5-6, MM1 and 2)
Gargoyle (L9, MM1)
Ogre (L8, 11, MM1)
Wight (L9, 12, MM1)
Green Slime (L4, MM2, maybe best handled as a hazard)
Flesh Golem (L12, MM1)
Ctenmiir (L13, Open Grave)
Ghoul (L5-13, pretty much every book)
Giant Crayfish (L4, RPGA adventure Village of Hommlet)
Manticore (L10, MM1)
Efreeti (L22-28, MM1)

Close enough
Gynosphinx (Sphinx L16, MM1)
Air elemental (Air archon L16, both from Manual of the Planes)
Giant Scorpion (Hellstinger Scorpion L13)
Quesnef the Ogre Mage (Oni L7-14)

Need converting
Invisible Stalker
Shadow
Kelpie
Giant Crab
Sea Lion

NPC:s:
Burket
Snarla
Bluto Sans Pite (and henchmen)

(Level ranges have been cut after the fact, reducing them to levels actually relevant to the result. Ghouls and wights, for example, exist at a much wider level range.)

Putting the adventure at level 11 would make most encounters work, with some level-changing. (The first five existing monsters are random encounters, so it's okay if those are a little easy.) It also makes most of the classic encounters (Ctenmiir, for example) work nearly as written. Still, many of the enemies need friends to make for interesting encounters (Ctenmiir, again.)