Dr. Strangemonkey said:
Ooo, I was thinking of trying to run it with three people. Ah well, at least one of them is jonesing for an above 20th level experience.
Either that or it might be a good impetus to recruit new people.
If you were open to the idea, you might consider running characters as gestalt characters based on rules from
Unearthed Arcana. It gives the players more option without overpowering them, and it can be a decent balancing factor against a module set up for six people.
EDIT: Yup, read the WHOLE thread before posting. ^_^
I believe UA is OGL, so here's the skinny:
Take two core classes. Take the best of both -- Hit Dice, saves, weapon/armor proficiencies, number of feats, skill points... apply all class abilities. Example: A Fighter/Wizard 1/1 gains 1d10 HP, simple/martial wpn proficiencies, F +2 R +0 W +2, spells, Create Scroll feat. As you increase levels, up whatever goes up at the best rate, add new skills/feats (but don't double up feats).
It gets trickier when/if you throw in Prestige Classes, but the same theory applies. All class bonuses, but the player picks which class goes up (Ex: if the Fighter/Wiz become an Arcane Archer, he has to decide if he gets the benefits for his Fighter or Wizard class when he adds on Arcane Archer, then takes the best of both as usual). Take the PrC's that are similar to gestalt characters off the table (Mystic Theurge, Spellthief for example)