I was actually thinking of running this campaign soon, but with all due respect to Gygax I really dislike the excessively random screwing around tactics he sometimes used(i.e. save and lose anyway effects). So I was looking to compile a full list of the houserules used in this campaign along with their intended purpose, and then see which of those are both useful and acceptable, and then look at what other houserules are needed to create the desired effect.
The basic premise of this is a self contained dungeon and you are meant to have very limited access to the outisde - I can work with that as a starting point. The justification of the celestial backstory - well I'm not so convinced by that - something along the lines of the crazy dude from Undermountain (Halaster?) makes more sense to me. And it being a an actively maintained magical prison might help with some later justifications - I'm not sure about this change yet - I'm just leaving it open.
So here's a list of the houserules I find in order from the book and what I think of them.
1. No baby monsters, cos heroes don't kill babies. Hmm, well first off I don't assume the party is necessarily 'heroes', but even a relatively neutral party could be heavily slowed down by a more 'realistic' eco-system, assuming they weren't using the controversial logic of evil baby monsters are evil. "A wizard did it" covers a lot of things, but I think it would be more interesting if there were some baby creatures in some places and not others - could lead to some good roleplaying without creating an instant moral deadlock.
2. Ecology - the food issue - not really a houserule as such, more just a list of options and pick one. Tbh large underground comminities always need to resolve this issue anyway, although the closed environment creates some extra problems. Magically created food of some sort seems best - maybe food appears next to anyone in the dungeon when they wake - or to promote more fighting it always appears in certain areas.
3. Darkness - Because I'm starting at the beginning of the book I don't know how common the areas of light are, but although I would normally have more magic lamps, glowing lichen etc, I think large areas of darkness are fine - but some of the creatures living there may have added more lights if it seemed benefiicial to them - darkvision in most cases has a really short range - and it could aid them against things sneaking up on them.
4. Sound - sound travels as far as the GM wants it to basically. This actually seems a handy tool and is easy to rationalize so this seems fine as is.
5. Traps - again not really a houserule for the campaign because it basically says put them where you want - hardly needs said really.
6. Lockpicks - Hmm - basically it's saying these break easily and when some of the tools are broken you get a penalty - and of course it's difficult to get replacements. I can see that been an interesting problem for the early character levels - up to about 5 say, but it would get pretty tedious after that - especially since lack of tools would be keeping you out of interesting areas to explore. Arranging for the PCs to get a more sturdy magical set would seem to be a good solution here - because otherwise you are really just encourging the PCs to arrange a more permanent magical solution (e.g. Warlock) or using the fighter lockpick - no reason to solely pick on the rogue.
7. Teleportation and extradimensional space - it's a null field that negates all extradimensional travel and teleportation within the dungeon - although you can use such effects to enter the dungeon. Some areas don't have this effect and some have random teleportation traps instead. There is an option for giving certain creatures a limited range of motion on the ethereal or shadow planes (basically to allow blink effects etc), and also an option for LOS teleportation. I can certainly see why they want to heavily limit teleportation and access to other planes. I think a neat to solution to blink etc might be to have the prison fully enclose it's equivalent areas on the ethereal and shadow plane - basically you can go there to pick fights with stuff and can use spell effects that rely on those planes, but since those areas are part of the dungeon too it doesn't let you out or aid with finding a space to rest etc. Extradimensional space I'm not so sure about - I really like my rope trick and bags of holding. Maybe an alternative would be that people can access those spaces even if they normally couldn't - so people can break into your rope trick so it's not completely safe. It still removes a lot of danger though, so I'm not sure.
8. Treasure. WBL is so strongly built into character's power level that I'm really not convinced they thought throught the limited loot properly. It should certainly be much more difficult to get the items you want, but since there are surely a significant number of tool using creatures in the dungeon with an equal need for the tools for survival I do not think getting hold of reasonable options should be too tricky.
9. Experiance - capped to twice per map. I never use the standard level anyway after reading Frank and K's stuff. 3 months to 20th level or whatever is just silly. I usually try to aim to level the PCs before they get bored of their current abilities, but after they've had a good chance to play with them - twice per map will probably fine, unless they spend too much time wandering in circles(maybe becuase of problems with locked doors and scary monsrters perhaps *cough* *cough*), They also mention some other options for other ways to reduce xp. People in this thread have suggested using the other xp that would otherwise be lost as a pool for items and stuff - maybe could use that Ritual of Transferance to give it to an NPC artificer if the PCs don't have one of their own.
10. Bardic lore - cos no-ones heard of this dungeon until now. Hmm - given some of the really obscure shit bards can know that's just blatant fiat. I think it should be possible to have heard it but no-one escaped from it before - so without significant interaction with the natives you takes a penalty on rolls - and that penalty reduces gradually based on how much they talk to npcs. Their idea of useless skills is pretty laughable too. Sure some of them would be reduced in usefulness compared to a normal campaign, but it's still not going to be a pure combat fest - so the social skills will come in handy - and bards always need perform - duh.
11. Wizards and their spellbooks. - I'm not really keen on taking away a class feature. It's going to be much more difficult to get individual spells you want - but you should still get some. There will be NPC wizards - and some of those would be quite keen if not desparate to trade surely. The bizarre option for basically having your mentor's spellbook (so you pick them all ahead of time), was a bit out there - but could be very interesting. The option to allow wizards to learn from divine scrolls is also interesting, even at a penalty to Spellcraft. Entangle and web - too devastating to be allowed in a dungeon apparently. Bugger that. I'm not forcing people to go back to playing AD&D with blaster wizards and healbot clerics. Spell per limits will work fine - it's no worse than a standard campaign with hefty amounts of underdark exploration or whatever - standard D&D games spend a fair bit of time in dungeons anyway.
12. Random encounters - hmmm - I've never actually used random encounters before. I can certainly see they fit well with this campaign, but I can also see them bogging things down immensely. I can see me rolling some dice pretending to check for random encounters - but I think I'll stick to my usual policy of picking them to advance the plot and action.
13. Summon monsters - because they can't leave something has to be done to discourage PCs (and NPCs for that matter) from summoning an army. Oh and the rationale for demons not summoning an army is too flimsy to be accepted. So either summons don't work or they have some sort of downside - that affects all types of summons. Since teleporting into the dungeon works it would be inconsistent to deny summoning entirely. The going mad or berzerk option also seems inconsistent - as does them dying at the end of the duration. I'm not really sure how to resolve this one.
14. Druids - wtf? Are the designers completely unaware of subterrainean druids? Druids normally adventure in dungeons just fine and there's nothing in this book to change that. The odds of finding an animal companion underground? About the same as aboveground dumbass. The large number of creatures in the dungeon should surely provide some options for learning of appropriate forms to take, Druids should all have maxed K(nature) anyway, and they get a small nerf because of whatever is done to the summon spells. Other than that they are their usual kick-ass self. I think Druids would be quite interested in this unique eco-system.
15. Skill use - this is the bit on p19 that has some really arbitary crap to muck about with skill DCs. It sounds like they have a general issue with take 10 and take 20 and are using this sidebar as a forum for bitching. I don't agree with their points or like their tone - if I was a player and a DM was using these arguments I'd would only be playing if I was desperate for RP - mostly I'd just tell him to shove it and go elsewhere. I don't really see any reason to change the standard dynamics here, other than maybe to occaisonally point out to the PCs just how much time this is taking, and that maybe their characters would be getting a little bored by now.
And then it delves into the huge emcounter list and I didn't spot any more rule sidebars. Please let me know if I missed anything.
So basically aside from developer insanity the basic issues are the lack of access to the outside world and the equipment shortage - and the summon thing. I'm not really convinced it's that different from a standard campaign to be honest. I've always found time limits within plots to be a handy tool for keeping things moving, so the PCs are usually fairly limited in what they can pick up extra to help them with a particular task. It's more the lack of the post mission shopping trip, that will increasingly hamper them as they level up. Basically I'd rather fix the problem with PCs being dependent on gear for their power than just using this campaign as an excuse to take away their stuff. The developers seem to want to play AD&D - and are bitter that fighters were really dull in AD&D and that wizards were the coolest. I played AD&D but honestly 3.5 is much more interesting. If it's going to be a combat heavy campaign, I'd much rather do it as a fantasy SWAT team with tactics and battlefield control to keep things interesting. Getting rid of the dice-rolling slugfest of yesteryear was one of the big improvements in 3.5 and I do not share the developers rose-tinted vision of the past in any way.
Also, could someone's who's read the whole thing point towards the bit with the more plot stuff please? I get the impression there's meant to be some interactions between the areas that's relevant, although not exactly a plot as such.
I'm currently leaning towards some really badass wizards wanting reagents (magical components), and basically the PCs are being sent on a hunting mission, and will get regular messages on what to hunt next. I'm not really sure I'll stick with the PCs being affected by prison side of things so much, I might give them a limited immunity of some sort - with of course interesting reactions from the natives if they find out. But I have other options - and it certainly needs some of plot to keep my players interested.
Sorry about the mega-post - but please give me any suggestions you have for making in more interesting.