Guys
Excellent points all. A few replies of my own to some of them :-
1) (To Klaus)
Thanks for the pointers on the mechanics of Shapechange.
- I agree that the spell lasts 3 hours. I think this is excessive.
- I agree that you gain Su and Ex abilities (but not SLAs). Also, you lose your original Su abilities. Trouble is, a Pitfiend has loads of Su abilities and my party's Sorcerer has none, so he sees that as a good deal.
- Most of the monsters in my module are evil and don't weild Bane (Evil Outsider) weapons, so this isn't a deterrent. Issuing most of the monsters with these weapons feels a bit artificial to me.
- Unfortunately, in our last two adventure, the big baddie was a Pit Fiend, so the Sorcerer is pretty familiar with them.
- Our Sorcerer (like most) keeps his material components in a belt pouch. The Alter Self spell states that equipment "remains worn by the new form (if it is capable of wearing the item)". I see no reason why a Pitfiend can't wear a belt
- I agree, Shapechange is dispellable, but against an 18th level caster, this isn't easy and the Sorcerer will have more Shapechanges to cast.
- I'd much rather have Meter Swarms cast at my baddies than fhave them fight a Shapechanged Sorcerer. I don't think I'm going to much use of Wish from my PCs because of the XP loss.
2) (To Campbell)
Thanks for the info on Alter Self and Polymorph. I actually consider myself a bit of a rules expert (here's you chance to make me regret saying that

), and disagree with one of the conclusions you draw.
Alter Self specifically states "your hit points remain the same", so we agree there. However, Polymorph (which supercedes Alter Self) then states "The subject gains the constitution scores of the new form". My party's sorcerer has a Con of 16. However, a Pitfiend has a Con of 27. This will then grant the Sorcerer and additional 5*18 hitpoints = 90 hit points. Hence the reason for the Sorcerer now having approx 200 hp as I stated in my first post.
I agree that BAB and Base Saves are not affected (but actual Fort Saves are due to change in Con). This is why I quoted the Sorcerer "only" having an attack bonus of +20 with his claws (a real Pitfiend has +30). Incidentally, a real Pitfiend has the multiattack feat, the sorcerer doesn't hence his secondary attacks are all at + 15 as compared to a real Pitfiend who has +28).
Interesting point about use of poison and the Evil subtype. However, our Sorcerer is L/N and worships Wee Jas who also has LE worshipers. I can't see that (disfavour from the deity) being much of a deterrent in this case.
3) (To WayneLigon)
The big baddie at the end will almost certainly use AntiMagic shell. However, there is a limit to how many of your baddies can use this spell. I hope for much of the adventure to be competitive, not just the last room.
4) (To Michael Morris)
Pitfiends are 18 hit dice, so perfectly legal (as well as familar).
5) (To Tessarael)
If the campaign were wholly mine I might consider banning Shapechange (or houseruling it to a duration of 1 round/level). However, I play in a group of 8 where all of us DM occasionally (although the bulk of the DM'ing falls to three of us). We tend to opt for majority vote after much e-mail discussion. I am really using this thread to gather info and opinions before I start that debate.
6) (To Raylis)
Why can't a Pitfiend wear rings and bracers? In the same (official WoTC) module I am going to run there is a Dragon wearing a ring and a Balor wearing a belt of Giant Strength.
Anyway guys, thanks for your thoughts. I'd appreciate more, especially ideas on how to prevent 60% of my dungeon succumbing to a DC27 will save against Fear Aura.
Frank