Let's say my alienist casts fiendform...

[Olive]

Here's three different rulings. Choose the one you prefer.

1. Pseudonatural summons affect the Summon Monster spells. Fiendform isn't one. (This is, I think, the official ruling.

1. 
   
   This makes sense.
   
   

   [*]The alienist turns into a pseudonatural version of the summoned fiend, as a result of his twisted connection to the Far Realms. (Powerful, but flavorful, and rather cool. I'd be tempted to use it.)

   
   But would this be unbalancing?
   
   

   [*]Pseudonatural summons do affect fiendform, however, the combo don't work because pseudonatural fiends are not fiends. Therefore, the alienist is unable to use fiendform, he lost the capability to draw upon fiendish powers.

This, I don't quite get. What would happen?

 

[Black Knight Irios]

If I had the book at hand at the moment I could probably answer your questions better, but let's see.

Normal rules don't allow transformation into a templated creature, even the most powerful one does not, because of balance issues.

The PC we are talking about is an exception of the rules, maybe you could allow to transform yourself into a pseudonatural-fiend with the fiendform spell, but again we have to think about balancing factors. I think I wouldn't allow it.

 

[Gez]

But would this be unbalancing?

Who cares? Probably. The fiendform spell borders on overpower already (even despite the errata reducing it to SM5 max). But though balance is important for the designers, it's less of an issue for gamers, because the DM can adjust things to his group better than a book can. As a DM, you can come up with additional prices if you think the asset is too great. Like insanity rules... Even if you don't have UA or CoC. How about, "Everytime you assume the total form of a pseudonatural entity, your body, mind, and soul are more and more shattered by the alien concepts of the Far Realms. In other words, everytime, you must make a Will save (DC 10+half the pseudonatural fiend's HD+its CR) or gets a permanent, definitive -1 penalty on all Fort and Will saves."

See?

 

[frankthedm]

good idea Gez. that sort of thing needs to show up more in D20.

The psudo-template is not that strong, the engery resists are inferior [acid electricity.] IMO to fiendish template [fire cold] and the one piont penaty to attack rolls ain't major, the DR and SR are same as the other templates IIR.

TBH the resistances should be different for each thing the template gets applied to. The creature from "the dunwich horror" had at least fire resistance. And Lightning guns were effective against the partially material flying polyps

 

[frankthedm]

My mistake, the SR is 10 plus HD, better than the other templates.