Incantrix

[Erts]

Well, as my plans to GISH fell apart, I was wondering how to do this PrC.
I know people say that it is HP, and thus doesn't need to worry about optimization, but my current DM seems to be the guy to push his players to the limit (in a good way .)

So, any builds or ways to make this work to its full potential?

[Private-Prinny]

Pick up Twin Spell, Maximize Spell, Split Ray, and Arcane Thesis (Enervation). If you want, pick up Easy Metamagic (Twin Spell). With 10 levels of Incantatrix, that 1d4 negative levels from a 4th level spell becomes 16 negative levels from a 7th level spell. If you toss Empower on there, it becomes 16+(4d4/2) negative levels (average 21) from an 8th level slot.

Insta-kill pretty much anything non-epic that's vulnerable to level drain at level 15. And that's when you're not trying to overly break it. Incantatrix is just that good.

[Erts]

What school would be best for specialization?

[Private-Prinny]

Conjuration and Transmutation are generally considered the best. If you're going Incantatrix, I would stay away from Focused Specialist, because that extra school hurts you a lot.

As for prohibited schools, I would start with Evocation and Enchantment, PrC around a bit before entering Incantatrix, so you can get 4th level spells, nabbing Enervation (make sure you pick up Shivering Touch before then) at level 7, and enter Incantatrix at level 8, banning Necromancy.

[Douglas]

Boost your spellcraft check through the roof, get access to Body Outside Body (Wu Jen spell from Complete Arcane) somehow (such as duplicating it with Miracle from Arcane Disciple (Luck), or you could just actually be a Wu Jen, but their spell list sucks compared to Wizard), and go to town applying Persistent Spell to all sorts of buffs with Cooperative Metamagic and Metamagic Effect.

Expect a thorough DM smackdown and banhammer if you take this to its full potential, though (see the Team Solars link in my sig).

[Erts]

Okay, I'm doing Wizard 5/Incantrix 10/ ??? What do you think I should go for the remaining 5 levels?

[sambo.]

Okay, I'm doing Wizard 5/Incantrix 10/ ??? What do you think I should go for the remaining 5 levels?

Archmage?

As for prohibited schools, I would start with Evocation and Enchantment, PrC around a bit before entering Incantatrix, so you can get 4th level spells, nabbing Enervation (make sure you pick up Shivering Touch before then) at level 7, and enter Incantatrix at level 8, banning Necromancy.

that's a good trick.