(Feat) Theurgic Advancement

[Xzoltar]

THEURGIC ADVANCEMENT [Multiclass]
Requirement: Practiced Spellcaster ; Must have at least 2 level in a Prestige Class that increase your spellcaster level
Benefits: For every two +1 level of existing spellcasting class you gain you can gain a virtual level in the class that provide your spellcasting power. You can take this feat more than once each time applying to a different class.

Example: A Wizard 5 / Fighter 2 / Eldritch Knight 10 / Archmage 3 with feat Practiced Spellcaster (Wizard) and Theurgic Advancement (Wizard) will have the Wizard Spellcasting of a 17th level wizard (Caster level 20) and he will gain 1 Extra Wizard Feat and is Familiar will increase to lvl 11 from his +6 virtual wizard level.

Very very bard wording here, but just a idea I had, was going to go to ask for something like that in Ask a Homebrew but got a idea as typing my request.

I could also change the feat to apply to other class as well and not jsut Spellcasting. so if we take the same example and the character also take Practice Combattant (Fighter) and Theurgic Advancement (Fighter) he will gain +5 virtual level from Eldrtich Knight but none from Archmage as it dosent advance is fighting prowess. So he will gain +2 Extra Fighter feats and is Fighter level is considered to be 11 (lvl 2 + 5 virtual lvl +4 practiced combattant) for taking Fighter feats.

Thoughts ?

[eftexar]

Alright forgive me ahead of time for correcting stuff you might not have said. But your wording for what you wanted to do was sort of funky.

It seem pretty powerful. As it is classes that grant two sets of spellcasting really boost your abilities already. If you then grant half of those as full levels, well... I think you can see the problem with some prestige classes. You might be better off granting an ability that allows the caster levels from two unrelated casting classes to stack.

And while I think non-casting core class need all the help they can get, coupling these into one ability is too powerful. You would probably have to make a separate feat for each class though, because without being specific you could stack several classes and break the system. Additionally I wouldn't base this off of +? of spellcasting and might set it up to work on some other chasis (not sure what though).
It might also need to work in specifically increasing one ability from each class that progresses (like the bonus feats you have listed, sneak attack damage, etc), such as "every even level of -insert class- treats you as if you were a fighter of 2 levels higher for the purpose of the number of bonus feats you have and for qualifying for other feats and prestige classes" or "every even level of -insert class- treats you as if you were a rogue of 2 levels higher for the purpose how much damage your sneak attack deals."

edit- relooking at you wording, I suppose that's sort of what you intendeded for the non-casting abilities