Help understanding Practiced Spellcaster Ultimate Magus trick

[IIzak]

I don't know if its just a block or what, but no matter what way I think about it, this trick doesn't make sense in my head. Essentially, I want to play either a human or Illumian Beguiler 1/ Wizard 4/ Ultimate Magus 10/ +X 5 and taking Practiced Spellcaster: Beguiler, at lvl 3ish. I don't understand how the +4 CL keeps your beguiler level above/equal to your wizard CL for the entire progression of Ultimate Magus. I think I just need someone to spell it out for me how this works as far as the CL increase and how it interacts with HD and basically just break down the trick for me step by step. I'd really appreciate it.

[Dread_Head]

It doesn't keep it above your wizard level for the entire progression, just for the first two times you have to choose the lowest. It means you only lose one Wizard caster level during Ultimate Magus (and one before) rather than losing three during the class. I believe with the right Illumian tricks you can get Ultimate Magus to progress Wizard at every level but I'm not familiar with exactly how.

Edit: Before you take the first level of UM your caster level for Beguiler (With Practised Spellcaster) will be 5 and your Wizard CL will be 4 so at the first level you increase Wizard casting by one. Then the next two levels increase both Wizard and Beguiler. At UM 4 your Wizard and Beguiler CLs are equal so you can choose which to advance (pick Wizard). And then the next two levels advance both Wizard & Beguiler until 7 when you lose your first Wizard CL as it is now higher than Beguiler. The last three levels will progress both.

[Biffoniacus_Furiou]

At 1st, 4th, and 7th level, you gain new spells per day and
an increase in caster level (and spells known, if applicable) as
if you had also gained a level in your arcane spellcasting class
with the lowest caster level....
If all your arcane spellcasting classes have equal
caster levels, you can apply this benefit to any of your existing
arcane spellcasting classes. You do not, however, gain any other
benefit a character of those classes would have gained.


Without Illumian:
A Beguiler 1/ Wizard 4 with Practiced Spellcaster: Beguiler has a caster level of 5th for Beguiler, 4th for Wizard, so UM 1 advances Wizard.
A Beguiler 1/ Wizard 4/ UM 3 with Practiced Spellcaster: Beguiler has a caster level of 8th for Beguiler, 7th for Wizard, so UM 4 advances Wizard.
A Beguiler 1/ Wizard 4/ UM 6 with Practiced Spellcaster: Beguiler has a caster level of 11th for Beguiler, 12th for Wizard, so UM 7 advances Beguiler.

With Illumian and the Krau sigil:
Beguiler 1/ Wizard 4 with Practiced Spellcaster: Beguiler has a caster level of 5th for Beguiler, 5th for Wizard, so UM 1 advances whichever you choose: Wizard.
Beguiler 1/ Wizard 4/ UM 3 with Practiced Spellcaster: Beguiler has a caster level of 9th for Beguiler, 9th for Wizard, so UM 4 advances whichever you choose: Wizard.
Beguiler 1/ Wizard 4/ UM 6 with Practiced Spellcaster: Beguiler has a caster level of 13th for Beguiler, 13th for Wizard, so UM 7 advances whichever you choose: Wizard.

Note that each of those applies Arcane Spell Power from UM after Practiced Spellcaster and Krau, as that one can increase their caster level above their character level.

Edit: If not using Illumian, you can go Beguiler 2/ Wizard 3/ UM 10 and apply all ten UM levels toward Wizard. You still end up at 13/15 Wizard and 9/15 Beguiler, but you get 2nd level Beguiler spell slots at 8th level instead of 10th level. Plus if your second Beguiler level is after the Wizard levels you can catch up some of your skills due to the higher base skill points it gives.

Edit 2: You can also go Beguiler 1/ Spellthief 1/ Wizard 3/ UM 10 with Master Spellthief and apply all ten UM levels toward Wizard, plus you'll have an inflated caster level later on (15 for each class at level 10, 26 at level 15).