You can add some caster levels together for different spellcasting classes you possess.
Prerequisites: Levels in at least two spellcasting classes.
Benefit: You can add your caster level from one class to your caster level in another for spells cast from that class. You cannot add more levels than the lower of the two spellcasting classes you have. You can add caster levels from divine and arcane classes, so long as you stay within the above limitation.
For example, if you are a Druid 3/Wizard1, you can take this feat to allow you to add 1 to your caster level as a Wizard. You cannot add all 3 levels of Druid because you are limited by the lower-level Wizard class.
Normal: You can’t add caster levels from two different spellcasting classes.
This comes from Ben Lesel, who’s a player in my campaign The Great Escape. It’s a feat meant to help out those low-level folks in a world where Mystic Theurge may or may not exist.
I know all about Practiced Spellcaster and I don’t personally find that feat to my taste. It’s extraordinarily boring and feels very forced. Practiced Spellcaster is broken at low levels and becomes gradually more worthless as you go up. Ben’s version, which I’ve rewritten and called Adept Spellcaster, scales in a way that seems much smoother to me.