Improved Familiar Levels

[Sapper Woody]

This is more a question of curiosity rather than necessity. But Rein has the Improved Familiar feat, and his faerie dragon is level 15. He is a STR-based gish build (10Wiz/10EK/10DS).

My question, is if I end up going full caster, will that affect the familiar's level, or is that based purely on CL?

[Valefort]

Based on CL.

[Tsidkenu]

Actually, I thought Familiar HD was based solely on spellcasting base class levels, ie. Sorcerer or Wizard levels only. PRCs do not offer improvement to familiars.

A 30 wizard will have a much stronger familiar than a 10 wiz/ 10 EK/ 10 DS.

[Valefort]

It used to the case but was changed to be based on CL (or rather the number of levels giving spellcasting progression, spell power and practiced spellcaster are not taken into account).

[MrPsion]

Thanks for pointing this out, I always assumed it would be base class and so I figured I'd never take this feat

[Sapper Woody]

It used to the case but was changed to be based on CL (or rather the number of levels giving spellcasting progression, spell power and practiced spellcaster are not taken into account).

Now I'm curious as to the actual progression, then. My 10wiz/10ek/10ds has a base CL of 25 (practiced for 29). His faerie dragon familiar is level 15. Based on that information alone, it would seem that the familiar progression is 3/5 caster progression, meaning a 30CL (natural) would have a familiar at level 18. Is this right?