Despite there have been already some discussion about prestige classes.Unfortunately I did not follow them in detail.
Is it possible to use 3.5 PrCs in the Pathfinder game (apart from the PrC conversion classes)?
Did anyone tested it? Does it make sense?
Up to which number of PrCs is it playable?
What does one need for a conversion? Only skill conversion? Or also the feats/levels etc.
Thanks for help.
Technically all you have to do for converting 3.5 PrC's (besides the DMG ones, which can be considered 'converted') is double-check feat requirements (to make sure about anything that was changed), reduce skill rank requirements by 3 (to reflect PFRPG's skill system) and you've set the requirements.
The PrC itself only requires the skills list be updated and the BAB adjusted to match up to the HD of the class (or vice versa). This is the sticky part, as some PrCs do not match up so well 'by default' - you will have to judgement call this one.
Any PrC that is not open license I do not believe will ever see an official conversion to Pathfinder.
The web enhancement released for Pathfinder prestige classes also contains the current rules for performing such conversions for your own campaign.
Remember also to change the Save progression from 3.5 Prestige Classes to PFRPG Prestige classes:
In 3.5 (and PFPRG Core Classes ONLY):
Good save progression is 1°)+2, 2°)+3, 3°)+3, 4°)+4 and so on (basically, level/2 +2)
Bad save progression is 1°)0, 2°)0, 3°)+1, 4°)+1 and so on
(basically, level/3)
In PFRPG (Prestige Classes ONLY):
Good save progression is 1°)+1, 2°)+1, 3°)+2, 4°)+2 and so on (basically, (level-1)/2 +1 )
Bad save progression is 1°)0, 2°)+1, 3°)+1, 4°)+1 and so on (basically, (level+1)/3)
The only prestige classes that I've heard complaints about are ones that are focused on mechanics that have been radically changed, like barbarian rage, turning undead, or clerical domains. Those ones will almost certainly require some retooling.