For purposes of play, Pathfinder core material, and approved Pathfinder resources are available for application. If you want to use something from a non-approves sourcebook, it needs DM clearance.
Following is a list of alternate/supplemental rules which are considered “house” for anyone playing in a Caracarn campaign.
The only rule that matters: THE DM IS ALWAYS RIGHT! If I'm proved wrong, I'll happily admit it. If you want to challenge me in game though, be prepared to face the consequences. If done in combat, be prepared to lose the next die of fate rounds of action (You will not be considered flatfooted, but you will be zombified; unable to react, use any skills, feats, or take any actions whatsoever).
If legalese comes up in a non combat-round situation, arbitration/research may or may not face sanctions on an incorrect challenge. Roleplay will almost ALWAYS get you past where the dice cannot in non-combat situs (and sometimes in them)!