I m playing as the Gorgon, who is a master-level mage. It's still a work-in-progress, but here is how it plays out in-game so far: If you are not a mage/sorcerer/priest yourself, you can give regency via a decision to your court priest/mage/sorcerer so that they can cast realm magic on your behalf Priests with a bloodline trait gain regency from their temple holdings You can build province level buildings called 'source holdings' to gain more regency, if you are a mage or a sorcerer or have a court mage/sorcerer (given via minor title) Tainted bloodline traits, will give 0.2 regency per month, while the greater bloodline traits give 0.8 Piety is now called 'Regency', which represents the amount of stored divine/rulership power in an individual Here's how the Realm Magic system works on a basic level: Due to many rulers having greater of lesser amounts of actual divine power flowing through their veins, they are capable of harnessing the power of the land that they rule to cast spells on a province-level, or even an entire region! They are also able to amplify the power of their combat spells, and summon free upkeep units. While permission has been granted to adapt the 0.1.4 magic system from Elderkings once they release 0.1.5, there is another type of magic in the Birthright setting which will have to be built from scratch: Realm Magic. Reposted from the main development thread on the CK II modding forum:

Crusader kings 2 middle earth project