You can gain this ability at any time when creating your character or leveling up, so long as you meet its prerequisites.
You gain the ability to cast Spells, Techniques, and Rituals.
You gain +1 free rank of the Elemental Affinity Feat.
Spells you cast are always Runic Magic.
You use the higher of your Intelligence or Wisdom for your spellcasting attribute.
Runic Magic spells use Somatic components for their casting and Verbal components for their Metamagics.