To unlock the skill line, speak with Loremaster Celarus after completing the first quest in the Summerset main story, “The Queen’s Decree.” He’ll task you with completing your first quest for the Psijic Order. This earns you access to the Psijic Order skill line.
Once you unlock the skill line, you can access it the same way you access the Mages Guild and Fighters Guild skill lines. Open your Skills menu and select Guild. From here, everything functions exactly like you’d expect it to.
You’ll unlock a new skill for nearly every rank and you’ll level up your rank for every Psijic Order quest you complete. The following section breaks down every skill you’ll unlock at each rank.