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Disciplines are Crowfall's “multi-classing” system. They allow you to customize/optimize/break your class in a number of amazing ways.

Disciplines are inventory objects that could be permanently equipped to your character, essentially granting the character a “subclass” with additional powers, skills, attributes, etc. In addition, these subclasses permitted access to unique armor and weapons. 

Players can equip 2 Major Disciplines (either combat or harvesting), 3 Minor Disciplines, and 1 Weapon Discipline.

as of Pre-Alpha 5.4, there are about 100 Disciplines divided in: