From publisher blurb:
While many other Djorde books are descriptive of the setting, this book instead provides supplemental rules (compatible with 5e and potentially other systems as well) that you may use in your own campaign. These rule supplements are primarily written for Gamemasters (GMs), but with your GM's permission, players may read them, too. Each of these supplements are meant to expand the stories you can tell within the Djorde setting, providing mechanical rules to guide Djorde's novel themes.
This book contains 24 new subclasses for the 5e system, compatible with core classes such as barbarians, druids, and clerics. These subclasses are designed for the Djorde setting, a gilded age of technology, magic, and adventure. Within these pages, you'll find a medusa warlock, a haunted bard, a deva-blessed ranger, and a gunslinger rogue.