Sourced from the Ruins & Rogues Adventurer’s Guidebook, 2nd Edition
Librarian Sub-Classes
At level 30 librarians earn their usual 1 skill point but also gain 100 hit points and an extra equipment slot. At this point they may also choose one of the following sub-classes:
Booksassin
Stealthy and deadly, the Booksassin moves as silently as a turned page and strikes as deeply and unexpectedly as a papercut. This sub-class focuses on speed, surprise, and damage at the expense of durability, legibility, and archival quality. Booksassins may use the Tome Travel ability once per day to travel through bookshelves as if casting a teleport spell of equivalent level and do automatic quintuple damage upon emerging from one.
Dewey Deathimal
The Dewey Deathimal classifies and shelves hard-hitting magical and quasi-magical attacks, casting them over a wide area like a shush quiets an unruly mob. This sub-class focuses on intelligence-based area of effect attack spells at the expense of granularity, adaptability, and clarity. Once per day, the Dewey Deathimal may use Books to Bats, which causes all nearby tomes to animate, flap through the air, and descend on all targets in a designated area bringing death from a thousand papercuts.
Bibliothief
As punishing as an overdue library book and as well-stocked as a private college library, the Bibliothief focuses on collection development at all costs. This grants major bonuses to the Acquisitions and Prestidigitation skills at the cost of Cataloging and Circulation. Bibliothieves can use the Bookwalk ability to walk across the tops of shelves and gain a bonus to all Book Acquisition rolls (which the sub-class can apply to any item with words on it, not just books).
Excerpts From Nonexistent Books 