> That is why so called derivative works are allowed (and even encouraged). Derivative works are not given a free pass from the normal constraints of copyright

> That is why so called derivative works are allowed (and even encouraged). Derivative works are not given a free pass from the normal constraints of copyright. You cannot legally publish books in the universe of A Song of Ice and Fire without permission from the author (and often publisher), calling them “derivative works.” It’s why fan fiction is such a gray area for copyright and why some publishers have historically squashed it hard. The exceptions for this are typically fair use, which requires multi-factor analysis by the judiciary and is typically decided on a case-by-case basis.