In general, it would be seen as derivative work.
In copyright law, a derivative work is an expressive creation that includes major copyright-protected elements of an original, previously created first work (the underlying work). The derivative work becomes a second, separate work independent in form from the first. The transformation, modification or adaptation of the work must be substantial and bear its author's personality to be original and thus protected by copyright. Translations, cinematic adaptations and musical arrangements are common types of derivative works.
Still requiring permission from the copyright holder.
For copyright protection to attach to a later, allegedly derivative work, it must display some originality of its own. It cannot be a rote, uncreative variation on the earlier, underlying work. The latter work must contain sufficient new expression, over and above that embodied in the earlier work for the latter work to satisfy copyright law’s requirement of originality.
A mere outline of copyrighted work would probably not qualify as "substantial original content". -- But I am not an attorney.