This category is for series of anthologies in science fiction or one of its subgenres. There are two types:
Or
Single fictional universe series are usually created as the proprietary work of a single author (e.g. Larry Niven's Known Space tales) in which other writers are invited or desire to write a story within, and which spin-offs, if they become a series instead of a single work, are considered a sub-series:
(See also Category:Science fiction anthologies, and Category:Science fiction short story collections for single book and single author collections respectively.)