Trilogy - Adding Works To An Existing Trilogy

Adding Works To An Existing Trilogy

Creators of trilogies may later add more works. In such a case, the original three works may or may not keep the title "trilogy".

By contrast, The Foundation Series by Isaac Asimov originally consisted of Foundation, Foundation and Empire and Second Foundation and was considered a trilogy. Asimov wrote several more Foundation books and retroactively incorporated many of his other works into the continuity of the series. Despite this, the first three books are still considered a trilogy because they contain a story that is self-contained. Further complicating the matter, the Foundation series was originally eight short stories and novelettes written for science fiction magazines; its division into three books is more or less incidental.

The first three novels in The Hitchhiker's Guide to the Galaxy series were dubbed a trilogy, and even after he extended the series, author Douglas Adams continued to use the term for humorous effect - for example, calling Mostly Harmless "the fifth book in the increasingly inaccurately named trilogy."

The six Star Wars films are generally separated into two trilogies; the "original trilogy" (the three films released between 1977 and 1983) and the "prequel trilogy" (the three films released between 1999 and 2005, which take place before the original three films).