Star Trek IV Sourcebook Update is a supplement for the Star Trek Role-Playing which was published by FASA. The book includes information about alien races such as Alpha Centaurans, Andorians, Arcadians, Ariolo, Arkenites, Bzzit Khaht, Caitians, Deltans, Edoans, Efrosians, Kasheeta, Tellarites, Vulcans, Xelatians, and Zaranites. The book also includes information about Star Trek politics, government, history, security procedures, and a timeline chart.