From the back of the book and Troll Lord Games website:
Beyond the next horizon lies the uncharted future where science and fiction merge, a line beyond which lies a stellar wilderness defined by our own imagination. StarSIEGE Event Horizon is a science fiction role playing game whose unique design allows you to set the tone and mood of the game. With this rules set you can play gritty, realistic sci fi or range out to the epic space operas or pulp serials of screen and television. StarSIEGE Event Horizon is your toolkit for bringing worlds of fantastic science and adventure to life.
These Quick Start Rules are designed to give you a quick look into the future of role plaing. Utilizing the simply elegant Siege Engine Josh Chewning has scripted a game that is at once easy to learn and fast to play.