From publisher blurb: The 21st century has cracked open the past and future–not historical periods, true, but really deep time. Dinosaurs are a day trip away on a fast ship and your potential stomping grounds range over billions of years. Pit yourself against a future slave-running Empire, trade between human colonies, or just explore a nearly infinite progression of Earths that get ever-more alien as you get farther away from home. Empire of Time is an OSR SF RPG using the free Cepheus Engine core rules or other similar game systems. Play as humans from the 21st century, or from the future, or even one of four different races evolved to intelligence long after we are gone. Includes maps and descriptions of Earth throughout geological time (past and future) based on current scientific discoveries, adventure seeds, organizations to use as patrons and villains, a bestiary of creatures from the most ancient times to hundreds of millions of years from now, and much more.