Original Series (PS franchise)
With the release of Phantasy Star in 1987, Sega launched a series of classic turn-based RPGs across the Master System, Genesis, and Game Gear, which helped define a generation of games. This franchise is best characterized by the millennium-spanning multi-generational battles against the malevolent Dark Force, spanning four numbered games and several "gaiden" side stories. PS ranks highly among all gaming franchises for the number of compilations, re-released ports, and remakes that the original four games have received.
After laying dormant throughout the Saturn/Playstation era which saw a renewed interest in Japanese RPGs amongst Western gamers, Sega re-booted the series with Phantasy Star Online on the Dreamcast. A 3D action RPG with online and offline play, PSO was worlds apart from its 8 bit predecessors, but became a hit, spawning three additional episodes across the Dreamcast, Gamecube, PC, and Xbox.
In December 2008, Phantasy Star Zero, the first new PSO game since 2005, was released on the Nintendo DS.
In 2006, with PSO service nearing shutdown, Sonic Team launched Phantasy Star Universe, a second reboot of the series. With a new universe to explore, along with a large number of gameplay changes PSU was, despite similarities, a large departure from PSO.
In July 2008, Sega released Phantasy Star Portable, which took PSU's gameplay and gave it a new storyline set between PSU's first two chapters.