Released from the constraints of the real world, video role-playing games have taken on a whole new design of their own. Video RPGs have tended to show some significant differences from others, usually blending into adventures, typically with a single party on a definite quest.
Text RPGs evolved from text adventures, and including some titles still played today, such as Nethack and the various MUD-like things. Among the first computer was Akalabeth (1978), which gave rise to the well-known Ultima series. RPGs appeared on consoles somewhat later, starting with the NES titles Dragon Quest (1986) and Final Fantasy (1987). The latter, made by Square, is still one of the most prevalent titles today.
Fairly recently more and more multiplayer RPGs have appeared. For instance, Diablo features a system by which different players can enter the same world and cooperate against the enemies, trade equipment, or should they wish, kill one another. Massively multiplayer games, huge open-ended worlds with hundreds of interacting characters, have also appeared, pioneered by systems like Ultima online and Everquest.
An interesting entry into the RPG world is Pokemon, a fairly simplistic game whose main innovation was the replacement of the party by creatures that can be captured, collected, and trained. Its success is unqualified, leading to a huge industry with many spin-off products, including other games, cartoons, and endless merchandise.
The most popular company in America in the RPG business is a Japanese company by the name of Squaresoft. Essentially Squaresoft started the turn-based fighting RPG genre with their amazing game FINAL FANTASY. The first game...although a bit crude in the graphics sense, had great gameplay and an interesting storyline. One of the great things about squaresoft is in fact the storylines that they produce in their Final Fantasy games. There are at least 10 (perhaps 11) Final Fantasy games out on today spanning such systems as Nintendo, Super Nintendo, Playstation, Playstation 2, PC... and perhaps the Xbox. But each game they produce has a different storyline.
In Japan, however, Enix's Dragon Quest series outstrips Final Fantasy in both sales and popularity, at least in Japan. Released in the US under the name Dragon Warrior, the Dragon Quest Series has always had a medieval setting. The first three games had a connected story line (chronologically, 3, 1, 2), but Enix decided to make new installments to the series distinct starting with Dragon Quest IV. (Someone please add more background info). The popularity of the series in Japan is so great, in fact, that many schools give students the day off from school when a new installment comes out.