As far as video games are concerned, however, the definition runs a little deeper. Electronic RPGs often subscribe to a set of characteristics that include, but aren't limited to, an engaging story, a menu-driven battle system, a large cast of interchangeable characters to play with, and some kind of character-growth system that lets your characters become stronger as you progress deeper into the game.
That's still an incredibly broad definition of the term, as RPGs have shifted, evolved, and acquired new characteristics over the years.
Some of the earliest electronic RPGs to feature a graphical interface include Ultima I: The First Age of Darkness (first released in 1981 for the Apple ][, Commodore 64, and DOS, among other computers available at the time), and Wizardry (also released in 1981 for various computers that were popular at the time). Inspired, Japanese developers worked on role-playing games that utilized simpler game mechanics, but featured more impressive graphics and sound. Japan's earliest contributions to the role-playing genre through Famicom (NES) titles like Dragon Quest resulted in the birth of what's since been sub-categorized as the "Japanese role-playing game," or "JRPG."
It's worth noting that RPGs developed in the Western part of the world and JRPGs both derive core inspiration from early paper-based table-top RPGs like Dungeons & Dragons.
Early PC-based RPGs, and early console RPGs (the term "console" referring to game systems like the Nintendo, Sega Genesis, and handhelds like the Game Boy and Game Boy Advance) evolved differently. Whereas game studios based in the Americas and in Europe typically released their works on computers, consoles received many role-playing games that had initially been released in Japan, including games from the Final Fantasy, Dragon Quest, and Phantasy Star series. The massively popular Pokemon RPG series, which originated on the Game Boy, was likewise born in Japan.
The advent of the Internet and the maturation of the games industry has widened the audience for role-playing games, and Western and Eastern offerings are now popular worldwide. The increased availability of broadband internet connections has also resulted in the rising popularity of the "MMORPG" -- the "Massively Multiplayer Online Role-Playing Game." One example of an MMORPG is Blizzard's World of Warcraft.
Again, it's difficult to pin down an exact definition of the RPG genre (especially since it's not uncommon for games from other genres to incorporate RPG elements), but RPGs can be counted on for hours of exploration, enthralling stories, and deep gameplay. Some great Nintendo DS RPGs include Mario & Luigi: Bowser's Inside Story, Pokemon Black/White, Dragon Quest IX, and Final Fantasy IV.