Seems like every game is an RPG these days. At this point we fully expect the next chapter of Tetris to tout "RPG elements!" on the box. It's the cliché of our times. But saying something has been inspired by RPGs usually means more than "it has numbers and a skill tree." Just about anything with even a whiff of RPG about it can trace its roots back to Dungeons & Dragons, the tabletop adventure that debuted back in the '70s.
Perhaps the greatest contribution D&D made to gaming wasn't just the use of numbers and random rolls to determine success and strength, but rather the definition of, well, roles. D&D laid down the basis for the character archetypes that appear in nearly every modern game, especially anything that even vaguely resembles an RPG. And, as it turns out, just about everything breaks down to one of three character types: The warrior, the wizard, and the thief. Or to put it into proper D&D 1st Edition terms, the Fighter, the Magic-User, and the Rogue.