It all basically started in 1974, when Gary Gygax and David Arneson published three little brown booklets that formed the first set of rules for Dungeons & Dragons. In a departure from the board games and wargames available at the time, most of the "action" in D&D took place in the minds of the players. The players took on the personalities of fantasy-themed adventurers, who live their lives through a combination of imagination, narrating what they intend to do, and rolling dice to see what happens. In other words,
"You play Conan, I play Gandalf. We team up to fight Dracula."
The imagined characters could be as fleshed-out or as simple as desired by the players. For players who didn't want to turn the game into full-on "improv theater," there were many hard-and-fast rules for things like combat, magic, and feats of acrobatic dexterity, so that one could figure out what happens to one's character relatively easily. Many characters began their "lives" as weak and inexperienced schlubs, but as they spent time adventuring -- battling foes, exploring new lands, and winning treasure -- their abilities could increase. If they survived, that is!
One of the players, called the Dungeon Master (DM), was set apart from the others by being in charge of the world inhabited by the other characters. The DM was a kind of "referee" who had the final decision about the actions that occur in this imagined world. The DM also played the roles of everyone that interacts with the characters, including friends, foes, innocent bystanders, animals, spirits, or fantastical creatures.
The original rules for D&D published in the 1970s and early 1980s were often not all that complete. (A complete mess, some would say!) Thus, many DMs and players had to improvise and create "house rules." In fact, many of the successor RPGs that came out after the late 1970s began as homebrewed attempts to fill in the gaps (or fix the problems) of D&D.
As time went on, and the initial pop-culture fad of D&D faded, the remaining "serious" players demanded more completeness and rationality in their RPGs. In my opinion, the 2nd, 3rd, and 4th editions of D&D became more optimized for the "power gamers" who cared more about besting one another with their encyclopedic knowledge of the rules than about immersing oneself in an imagined otherworldly situation. The most recent (4th) edition of D&D seems to be very much about having one's character gain power rapidly through a series of pre-programmed battles and challenges. I may be looking at the past with rose-colored glasses, but this seems very different from the more free-wheeling way the game was played back in the day.
(Of course, I must include a disclaimer about FUN. If you're having it, no matter what rules you're playing by, it's fine with me!)
Over the past few years, the Internet has allowed like-minded oldsters like myself to reconnect with the hobby and find out that it's still possible to play the way we like. Two quasi-manifestos that sound the call for the Old School are available here and here. The blogosphere is full of fascinating people who publish tons of free gaming material and inspiring slices of gaming life. I'd be remiss without mentioning Jeff Rients, James Maliszewski, Zak Sabbath, Alexis, and James Raggi. For more, click on my profile to see other blogs that I follow, and keep going to the other blogs linked by them as well.
Anyway, I'm having a great deal of escapist fun thinking about RPGs these days. To tell the truth, I'm NOT really looking to start playing again! I had great fun with my friends throughout the entire decade of the 1980s playing D&D and other games. However, I was never one to seek out strangers to play with, just to play. I'm designing a new RPG solely for the fun of it, and for no other reason. If someone else is inspired by even a small piece of it, that's icing on the cake!