Sigil Prep came from a brainstorming session. I hadn't run a game in a while, and I wanted to come up with a new setting. (My last game, a modern-day D&D game set in Miami, Florida, lasted from the day the 3e Player's Handbook came out, until just before the 3.5 books were released. Good times. Ask me about it some day.)
The modern day thing had worked for me, but I didn't want to recreate the same thing again. I spent several days creating a version of the Forgotten Realms setting, with modern technology and government structures, and planned to have the PC's be members of the Harpers, which in this setting, would be the Dalelands' equivalent to the CIA or MI-5.
One thing kept bugging me. Draconians. I wanted Draconians. Now, certainly, I could put Draconians in the game and not worry overmuch about it. But something in the back of my head made me wonder: Could I conceivably create a setting that would incorporate everything, for every book. Not just every race, or class, or feat, or spell, but every Outer Plane, every god, every organization and culture.
Of course not. That would be stupid. But I wondered how much I could get away with. At first, I tried a take-off of Spelljammer, without the crystal spheres and phlogestum, where you actually traveled in space, and each race of elf or dwarf or goblin was the native form of a different planet. But the more I tinkered with it, the less I liked what I was doing. I was either stealing too many ideas from my friend David, who had just run a space-travel game I was in, or I couldn't decide about planets (should the nations of Grayhawk and Faerun and Krynn be planets, or should I just wholesale create new planets for each race?)
With Spelljammer not working out, I thought, "Well, the only other setting that ever incorporated all other settings was Planescape." Planescape, sadly, came out after I had given up D&D, and before I took it up again with 3e, so I only knew a few basics. Such as the City of Sigil. So what would be going on in Sigil that would be unique? The idea came to me while I was looking at DVD covers (I work at a video store): American Pie, Porky's, Animal House, Fast Times at Ridgemont High. Was it playable? Who knows? But I decided to see what I could do with the idea. Of course, the inspiration had to expand from school-high-jinks sources, to supernatural school-high-jinks sources: Buffy the Vampire Slayer, Harry Potter, various Japanese anime stuff.
When I finished the first few bits of flavor text, I immediately posted on the boards at the WotC site ( www.wizards.com ), and immediately got tons of feedback, every bit of it positive. I put up this web site within the month. Still didn't have a gaming group, though, as most of my Miami group moved, or had Real Life affairs that prevented regular gaming.
Then, of course, one of the regulars at the WotC boards suggested that I start a message board game, and the fruits of this are now at www.plothook.net . (Still looking for a live game, though).
OTHER WEB SITES OF INTEREST
D&D related: