So some of you might have noticed the term "Iron GM" in my Seasons of Doctor Who as an RPG Campaign postings and you might have wondered what I was on about. Well, let me explain, and perhaps, inspire.
Iron GM that does the same thing, live, with 5-hour games immediately following a single hour of preparation. The 2011 Iron GM, for example, forced GameMasters to work in Ogre Magi, an opera house and oppression. Not too hard from where I'm sitting. Pyramid's Iron Ref were a little more random, if I remember correctly - a Stradivarius, a rabbit's foot, Mexico - and then turned into an Espionage, Horror and perhaps, a Western game.
But maybe not every member of the group is up to the challenges of GMing. That makes Iron GM a little more difficult, but not impossible. In fact, I've played Iron GM all by my lonesome. In my Dream Park games, I had the opportunity to create different GameMasters who "ran" the games for the "players" played by my players. It sounds very meta, but it was pretty simple in terms of execution. The players simply became used to the GMs and their different personalities and interests when it came to scenario-building. (Not everyone is playing Dream Park, so I wrote an article that discusses different ways of achieving the multi-GM effect in other games HERE.) Iron GM competitions in this context are all written by the same person, but written and run with a different GM personality in mind (varying genre was crucial). So for example, I once prepped three consecutive games that had the following ingredients: Cheating at sports, a temple, and a celebrity and/or Bob Gauvin (inside joke, he's a local actor with a strong personality we all knew). The games were the possessed football scenario and the luchadore adventure, both from Call of Cthulhu's Blood Brothers, and the DC Heroes module When a Stranger Calls (which starts with a superhuman basketball game). So you see? I was even able to use pre-fab adventures (with very few tweaks) and still respect the conceit.
Choosing ingredients can be done a number of ways. The best is probably to have all the players write down a few and draw three out of a hat. A lone GM could ask three different people in their lives to supply an ingredient each. Optionally, treat is as a friendly competition, with players rating each ingredient's use in any given game to see who (or which of your personalities) did the best with them.
It's not a bad way to get inspiration for games when you're not quite sure where to send the PCs next...