What are your tips for running a low or no-prep game?
The older I get, the less I find that I want to prepare for games. Between the responsibilities of writing professionally, working a full-time job (well, hopefully shortly), and maintaining a house, the idea of running a high-prep, high maintenance game simply no longer appeals. It's why I do most of GMing extemporaneously, using some of the utilities I mentioned earlier.
But, if you're going to skip on your campaign prep, there are numerous ways to make your life easier. Firstly--and I can't stress this one enough--pick a system that emphasizes light prep and that you know particularly well. Systems like Savage Worlds and ICONS work well for me, as NPCs can primarily be made up on the fly. Is he a big, burly fighter? Give him a d8 or a d10 in Fighting and you're good to go. While modern game design has emphasized unified mathematical systems (which typically feature, at least, verisimilitude), a system like d20 or Pathfinder simply doesn't have that flexibility, with its emphasis on numerous bonuses and fiddly modifiers. If you're comfortable with a mechanical system, you'll start finding those patterns in the numbers that will let you make up an NPC's stats without even writing a thing down.
|Let 'em play in the sandbox for a while!|
Lastly, get used to saying "Yes". While it's easy for a GM to shut down ideas or offer penalties, it's often in that same GM's interest to instead let the players come up with creative ideas on their own, then simply going with the flow on those players' ideas. Let your players surprise you--their creativity is just as valid as your own!