And on a different note, if you're worried about the burdens of prep you might be interested in reading about
no myth style play, which combines player freedom with minimal GM prep.
Here is a link to a play report for a session I ran in a semi-"no myth" style.
Word of warning on this advice. Some players love 'no myth'. Others hate it. It's one of those topics that every seems to have an extreme opinion on. Personally, I'm in the 'hate it' camp, and I'd probably never play under a GM that tried 'no myth' on me ever again. I might not walk out on you, but I'd be tempted to and I'd pretty much consider it a betrayal of trust and cross you off my list of 'friends to game with'. The end.
Even the meaning of the term is a subject of debate. pemerton calls his session 'semi-no myth', but not only does make no sense to me (is that like being semi-pregnant?), because all games are 'semi-myth' in the sense that its impossible to have literally everything prepared so what is the difference between 'regular' and 'semi myth', but the session he calls semi-no myth on inspection seems really really far from a no myth set up (I might call it 'radically not no myth').
No myth is defined as follows: "The premise, and the reason it's called No Myth, is this: nothing you haven't said to the group exists."
Examining pemerton's scenario, we find the following:
a) There is something called the Nerathi Empire. It's presumably a published setting with a lot of canon that pemerton can draw on to flesh out the myth and history of his game.
b) The scenario is based off of a published adventure and thus contains lots of details to draw from.
c) Per his own account, pemerton did at least some preparation on top of using multiple premade sources.
d) Per his own account, pemerton's myth creation during the scenario was done on the basis of the preexisting myth of his campaign. In other words, pemerton has to know a bunch of stuff exists in order to even fill in the blanks.
When I read pemerton's scenario, I don't see ANYTHING that looks like "no myth". What I see is pemerton being a little bit more of a "say yes or roll the dice" sort of DM than he has apparently been in the past (when he ran RoleMaster, for example), in that he is giving the benefit of the doubt to any sort of player led creativity or investigative action and adding detail to the setting rather than reporting back simply empty white space. "You find nothing." is a valid answer, but it isn't always the best answer.
Short version: I detest 'no myth' theory, find it incoherent, and believes it encourages the worst possible traits you can encourage in a new DM (running on the seat of your pants). Very experienced DMs can run a session extemporaneously because they've got years of scenario experience to draw from. Don't try to do this as a novice. Don't plan to do this as an expert. You're doing exactly what you should be doing at this stage in your career, finding reliable published material and learning from it what works for your group and abilities and what doesn't.
There are some kernals of truth bedded in 'no myth'. It's possible to be too hidebound. One of the worst things you can do is assume the only things that exist are the things you've prepared for, because then you create a really thin world instead of a living one, and the players might as well be playing a video game instead of one based on collective imagination. But my advice to a new GM would be stay the heck away from anything to do with 'no myth'.
