> Uhm, sorry if i sound ignorant, but what's the point behind this? :-)
When the players want to play- they want options, powers, opportunities to do fun stuff. The GM has limitations of his own fun, time and effort. Discussion about these two things are key in developing a game that is both sustainable and fun for both parties.
As in the last part of it, a game can be much easier prepared when a group can manage both expectations, understand what they are after, and most importantly economise the effort involved.
As with the GM's own preparations, the players are also expected to prepare. Typically these expectations aren't discussed, there is that veil to be preserved and the GM's authority as well. There is an investment of effort and it can be such a waste at times. Waste that leads to frustration.
If the expectations are made clear and both parties can work out their tasks in the matter then there will be less chance for frustration and the chance to avoid it.
I've been using the Managing Projects Large and Small: the fundamental skills for delivering on budget and on time, by the harvard business school. I found it exactly what GMing is all about: organization.
The GM's perparation is one of the hardest task which can easily lose sight of its overall objective. Experience develops the practical aspect of it, books like Robin's Laws and the DnD DMG4e helps develop the theoretical side. Why let things as they are and frustration get to both players and gms, when it can be avoided by careful and efficient use of resources and time?