Basically, I'd say only 10% of my adventures are scripted. Maybe even only 5%. Introduction, conclusion, plus a few waypoints: scenes that I really want or need to happen (because of their dramatic intensity, their necessity for the plot, and so on).
Then I need the other 90 or 95% of the adventures to actually <I>get</I> my players from scripted event X to scripted event Y. In fact, I found out that this was what worked best (with my players at least), since this ensures the shortest time spent planning the adventure (I know, I'm lazy) and the certainty that the players will have a very hard time doing something I wasn't prepared for (since I didn't expect anything specific, I'm prepared for everything
).
Then, all the while bringing my players from waypoint X to waypoint Y, I keep waypoint Y in mind so as to make sure it'll always be in front of the players ... well, if I consider that they deserve it of course, otherwise it'd be too easy
.
I like to consider it as an extremely complex maze: if the PCs have to chose from 3 corridors, whichever corridor they chose, if they had a very good reason (and actually did something) for chosing it or if I want them to feel lucky, it'll be the right one. If it was just random or if I want them to feel doomed, it'll be the one that ends in a pit. A scorpion's one preferably
. All in all, I'd say it's much more fun than having to actually draw all 3 corridors (i.e. plan everything the PCs might do).
Every procedure for getting a cat to take a pill works fine -- once.
Like the Borg, they learn...
-- (Terry Pratchett, alt.fan.pratchett)