About 50% of the time, the planned adventure for the night never went off as one of the yelled "squirrel!" and took off in an entirely unplanned direction which forced me to improvise on the spot.
that seems to be the case for most players and most games. sometimes I've been glad that the game is at least nominally restricted to a single star system at a time ....
(geez dude, you've been here for over 16 years! congratulations! I mean, if that's appropriate.)
Which is why I use the reaction table (or more properly my houseruled version of it) and the random encounter tables so much behind the scenes.
that's easy. what's hard is 1) making it all fit together and 2) not falling back too much on sterotypes.