If you’re a gamemaster (GM), you may have had this happen to you: for one reason or another, you’re about to start a game session, and you have not a clue about what your players are supposed to do during it. Maybe you forgot that you were running a session; maybe you’ve been tapped to run a game at a convention. Or maybe you’re just lazy. Doesn’t matter; what matters is that you need to put together something quick. As in, now. And you don’t want your players to catch on, or at least care too much.
Fortunately, there are things that you can do about this. To the bullet points!
First, you must panic. No, really, engaging in controlled panic is the absolutely first thing that you must do — unless you are one of those people who don’t need a certain amount of fight-or-flight hormones coursing through your biochemistry in order to wake your brain up fully. You just can’t indulge in it for long. It’s like using booze to calm down; a little actually works, but any more than that and you’re just asking for trouble.
Now that you’ve had your panic, the next step is to go out and steal something. Yes, steal. Are you getting money for running this gaming session? No? Then be shameless in your appropriation. Quick: what was the best game session that you’ve ever played in? No, don’t tell me, but answer the next question: did any of your players also play in that session? No? Then run the plot from that from memory. Heck, if any of them did play in that session then tip him or her the wink and let him or her take mild advantage of his or her foreknowledge.
If you can’t rip off somebody else’s campaign (or your own old campaign), rip off real life. News of the weird (I still miss the print version of the Weekly World News) is usually best, but regular news works, too. One point, though: when improvising, skip the entire ‘ripped from the headlines’ part. Your players have probably read the headlines, too. They may not have read a local news story about a sewer tax dispute where you’ve changed all the politicians to wizards and added zombies to the sewers.