Game over
I could spend the next few hours writing about how the game went last night, but I still have six or seven submissions to read tonight, so I'll spare you the long version.
Short version: it mostly went well. The house was about the right size (we'd been worried about having 19 people wandering around in what is not really all that big a house), and pretty much everyone seemed to have a good time. The first half went quite well; I wandered around listening to conversations a lot, and even though most of these folks had never done any kind of roleplaying before, all of them were chatting away in character. The second half went a little less well; during the first half (the first two hours or so), there was some Big Event every 15 or 20 minutes, so everyone was kept on their toes, but we ran out of Big Events around halfway through, and some momentum got lost. Unfortunately, few if any of the characters actually achieved their goals for the evening (somewhere around the 4-hour mark we ended the game, because people were getting tired and I think a little bored, and frustrated with lack of progress toward goals), but one nice thing about this sort of LARP is that people can have plenty of fun even if their characters don't achieve their goals. Then there was an hour or so of everyone explaining all of their secret identities and special abilities.
That it went as well as it did is due partly to the players, partly to the writers of the game, and in very large part to Ethan, who did a stellar job as a first-time GM. He invented a reasonably simple but also reasonably plausible combat system (based loosely on the rock-paper-scissors system that the game creator provided); he did a huge amount of prep work and organization; he knew everything about all the characters; and he did a good job of coming up with creative ways of providing necessary information to characters during the course of the evening. I, in contrast, did a lot of standing around listening (which is really my favorite style of GMing; I like to sit back and let the characters interact, and provide answers to questions (and occasional earth-shattering external events and NPCs) as needed). I provided information as needed, but presented it pretty baldly, without gussying it up to fit characters well. I adjudicated a couple of disputes, but spent a fair bit of time going to fetch Ethan to ask his opinion or have him remind me of some detail I'd forgotten. (My biggest mistake was in not having read through the provided information enough times; I really didn't have enough of a grasp on the important details, and had to refer to character information sheets too often.)
I think that Ethan and I could probably, through some judicious nudging of certain characters, have gotten at least one or two of the plots to resolve a little more, which might've made for a more satisfying ending, with a bit more closure. But really, I think overall it all went pretty well.
There were some lovely moments, most of which aren't nearly as entertaining without knowing the backstory, so I'll spare you those as well. Suffice it to say that some of the characters could pick locks, and so material that was originally safely locked away ended up all over the place, sometimes without the GMs knowing it.
A couple of the players really outdid themselves, but one I'll single out for special kudos (not that he's likely to see this). One of the players (someone in a pretty central role) suddenly took seriously ill a couple days before the game, and wasn't going to be able to come. So one of the other players called up a friend who didn't know any of the other players (most of the players knew at least three or four of the other players) and invited him to join the game. Not only did he agree, not only did he spend most of the day Saturday reading and re-reading his character info sheet to prepare, not only did he arrive in a great costume, but he did a superb job of playing the character and of moving various plots forward.
'kay, I was gonna be brief, so I'll stop there.
Oh, except to say that if anyone wants to know more about this particular game, you can go to LARPA's free games page and download the "Marin County New Age Society Cocktail Party" PDF file, which contains almost all of the information about the story and the characters. But I don't recommend looking at that unless you're certain you're never going to play in it. Also note that it's something like 80 pages long; most of that length is devoted to character info sheets (there are at least 16 characters in the game).