This year, I decided to take the plunge and run a theater-style LARP at GenCon. With 35 days left, my present-day self is wondering if my past self was a little overconfident about putting on a good show. If there's anyone out there who has run a LARP (or participated in one) and has any pointers, I'm all ears!

As some background, this is a homebrew murder mystery game that accommodates 6 to 15 players. I've budgeted 4 hours, with the first 30-45 minutes budgeted for rules/character overview, and approximately 3 hours of play time. I've run several murder mystery games; four were boxed sets and two were homebrew. I playtested this script with 15 friends this past weekend, and the initial reactions were positive. (There was also some excellent feedback, so I'm hopeful the second run will be better.) With as many as 15 players showing up to this event, I'll have one or two co-GMs.

Does anyone have any words of wisdom for a GenCon rookie? What general expectations do people have when signing up for a LARP? I've spent a lot of time on making the characters and story interesting, but my main priority is making sure the game is a fun experience for everyone.

Sounds like you're doing everything right.  You've got the right size game for your first time running at a con.  You did a playtest and got good feedback.  It sounds like you're doing another playtest to refine.  You've got people to assist you.  You're in the system and enough players have registered for you to run it.  You've got a good attitude and focus.  Cheers, you're in good stead!

The only advice I'd have is try to wrap game 15 minutes before the end of the time slot (the time listed is ending at 8:00 so try to wrap by 7:45) so that you can clear out the space for the next group and so your players don't feel like they have to choose between leaving early and missing their next event.  I'd also suggest keeping your 8:00 slot open so that you can chat with players afterwards and have those great, "What was the story behind X?"  Also so you can decompress, buy your co-GMs a drink, and enjoy yourself.

Good luck!

Thanks for the excellent advice! That all makes a lot of sense.

Plan for a lot more than 15 minutes of game time for wrapup. Half hour at least, depending on your format. If people are sneaking around and doing secret things all game, everyone is going to what to know what. 

Be prepared to break rules, throw out more clues, etc, if someone isn't enjoying the game for reasons you can control. Things you plan to happen won't all happen, players will do things you didn't expect, etc. So be ready to be light on your feet. And don't railroad, as much as possible. Let the players drive as much of the action as you can. 

Also good points-in past games at home, folks have hung around longer than I expected, so I'll block out 30 minutes or so for wrap up. I've also found that people tend to create their own red herrings, so I'll take your advice of throwing out more clues as needed to heart. Thanks!

For our 25+ person LARPs, we leave 45 min for wrap up, but we have a lot of sub plots and twists and secrets, so there's a lot to reveal. In fact, we have to ride herd a bit in wrap up to keep people from talking too much. Rather than asking "what did you do in this game?" we ask "so why were you trying to kill the Cardinal?" more directed, leads to a more concise answer. If other players want the nitty gritty details, they can talk afterwards.