At a convention, the DM must really clamp down. All the above principles become essential. Railroading? What kind: B&O, or a little Reading, perhaps? Subplots? Totally expendable. Having the rules at hand? Tattoo them to any exposed skin available. And most importantly, lock down the kind of nonsense at a table that can kill a group’s forward momentum. Find out who needs to be coddled and spoon-feed them to keep them involved before they get to be a distraction. Head off the rules lawyers. Get the the end, whatever that end is, to avoid that Bad Ending of quitting before the game should be finished.

So Sayeth Omnus.

Running games at cons is important as it lets people show off their favorite games to new vict… er, players and can get people to buy into new game systems and settings.

When running a con game you not only have a short session (4 hours IME) but you have no idea who/what is going to show up and how many (^ is the usual limit, less can show up.)

So running a game at a con is a unique challenge and a potentially rewarding experience as it can get in new gamers, or send then screaming into the night if handled badly…

And if they -do- veer off course, I only have to wing it for a couple of hours, then I have a whole week to prep something else!

* Big list of treasure? I email the list to the players between games and everyone can haggle over it between sessions. Ditto for identifying magic items and the like.
* The King has a mission he wants you to go on? My kings always summon the party to the throne room in between sessions. Then they give their long-winded description of what they want. This works really well because a) nobody interrupts the king (roleplay), b) everyone sees the whole message clearly, c) nobody interrupts the DM (Monty Python/Buffy/LOTR reference)
* Time in town getting new items is all handled between sessions. Each player has a dedicated email session to handle what they are doing with or without the other players. Somebody doing research gets their results. Then that player has to deliver the information to the party (fun when they forget stuff too!).
* Big battle coming up? Get the plan together between games. Sometimes, they have their own email separate from me so I get surprised by their strategy at the table. Those are great fun!
* Invites to the next game – I do a little recap to remind everyone where they are and what they are doing. I even BCC two spouses to remind them what nights husbands won’t be available.

I sometimes do little ‘behind your back’ writeups where the NPCs or the villains scheme behind the PC’s backs just for flavor or foreshadowing.

Email between games has really improved the enjoyment at the table!

Things I’ve found to be helpful:

Used the phrase “Time passes” when you want to get to the cool stuff. You can overdo this.

To get the group in the gaming mood, email them all a few days before the session with a reminder to have everything ready when they get there. Email them again the day before with the same reminder.

A Google or Yahoo Group is great for stuff that can be handled away from the table (buying/selling stuff, negotiations, travelogues, etc.). And IM sessions are great for solo play, so you don’t have to make four people wait while the fifth goes to chat with the local Thieves Guild…

I would add: steal something from the indie/story games crowd and give scene framing some thought in a shorter game. Make sure the scene is clear in your head, and that there is a clear reason for it being there. I hate, particularly in games like D&D, where half of a session is taken up shopping in the PhB or DMG for new equipment, or so a player can drag out a conversation with a “tavern wench” or something.

I’ve found that its pretty easy to gloss over unimportant scenes and events – fights the PCs will walk through without a problem, conversations that aren’t key to the storyline, and so on. That way, when you describe a scene in more detail and spent more time on it, everyone gets the hint that this is important…

As a sideline note…I know that I sometimes have a problem with railroading. My last campaign I really tried to improve it. When I asked my gaming group about it during a session their response surprised me. They wanted MORE railroading. The reason was the session length. With more direction they spend less time debating which direction to go. Don’t figure…

I don’t like to spend time on red herrings, either, but I’ve also eliminated “random” encounters and incidental combats that don’t pose a serious threat to the PCs. Chat-based combat just takes too long to waste the group’s time like that – any fight I expect to send their way is plot-related. The “set pieces” in the published Eberron adventures are the sort of thing I’m going for.

And it never hurts to roll initiative for all your opponents in advance. ; )

As for subplots, my group moves those forward in short-fiction interludes between the sessions. Luckily, though, much of what my players came up with dovetails into my overall plot, so they don’t “intrude” on everyone’s good time when they pop up in-session.