I have run smallish conventions, I have run convention games, and I enjoy playing in convention games. I am looking forward to running 6 games in a couple weeks, and I have signed up to play in a couple games as well.
I have a belief though, that convention games need to do certain things in order to be successful:
-If you are running a demo of a game, showcase what the game is about, what the game can do; sell it. You have potential buyers of the game or folks who have already bought it and are fans.
-Handouts: have printed material ready; stuff players new and old to the game might need to look up. If you can facilitate transparency in your game, make it so it is less about the rules and more about the gameplay.
-Supplies: bring extra dice (heck, if you are promoting a game, buy some dice and hand them out), don’t be afraid of folks using your dice! Bring pencils, paper, tokens, anything the players might need.
-Nametags: given my druthers, I like having “Hello My Name Is” nametags, some folks find it dorky, so as an alternative, use a folded up index card and sharpie. This way the GM and players can all refer to each other in character. Let’s pretend it is a role-playing game, after all!
-Improvise: I put a lot of work into my scenarios (though it might not always show), but I am also willing to go in whatever direction the players want to drive the story.
-Make it a fun experience for every player: there are lots of different types of players, folks with greater mastery of these subtleties have written essays on them. All I will add is know your table, make sure to highlight every player and give them a chance to shine.
-Take as many players as you are comfortable with. I ran a game years ago that was supposed to be 6 players max, but I had prepped around twenty player-characters, so I ended up with 15 people at the table, anytime someone asked what was going on, I invited them to join.
-Make the player-characters cool. It is a con game. Let them be bada$$. Power creep be damned. Yes, there is joy in being the former farm boy turned hero saving the town from orcs, but give even that farmboy some cool stuff he can do! Personally, I want to play archetypes, I want to kick a$$ and take names, on the battlefield, at the bar, and in the boardroom!
-Help the players: you know the rules, help them out, suggest awesome combos they might not know because they might not know what the system can do. A basic attack in 4e is easy, but isn’t it much cooler to use a daily for 4d of damage? It is your job as GM to peel back the curtain and share with them all the cool stuff you put into all the characters, and even to divulge some of the awesome plot points you came up with. They will appreciate your hard work!
-And, lastly, have fun. Understand that every player or GM is there to have fun, as you are. Bring enthusiasm to the table and your fellow players and GMs will appreciate it. Be passionate, be excited, and work together.
Gaming is a communal activity, if we all work together to have fun, we will have fun!
And be sure to bring lots of cough drops, as you might lose your voice!