Wonderful guide, genuinely. I think community-run game jams are (almost) guaranteed to positively impact the forums, and most importantly, they’re really fun.
I guess if there’s anything at all I can personally add to this, it’s a mistake I made that I would love to talk about for anyone aspiring to run a game jam: stay on top of your competition.
It’s so easy to lose track and forget to announce a rule change or ask for a progress report. But contestants will have a hard time sticking to a competition or really caring about it if there’s a lack of effort from the host! It’s important to make the game jam feel less like the host’s a teacher assigning students an assignment with a deadline, and more like a fun test of a coder’s abilities. The best ways to do this have already been listed by @Taser, he did great on that.
An additional method of handling both picking contestants and dropouts is one from Unique-A-Thon 2: an applicant reserve system.
This was, however, something I could only accomplish because the competition had the hype to have multiple people apply to be contestants before the game-jam’s announcement (more than enough for the amount actually selected to join). I would also strongly suggest another measure, which is making sure applicants for the competition are made aware that they may be chosen for the applicant reserves, which would require them to be available to participate or take the place of a contestant who drops out.
And of course, you need to make your contest PRESENTABLE. Not necessarily saying to make your competition super upscale, but make sure to run your competition with pride! If a contestant asks you a question, answer adequately. Be professional in your topic post and in your replies. An identity for your competition wouldn’t hurt either. Don’t just post it under the name “Futuristic Game Jam”, come up with a name for your game-jam, honestly, even a logo wouldn’t hurt.
That’s all from me, though. I really don’t wanna take the shine from what is a very well-written, presented, and informative topic from Taser.
Best of luck from Unique.