Are you a person who has an idea but can't execute it in the right time frame, but still want to join Game Jams for the fun of it? I know I am that type of person.
However, some people lean on their own understanding and those types of people have a lower chance of winning. Even then, they have a lower chance of their game being good. So they follow tips and participate in Game Jams for years until they get good scores.
I can help you do that! I've participated in 3 game jams so far and so I'm not exactly the new kid around the block. So let me guide you through tips and hopefully you would have a better understanding on Game Jams.
First tip: Always be productive. And by "always be productive" I don't mean procrastinate or drink 100 cans of Red Bull every day. No. What I mean is that you have to discipline yourself to work on the game submission every day. Always try to be productive, or, in other words, try not to have a 0% day. This way, you will be able to be more efficient, speed things up.
Second tip: Start small. If you have wild ideas, but you're participating in a game jam, don't do that wild idea. Try to make a very simple concept you think you will be able to develop in the shortest amount of time possible. As for this Multiplayer Game Jam, try to make the simplest idea possible. Your game doesn't have to be a graphical masterpiece, and it doesn't have to be the best idea possible.
If you think you can make your game the best by spicing it up with some eye candy and stuff, then go ahead. However, you should see if you can do it yourself first. I surely can't.
In the end, the game is all about the gameplay, and not about making it look good. If a book has vocabulary as good as Shakespear's plays, but it has bad story, then chances are it won't appeal as good as the author thought it would.
Third tip: Be happy with what you have. If you don't win, don't be upset. As a wise person once said, "Don't worry. Be happy." If you worry your game won't win, or if you don't win, don't worry at all. For all I care, there could be tens, hundreds, thousands of people who participated in the jam and they didn't win either. In the end, a game jam is about learning and meeting people. I'm not forcing you to be happy though.