Official Rules:

1. No code written before the event. All code outside of open source libraries must be written at the event. If you use any code written specifically for this idea in advance, or work on a new project that is somehow related to an already existing company, you are not eligible for judging.
2. Allowed team size is 2 - 5.
3. No Remote participation
4. To be eligible for prizes, you must participate in at least one track challenge.

Also, don't be a dick. More specifically, refer to the MLH CoC here:

https://static.mlh.io/docs/mlh-code-of-conduct.pdf