If you want to maximize your chances of having a terrible hackathon, there are a few reliable strategies.
Arrive completely unprepared. Show up without a working environment, without knowing your stack, and without any sense of what you can realistically build in a weekend. Spend the first several hours installing packages, debugging setup, and learning things you should have learned before the event.
Bring the worst attitude possible. A hackathon is already sleep-deprived and chaotic, so the obvious move is to be negative, defensive, and impossible to work with. Make long nights feel longer. Morale is optional when you've already given up.
Assume your teammates are trying to mooch off you. If you really want to have a bad time, treat collaboration like a hostage situation. Interpret every question as laziness, every delay as incompetence, and every mismatch in output as proof that you alone care. Destroy any trust between you and your teammates. Discourage asking questions and expressing ideas as much as possible.
Start way too broad and refuse to cut scope. The best way to fail is to begin with an idea that obviously cannot be built in a weekend and then cling to as long as possible. Try to make a startup, a platform, a polished product, and a research prototype all at once. Reject any feedback that says otherwise.
Spend hours deciding instead of building. Burn your best hours debating ideas, switching stacks, changing direction, and searching for the perfect concept. Stop any chance at momentum. Make sure everyone is tired and behind schedule when you start.
Good luck!
This post is inspired by this video.