How to organize an in-person, online or hybrid hackathon -- A revised planning kit

Hackathons and similar time-bounded events are a global phenomenon. Their proliferation in various domains and their usefulness for a variety of goals has led to the emergence of different formats. While there are a multitude of guidelines available on how to prepare and run a hackathon, most of them focus on a particular format that was created for a specific purpose within a domain for a certain type of participant. This makes it difficult, in particular, for novice organizers to decide how to run an event that fits their needs. To address this gap we developed the original version of this planning kit in 2020 which focused on in-person events that were the dominant form of hackathons then. That planning kit was organized around 12 key decisions that organizers need to take when preparing for, running, and following up on a hackathon. Fast forward to 2025, after going through a global pandemic that forced all events to move online, we now see different forms of events - in-person, online, and hybrid - taking place across the globe, and while they can be all valuable, they have different affordances and require different considerations when planning. To account for these differences, we decided to update the original planning kit by adding a section that discusses the affordances and requirements of in-person, online, and hybrid events to each of the 12 decisions. In addition, we modified the original example timelines to include different forms and types of events. We also updated the planning kit in general based on insights we gained through continuing to organize and study hackathons. The main planning kit is available online while this report is meant to be a downloadable and citable resource.