Can we work on our gdd before the start of the jam? I always feel lost when I start a jam and it makes me second think myself

Concept art and documents are usually fine in these jams. I always have some loose design plans before starting to work on my submissions.

Making a gdd before the jam feels totally in the spirit of it! I don't tend to start a jam unless I have an idea I'm excited about, and a at least a bit of documentation about that idea.

I believe it's in the rules that yes, we can spend as much time as we want brainstorming on our projects, we just should try not to make anything tangible like code or assets before the starting date. I've been notebooking about my own idea too!