The poser of each question is the sole and final arbiter of what constitutes a completely correct solution, who is the first to solve it, how much money a putative solution deserves, and all other terms of the offer. The wording of the problems given here is due to me, and the wording preferred by the problem posers may differ. If the ideas are interesting and especially if you crack one of the problems, I will try to get you in touch with the relevant problem poser or posers.
New contributions are always welcome.
I can't promise that I will include your problem in my list, but I will give it serious attention. The problems are listed by the size of the award, with the person offering the prize and the amount wagered for a completely correct solution. All problems so far offer the same prize independent of the answer to the question. A thrackle is a graph drawn in the plane with straight or curvy edges in such a way that any two edges either cross each other exactly once or share one endpoint, but not both. No other kinds of incidence between edges or vertices or self-intersections of an edge are allowed.