Overview of fluctuations at the QCD phase transition in heavy-ion collisions

I will summarize our current understanding of the QCD phase diagram with special emphasis on what we can expect to learn from heavy-ion collision experiments. With the upcoming Beam Energy Scan Phase II at RHIC and the experimental facilities FAIR, GSI, and NICA, Dubna, several challenges need to be met both experimentally and theoretically. I will discuss in which aspects theoretical advances are necessary in order to be able to interpret the experimental results.