The Path forward to N$^3$LO

The LHC experiments will achieve percent level precision measurements of processes key to some of the most pressing questions of contemporary particle physics: What is the nature of the Higgs boson? Can we successfully describe the interaction of fundamental particles at high energies? Is there physics beyond the Standard Model at the LHC? The capability to predict and describe such observables at next-to-next-to-next-to-leading order (N$^3$LO) in QCD perturbation theory is paramount to fully exploit these experimental measurements. We describe the current status of N$^3$LO predictions and highlight their importance in the upcoming precision phase of the LHC. Furthermore, we identify key conceptual and mathematical developments necessary to see wide-spread N$^3$LO phenomenology come to fruition.