It is currently unknown if it is mathematically possible to construct a quasi-symmetric magnetic field which upholds magnetohydrodynamic force balance, which is required for stability. There are stellarator designs which are very close to being quasisymmetric, and it is possible to find solutions by generalizing the magnetohydrodynamic force balance equation. Quasisymmetric systems are a subset of omnigenous systems. The Helically Symmetric eXperiment and the National Compact Stellarator Experiment are designed to be quasisymmetric.